DFO Library MPO - Bibliotheque Final Report 14048291

Evaluation of the Applicability of Laser Depth Surveys to Canadian Nearshore Waters

Prepared for

Canadian Hydrographic Service Ottawa, Ontario

GC 10.4 .R4 Lit 093 Woodward-Clyde Consultants w 16 Bastion Square, Victoria, B.C. V8W 1H9 35( 1-1 -Li Final Report

Evaluation of the Applicability of Laser Depth Surveys to Canadian Nearshore Waters

Prepared for

Canadian Hydrographic Service Ottawa, Ontario

March 31, 1983

by E.H.Owens D.P.Krauel R.L.Keeney

GC 10.4 .R4 093 Owens, E.H. -Po -11 Evaluation of the ■ applicability of laser... AG 251474 14048291 c.1 Woodward-Clyde Consultants w 60928A 16 Bastion Square, Victoria, B.C. V8W 1H9 TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY 1.1

2.0 INTRODUCTION 2.1 Objectives 2.1 2.2 Report Format 2.2 2.3 Study Team and Acknowledgements 2.4

3.0 PRELIMINARY EXAMINATION OF FACTORS 3.1 The Problem 3.1 3.2 Conceptual Framework 3.2 3.2.1 General Features Affecting the Quality of the Data 3.2 3.2.2 Temporary vs Permanent Limitations 3.5 3.2.3 The Objective 3.6 3.3 Specific Assessments 3.6 3.3.1 Quality of Data Required 3.6 3.3.2 The Assessments 3.7 3.3.3 Comparison of the Assessments 3.9 3.4 Use of the Information 3.11 3.5 Comments 3.12

4.0 OPERATIONAL FACTORS - LASER SYSTEM 4.1 Introduction 4.1 4.2 Laser Design 4.2 4.3 Laser Operational Factors 4.3 4.3.1 Ice Cover 4.3 4.3.2 Turbidity 4.3 4.3.3 Wind 4.10 4.3.4 Bottom Reflectance 4.10 4.4 Marine Biological Parameters 4.11 4.4.1 Rooted Vegetation 4.11 4.4.2 Plankton 4.13 4.5 Detailed Examination of the Great Lakes Region 4.5.1 Subdivision la 4.15 4.5.2 Subdivision lb 4.17 4.5.3 Subdivision 2a 4.18 4.5.4 Subdivision 2b 4.18 4.5.5 Subdivision 3 4.19 4.5.6 Subdivision 4 4.21 4.5.7 Subdivision 5a 4.21 4.5.8 Subdivision 5b 4.26 4.5.9 Subdivision 6a 4.26 4.5.10 Subdivision 6b 4.27 4.6 Measurement of Water Clarity 4.28

5.0 OPERATIONAL FACTORS - FLYING 5.1 Introduction 5.1 5.2 Survey Logistics 5.1 5.3 Flight Conditions 5.3 5.4 Flight Safety 5.4

6.0 REGIONAL ANALYSIS 6.1 Introduction 6.1.1 Parameters Analyzed 6.1 6.1.2 Spatial Analysis 6.2 6.1.3 Temporal Analysis 6.5 6.1.4 Reliability of Information and Data Sources 6.8 6.2 Pacific Coast 6.2.1 Logistics 6.10 6.2.2 Physical Geology 6.10 6.2.3 Oceanography 6.11 6.2.4 Meteorology 6.14 6.2.5 Regional Analysis and Summary 6.16 6.3 Great Lakes 6.3.1 Logistics 6.33 6.3.2 Physical Geology 6.33 6.3.3 Limnology 6.36 6.3.4 Meteorology 6.37 6.3.5 Regional Analysis and Summary 6.37 6.4 Atlantic Coast 6.4.1 Logistics 6.61 6.4.2 Physical Geology 6.61 6.4.3 Oceanography 6.64 6.4.4 Meteorology 6.65 6.4.5 Regional Analysis and Summary 6.66 6.5 Hudson Bay/Labrador Coast 6.5.1 Logistics 6.87 6.5.2 Physical Geology 6.87 6.5.3 Oceanography 6.90 6.5.4 Meteorology 6.92 6.5.5 Regional Analysis and Summary 6.92 6.6 Arctic Coasts 6.6.1 Logistics 6.109 6.6.2 Physical Geology 6.109 6.6.3 Oceanography 6.112 6.6.4 Meteorology 6.113 6.6.5 Regional Analysis and Summary 6.113

7.0 ANALYSIS OF RESULTS 7.1

8.0 REFERENCES 8.1 LIST OF FIGURES

3.1 Factors influencing laser data accuracy 3.4 3.2 Preliminary assessments 3.8

4.1 Spectral attenuation coefficients of water 4.6 4.2 Percent transmission related to suspended matter 4.6 4.3 Water transparency in Lake Erie 4.9 4.4 Spectral attenuation coefficient for the Great Lakes 4.16 4.5 Secchi depths for Lake Huron 4.20 4.6 Water transparency in Lake Erie 4.22 4.7 Water transparency in Lake Erie 4.23 4.8 Water transparency in Lake Erie 4.24 4.9 Average water transparency in Lake Erie - 1965 4.25

5.1 Probability of success of airborne missions, southern Beaufort Sea 5.5 5.2 Mean number of days/year with thunderstorm activity 5.6

6.1 Canadian coastal regions 6.4 6.2 Data format for secondary parameters 6.6 6.3 Pacific Coast subdivisions 6.13 6.4 Composite distribution of the Fraser River sediment plume 6.15 6.5 Great Lakes subdivisions 6.35 6.6 Atlantic Coast subdivisions 6.63 6.7 Hudson Bay/Labrador Coast subdivisions 6.89 6.8 Arctic Coasts subdivisions 6.110 6.9 Sediment dispersal model for southern Beaufort Sea 6.114 LIST OF TABLES

4.1 Factors that Affect Laser Operation 4.4

5.1 Factors that Affect Flight Operations 5.2

6.1 Parameters that Limit Laser Bathymetry 6.3 6.2 Pacific Coast - Bathymetric Areas 6.12 6.3 Great Lakes - Bathymetric Areas 6.34 6.4 Great Lakes - Summarized Bathymetric Areas 6.34 6.5 Atlantic Coast - Bathymetric Areas 6.62 6.6 Hudson Bay - Bathymetric Areas 6.88 6.7 Arctic Coasts - Bathymetric Areas 6.111

7.1 Summary of Bathymetric Data 7.2

7.2 Summary of the Results 7.2

1.0 EXECUTIVE SUMMARY

1. The primary (permanent) limiting factors on laser bathymetry are water depth, ice cover and distance from an airfield. The latter was found to be non-limiting in Canada, but the ice cover criteria (mean open-water conditions for at least one month per year) excluded northern parts of the Arctic Archipelago from the analysis.

2. The most limiting of the secondary (temporary) factors was found to be water clarity. Turbid conditions, whether a result of biological or geological processes, would preclude operation of the laser technique.

3. The only region with a detailed data base is the Great Lakes; elsewhere, the evaluation involved considerable interpretation. Except in a few areas, for example, western Banks Island, the data base on water clarity was considered to be poor. Sufficient information, however, exists in most areas for the regional level of analysis that is the basis of this study.

4. The area of the Canadian shelf with depths less than 20 m is in the 2 2 order of 220,000 km : only 120,000 km (55 percent) of this was considered suitable for laser bathymetry at some time of the year.

5. Over 60 percent of the areas considered suitable for laser bathymetry are north of 60 °N.

6. Laser bathymetry would be limited to an area in the order of 45,000 2 km south of 60°N, due to constraints imposed by water depths and water clarity. Extensive shallow areas of the Lower Great Lakes, southern Gulf of St. Lawrence, and southern Hudson Bay have turbid waters that would probably preclude use of the laser system. 2 7. North of 60 °N, an estimated 75,000 km of charted or uncharted waters, with mean open-water conditions for at least one month each year, could be considered as suitable for laser bathymetry. The coasts adjacent to the Mackenzie Delta and the Plain of Koukdjuak are excluded due to high concentrations of suspended sediment.

8. Laser bathymetry could be considered as a viable method for reconnaissance surveys of uncharted or poorly-known waters in the Canadian arctic and subarctic. N O11. 0 110 0 81 N1 0/Z 2.0 INTRODUCTION

2.1 OBJECTIVES

The development of innovative techniques for the accurate measurement of water depths is a response to the increasing requirements for data. Present techniques for obtaining accurate depth information are based on the use of ships or launches equipped with echo-sounding equipment. Airborne measurement techniques could potentially become a cost-effective, rapid, and accurate means of hydrographic surveying in shallow waters. The development of an experimental airborne laser field system has matured to the degree that decisions on the wide-scale use of the system will be required in the near future. The primary objectives of this study are to define and evaluate the operational and environmental factors that control the use of the technique geographically and to identify areas of Canadian waters where the system would be a feasible hydrographic tool.

Water depth is the primary limiting factor for the airborne laser survey technique. Other parameters, however, that affect either the accuracy of the system or the operation of the aircraft must also be considered. An accurate evaluation of the applicability of the system, therefore, required initially the identification of the nature and the consequences of all significant factors. After this initial phase, the study progressed through an analysis, in time and space, of the controlling factors in order to determine in detail when and where the technique could be utilized. The waters adjacent to Canada's coasts were divided into a series of regions in order that data and information could be compiled to assess the local feasibility of the system. This approach provides an estimate of how much of Canada's coastal waters may be surveyed by the airborne laser method and also provides an explanation of how the various factors affect the use of the system. 2.2

The data base for this evaluation varies considerably in both quality and distribution. In order to estimate the feasibility of the system it has been necessary to interpret or extrapolate data and information in many areas. In order that these interpretations can be understood, the text of the study provides a background on the character and variability of the various parameters. The primary limiting factors are presented visually as a series of tables and the source of the data or information for each parameter is indicated to identify the level of reliability that can be assigned to the information.

The objectives of the study are to:

• determine the factors that control the field use of the airborne laser bathymetry system,

• estimate how much of Canada's coastal waters could be surveyed using the technique,

• present summary tables of the relevant data and information on a regional basis,

• define the accuracy and reliability of the data or information, and

• present summary maps that indicate areas where the technique would be a feasible survey option.

2.2 REPORT FORMAT

The first phase of the study involved a series of discussions that were conducted by Dr. R.L. Keeney to develop a conceptual framework for defining the factors that affect the applicability of the technique. On the basis of the preliminary examination of the problem (presented in Section 3.0), the various parameters that affect either the laser system itself or the flying operations are defined and described (Sections 4.0 and 5.0 respectively). These three sections provide the background to the analytical phase of the project.

The parameters that affect the operation or the accuracy of the laser bathymetry system have been evaluated on a regional basis. Canada's 2.3

coasts have been divided into five regions (Pacific, Great Lakes, Atlantic, Hudson Bay/Labrador, and Arctic). Each region was then further divided to give a total of 54 subdivisions. The analysis (Section 6.0) was confined to areas where water depths are less than 20 m, as this is the limit of water penetration for the system; within each region, these areas were both mapped and measured. For each of the subdivisions, a table indicates:

(a) the months in which the limiting parameters are a factor in affecting laser operations,

(b) the frequency within each month that the parameter is a factor (>20 days; 10-20 days; 2-10 days; <2 days; 0 days), and

(c) the reliability of the data or information presented on the table.

These tables are of value not only for the analysis that is presented in this study, but also in the evaluation of particular survey operations. If, for example, an airborne laser survey is to be considered for a particular section of Canada's coastal waters, reference to the appropriate table and sections of text would provide the necessary background for assessing the likely success of such a survey at different times of the year.

The text of Section 6.0 presents a description of the logistics, physical geology, oceanography/limnology and the meteorology of each of the five primary regions. This information is designed to provide an understanding of operational and environmental factors so that decisions regarding a field survey can be made in the context of the knowledge of how and why a particular parameter is present in the region.

A secondary product of the analysis is the identification of primary data and information gaps that would affect survey decisions.

The results of the project are reviewed and evaluated (Section 7.0) to summarize the applicability and feasibility of the airborne laser survey technique. 2.4

The report is accompanied separately by a series of maps that identify (i) areas of water depths less than 20 m, and (ii) within these areas where the airborne laser method is feasible. These five regional maps are at scales that range between 1:1,250,000 and 1:3,500,000; less detailed, page-size versions of these maps are provided in the relevant text of Section 6.0.

2.3 STUDY TEAM AND ACKNOWLEDGEMENTS

The study was designed and managed by Dr. E.H. Owens but involved the significant participation of a number of individuals. In particular, D. Monahan of the Canadian Hydrographic Service provided valuable input regarding the structuring of the problem. Drs. R.L. Keeney and J.R. Harper were closely involved in the preliminary phase of examining the survey factors. Dr. Keeney conducted interviews with D. Monahan and M. Casey of the Canadian Hydrographic Service and with Dr. R. O'Neil of the Canada Centre for Remote Sensing and prepared the text for Section 3.0.

The analytical phase, which constituted the major level of effort in the project, was carried out by P.D. Reimer and B.S. Sawyer. Dr. D.P. Krauel contributed to parameter definitions and prepared those parts of the text in Section 4 which relate to laser design (4.2), the laser operational factors (4.3) the water clarity of the Great Lakes (4.5), and to the measurement of water clarity (4.6). In addition, Dr. Krauel prepared those parts of the text and analysis tables in Section 6 that relate to water clarity. Dr. G.A. Robilliard and M. Bozeman prepared an evaluation of the marine biological factors for the analysis tables and Dr. Robilliard contributed the marine biology text for section 4.4.

The report was reviewed by Dr. W. Milne, and report production was the responsibility of J.L. Waring (word-processing) and B.S. Sawyer (graphics). N O IlV fl 1V A 3 A 8V NINI1 138d 0 -£ 3.0 PRELIMINARY EXAMINATION OF FACTORS

3.1 THE PROBLEM

The use of laser equipment from aircraft to chart the shallow waters off Canada's extensive coasts offers significant potential benefits. At the current time, however, the technology is new, relatively untested, and being improved both technologically and operationally by knowledge gained in field tests. The purpose of this section is to present a preliminary examination of factors affecting the breadth of application of the airborne laser technology. This examination was conducted as the first stage of the project and provided the framework for the analysis and evaluation that is presented subsequently in this report.

Because of the state of development of the laser technology, it is more of an art than a science to examine its applicability. Hence, it seemed particularly appropriate initially to discuss the equipment operation and uses of the resulting data with experts knowledgeable about these features. Specifically, the information gathered here relies heavily on discussions between R.L. Keeney with D. Monahan and M. Casey of the Canadian Hydrographic Service in Ottawa and Dr. R. O'Neil of the Canadian Center for Remote Sensing, also in Ottawa. Other individuals whose discussions were particularly important in preparing this preliminary examination were Drs. E.H. Owens and J.R. Harper of Woodward-Clyde Consultants. In all cases where judgement is attributed, the reader should recognize that these are definitely preliminary judgements and subject to change. They were gathered in short interviews for the purpose of beginning to structure factors that affect the applicability of the airborne laser mapping technique for shallow offshore waters. 3.2

The results of this preliminary examination are presented as follows. The first section (3.2) develops a conceptual framework for examining the factors affecting the applicability of the laser technology. Section 3.3 discusses specific assessments and judgements utilized to examine specific factors. Section 3.4 suggests how the information gathered might be utilized to help identify Canadian waters where the laser equipment may be a useful technological tool. The final Section 3.5 presents some general judgements on improving the information that is discussed and analyzed in this report.

3.2 CONCEPTUAL FRAMEWORK

The result of the hydrographic survey is a chart of shallow nearshore or offshore waters that indicates the depth at various locations. To evaluate the system technologically, the quality of the data is particularly important. There is, of course, some judgement about what quality of the data means. Based on discussions with the Canadian Hydrographic Service, accuracy is the key element in the quality of data for this preliminary examination. There are also questions about how accuracy might be measured. In this study, we did not examine this issue in depth. We basically utilized the standard deviation of the error in measurement as the index of the accuracy of the depth measurements. This index would presumably correspond with other indices that might be used, such as the maximum error.

3.2.1 General Features Affecting the Quality of the Data

In thinking about specific factors that might limit the applicability of the airborne laser mapping system, we begin by identifying the general features that might be limiting. Our thinking leads us to the following five features: • weather conditions • flying conditions • water conditions • laser operations • required data quality 3.3

The manner in which these general features relate to each other is illustrated in Figure 3.1. Here, one can see that weather conditions can directly affect all of the other features except required data quality. Weather conditions, however, indirectly affect the required data quality by their affects on these other features. The influence of one feature on another is indicated in Figure 3.1 by the arrows. Note also that there are arrows leading from boxes into all the general features except data quality. These boxes indicate the specific features that influence general features.

The specific weather conditions that may limit the applicability of the laser mapping technology include fog, cloud cover, humidity, rain, snow, and high wind. As an example, severe fog could prohibit flying because of concern for crew safety and for accuracy of the flight paths. The fog Ler se may not directly affect the laser operations or the water conditions. If the air is humid, this may affect laser operations by scattering signals sent from the plane and signals returned from the water surface and the bottom surface. This could lead to less accurate depth measurement and, in fact, inaccurate measurements. High winds could directly affect flying conditions and might create large waves with whitecaps, which would reduce the accuracy of laser operations.

Aside from weather conditions, the main feature affecting flying conditions would be the availability of landing sites for aircraft in the vicinity of laser mapping sites. For safety reasons, it would probably be necessary to have a minimum of one additional available site for landing (it need not be an airport; it might be a wide beach or a field) in addition to the site where the aircraft originated. Also, as accuracy in the flight path is essential for effective charting flying during night hours would probably not be useful.

Several specific features affect the water conditions in a way that is relevant to data quality. • These include the bottom depth, water clarity, bottom reflectance, wave size, and ice cover. The interaction

3.4

1 Weather Conditions \ / \ / Water Flying Conditions Conditions

Data Laser / Quality Operations

Figure 3.1 Factors influencing laser data accuracy. 3.5 between water clarity and water depth is particularly important. As the water clarity decreases, the depth decreases to which the laser mapping equipment is accurate. Stated alternatively, for a particular depth, the accuracy of the laser mapping decreases as the clarity of the water decreases. There are numerous factors that affect the water clarity including the concentration and type of suspended solids, the dissolved organic material, and the chlorophyll concentration. The operation of the laser equipment can also be affected by waves that are either too big or too small. The system does not operate with ice cover.

Most of the features affecting laser operation are indirect, in that they result from either weather conditions, flying conditions, or water conditions. Even when these conditions are not limiting, however, there may be concern for the safety of individuals, which could limit the applicability of the laser system. Specifically, one might not wish to use lasers in an area where individuals were either on the shore (e.g., a beach) or near the shore (e.g., in small fishing boats) for fear of personal harm. The vision of an individual looking toward the aircraft could be severely impaired if the laser equipment was operating in their direction. The time of year, which effects solar illumination and radiance angle, can also influence laser operation.

3.2.2 Temporary vs. Permanent Limitations

In examining the features that potentially limit the use of the airborne mapping system, it appeared to be particularly useful to differentiate between those that had a permanent affect and those that had a temporary affect. Although in some cases the distinction is not completely clear, the concept should be very useful. For our purposes, we consider the permanent limitations to be essentially three factors: water depth, ice cover, and availability of bases for operating aircraft. All other specific features are considered to be temporary features. Water clarity, for example, would prohibit the usefulness of the equipment but in some areas there may be times when the clarity would improve at the 3.6

particular location such that it would be possible to effectively utilize the laser equipment. The permanent limitations are related to present-day considerations. At a time in the future, one might develop base sites for aircraft where additional areas could effectively be mapped. In addition, a change in the equipment utilized for mapping, such as from fixed-wing _ aircraft to helicopters, might increase the area that could effectively be charted with the laser system.

3.2.3 The Objective

In the next sections of this report, the objective is to obtain a preliminary index to indicate the areas of the coast that can be effectively charted as a function of the two most critical factors that affect the laser system: water depth and water clarity. One could easily combine this with a separate, independent examination of the areas that could effectively be mapped as a function of the availability of base facilities for aircraft. This would depend on the range of operations and types of aircraft, and since this particular investigation did not examine those aspects in detail or include experts on aircraft operations, it is not further addressed in this section.

3.3 SPECIFIC ASSESSMENTS

This section discusses the quality of measurement required for the laser technique to be useful and the assessment of the combinations of water clarity and depth where such a technique is technologically feasible.

3.3.1 Quality of Data Required

Since the primary user of the hydrographic data is the Canadian 'Hydrographic Service, we chose to use their guideline for determining the appropriate quality of the data. The guideline used by the Canadian Hydrographic Service is that the error in measurements should not exceed 30 cm for depths up to 30 m and should not exceed one percent of the actual depth for depths greater than 30 m. Since the laser equipment would only 3.7

be utilized for depths of 20 m or less, the appropriate standard for laser accuracy would be 30 cm. There is, however, an option for how one wishes to define error in measurement. As mentioned above, in this investigation, we utilized the standard deviation of the measurement error as the measure.

3.3.2 The Assessments

Before we actually determined the required quality (i.e., <30 cm) for the laser measurement system, assessments were made with staff of the Canadian Hydrographic Service (C.H.S.) and the Canadian Center for Remote Sensing (C.C.R.S.) to appraise their judgement of the errors that might result from various combinations in water quality and depth. The results of both of these preliminary assessments are indicated in Figure 3.2. Some interpretation of this figure is certainly necessary.

Let us first consider the assessments with the Canadian Hydrographic Service. In this case, the water depth was measured in metres, ranging from 0 to 20 m, and the water quality was measured in terms of the Secchi depth, which we shall indicate by the symbol Z. A Secchi depth of 5 m would indicate that a disc lowered 5 m in the water could just barely be seen and would not be seen at greater depths. Thus, a Secchi depth of 15 m indicates that the water is much clearer than a Secchi depth of 1 m. Questions were asked such as the following: "At a depth of 10 m with a Secchi depth of 15 m, what is the standard deviation of the error that you would expect in laser measurements?" The response for this particular combination was 21 cm as indicated in the circle at the location of a 10 m depth and a 15 m Secchi depth in Figure 3.2. The responses of the C.H.S. staff are indicated by the circled points on that figure. It is useful to note that the accuracy of the equipment decreases when the depth increases or when the Secchi depth decreases. This directional degradation of the laser charting procedure seems reasonable. However, because the charting technology is very new and because there have been limited field tests, the specific numbers should be considered very preliminary.

3.8

Diffuse Attenuation Secchi Coefficient Depth k

3 — 0.5m - 2 — 0.75m- 1.5 lm - 1.0 1 5m _ • 30 • 1501 • kDmax =20 0.75 2m _ 1501

0.5 — 3 3m - • 30 30 •

0.33 5m - 3Z=Dmax

1 0

10 10 15 0 0 15 /0 10 15 20 DEPTH (m) Assume 1(2=1.5 0 CHS Preliminary assessments 20 CCRS Preliminary assessments

Numbers represent estimated standard of error in measurement (cm).

Figure 3.2 Preliminary assessments. 3.9

In the assessments with the staff of C.C.R.S., the depth was again measured in metres ranging from 0 to 20 m. However, in this case the water clarity was measured by the diffuse attenuation coefficient, which we will 1 define as k and has units of m . When the parameter k is small (near -1 0.1 m , for example), the water is very clear. As k increases, the clarity of the water decreases.

The assessments for the error as a function of the diffuse attenuation coefficient and depth gathered from C.C.R.S. are indicated by the boxes in Figure 3.2. As before, they should be considered preliminary. In this assessment, they also should be considered to indicate the potential of the laser equipment to operate once the operating procedures are refined, rather than given the operation procedures that might be utilized at the present time. In other words, these errors indicate errors of operating with very good procedures and with very good conditions, as opposed to operating with current procedures under normal conditions which was the assumption with the Canadian Hydrographic Service estimates. This fact must be kept in mind when comparing the two assessments.

3.3.3 Comparison of the Assessments

One observation that can be made in comparing the assessments is that, in both cases, the perceived error greatly increases as the depth of the water increases or as the water clarity decreases. To make any further comparisons, however, one needs a relationship between the two different scales utilized to measure the water clarity. Although there is no unique relationship, there is some evidence to indicate that a reasonably good relationship is simply kZ = 1.5. This is the relationship utilized in Figure 3.2. With this relationship, the absolute errors indicated in the figure are relatively close for the two assessments. This is particularly true when the unit utilized by one person, for error might be different from the unit used by another person and when the relationship between the two clarity measures is not unique. 3.10

The staff of the Canadian Hydrographic Service suggested that the laser equipment might be useful operationally for charting waters where the depth was no greater than three times the Secchi depth. In this case, if we define D to be the maximum depth to which the equipment can be max usefully operated, then Dmax = 3Z. This operating limit is indicated on - Figure 3.2. Specifically, the area below the line 3Z corresponds to the conditions under which the laser equipment can be effectively used.

Dr. R. O'Neil of the C.C.R.S. considered that the laser equipment had the potential to be effectively operated in conditions where the depth is less than D = 20/k. The line where kD = 20 is also indicated on max max Figure 3.2, and the area under that line would correspond to the conditions under which the laser equipment would potentially be useful using Dr. O'Neil's judgement. Given all the caveats that we have discussed above concerning comparison of different indices for water quality and different concepts of error, we note that the area corresponding to conditions where the laser equipment might currently be utilized is less than that where it might usefully be utilized with more field testing and knowledge to improve operating conditions and the technology. This also indicates the time dependence of the judgements expressed in this study. They currently must depend on the technology available and the knowledge of existing field tests. Since these change in time, the judgements will change also.

It is important to note on the data in Section 3.3 that it may be the case that the accuracy goal of 30 cm for depths up to 30 m might not always be achieved when the conditions for operating the laser equipment hold. That is to say, the laser equipment may operate, but may result in errors of, for instance, 50 cm. With the current standard of the Canadian Hydrographic Service, such errors would not be acceptable. Therefore, in deciding what part of Canadian waters can effectively be charted, one might simply not ask, in what areas can one gather the data, but also, is it accurate enough even if one can gather the data? From the assessments in Figure 3.2, it appears that for both the assessments of the Canadian Hydrographic Service and the Canadian Center for Remote Sensing, to limit the applicability of the data to areas where the error is less than 30 cm 3.11

would be more limiting than simply to utilize the lines indicated on Figure 3.2 to define the maximum range of operations. Stated another way, using C.H.S. information, their judgement of the error is greater than 30 cm in some areas where the depth is less than 3Z. Using C.C.R.S. judgements, the error is greater than 30 cm in some of those conditions where the depth is _ less than 20/k. Such circumstances need to be considered in examining the Canadian waters in which the equipment may be applicable.

3.4 USE OF THE INFORMATION

Based on the preliminary judgements indicated on Figure 3.2, it would appear that the operational usefulness of the laser equipment, at the current time, would correspond to areas under the D max = 3Z line. In the near future, the total areas might be increased to that under themax D = 20/k line. Thus, it would appear useful to geographically indicate those areas of the Canadian coast corresponding to the area under both curves and then those corresponding to the area under the higher curve in Figure 3.2. Areas of the Canadian coast with conditions greater than the higher curve might be considered inappropriate for laser charting.

For those areas where laser charting seemed potentially useful, it would be necessary to check the existence of the other temporary factors to determine the degree to which these might prevail. For the current time, it might be useful simply to indicate a percent of the time over a period of a year where conditions would not necessarily inhibit use of the laser equipment in order for the laser system to be useful. Preliminarily, based on discussions described here, one might consider it possible to use the laser equipment as long as the temporary conditions did not hold in a period of over 25 percent of the time during a particular one-month period. Thus, for instance, if conditions at a particular location were such that one expected 10 days in the month of July to be sufficient, in terms of the temporary conditions for laser mapping, it might be reasonable to assume that laser mapping would be technologically applicable to that area if the permanent conditions were such that laser mapping seemed appropriate. This figure of 25 percent of a one-month's period is based in large part on the author's judgement of qualitative information gathered in the discussions. 3.12

The other factor that it would be necessary to examine is the availability of land bases to support the aircraft equipment necessary for the mapping techniques. As mentioned in Section 3.2, this examination should be rather straightforward and could be conducted independently of the investigation referred to here. The information needed is the maximum distance from a landing site under which the pilots can safely operate planes, and a knowledge of the location of the primary and alternate landing sites.

3.5 COMMENTS

It is perhaps useful to mention that, in any study of this nature, professional judgements and value judgements are absolutely necessary. There is no way around this fact; there are simply different ways to proceed. Specifically, one might try to hide those necessary judgements in a vail of "objectivity" or one might try to bring them explicitly to the forefront to promote clear examination. The latter was the purpose here. The intent is that by making these judgements clear, we can improve communication and promote modification and improvement.

There would seem to be four general types of improvements to an investigation such as described in this section. Each would require more time than that allocated to this study, and the appropriateness of each could better be appraised as a result of this preliminary investigation. The four potential improvements are the following:

(1) Improve the quality of the information indicating the perceived error due to operating the equipment in conditions of different water depth and water clarity. (2) Investigate quantitative restrictions on the operational usefulness of the equipment due to temporary factors. (3) Investigate the accuracy required from charts as a function of the uses of the charting information rather than simply accept a 200-year old historical standard of 30 cm accuracy. (4) Conduct these assessments with a wider range of experts, knowledgeable and concerned about hydrographic mapping. 1:13SV 1 - S1:1 010V A 1VN OLIVEI3d 0 017 4.0 OPERATIONAL FACTORS - LASER SYSTEM

4.1 INTRODUCTION

The successful planning for the implementation of a laser survey requires consideration of a wide range of operational factors that relate to either the laser system itself (this section) or to the flight component of the survey (Section 5.0). The factors that limit survey logistics or the measurement technique are described in these two sections and are discussed, on a geographical basis, in the analytical phase of this feasibility study that is presented in Section 6.0.

In considering the wide range of factors that can affect an operation, it is initially evident that some factors are permanent, such as the distance between an airfield and the survey area, whereas others may vary both in time and space (Section 3.2.2). For the purpose of this study, water depth is considered to be a permanent factor, even though in some areas the movement of sand waves can, for example, result in depth changes in the order of several metres. These factors that vary through time may do so in a reasonably predictable manner, for example, the growth and decay of the sea-ice cover or seasonal wind patterns, whereas others may be almost random in character, such as turbulence or local wind patterns.

The discussion in this section focusses initially on the principles of the laser system for bathymetric surveys, and then considers those fac- tors that limit field operations of the equipment. Marine biological para- meters that affect water clarity are discussed separately in Section 4.4. In Section 4.5, a detailed examination of the spatial distribution of the limiting parameters for the Great Lakes is presented, and Section 4.6 outlines a number of methods that are available to measure water clarity. 4 . 2

4.2 LASER DESIGN

The laser measures water depth directly by transmitting pulses of green light that are reflected from the water surface and from the bottom. The time difference in reception of the two reflections by the aircraft- mounted instrument provides a measure of the water depth.

The MK II Lidar delivers up to 10 MW peak pulse power at 532 nm and 15 MW pulse power at 1064 nm (Ryan and O'Neil, 1980). The output pulse width is 5 ns and the pulse repetition rate is variable from single shot to 10 pulses per second. At the largest repetition rate, the water-depth sampling interval is approximately 7.6 m for an aircraft flying at a ground -1 speed of 76 ms (150 knots). The maximum depth penetration, Dmax , of the laser can be expressed as (Steinvall et al., 1981)

-D - 2KD max = kn P/P or P = e max B P 2K B where P is a system parameter defined by

P = P • p • A • n /7 • H2 L r r in which P is the laser peak power, p is the bottom reflectivity, A the L r receiver area, nr the receiver efficiency, and H the altitude. The optical background level received by the detector is denoted P and the system loss B is described by the exponential loss coefficient K.

Although the relationship would indicate that the depth penetration can be increased by increasing the laser power or the receiver area, there is a limit to the maximum depth penetration that can be achieved in this manner due to an associated increase in background noise, P B , from backscatter.

The ratio, can be considered to be the signal-to-noise ratio P/PB' of the system. The system attenuation coefficient is essentially equal to the diffuse attenuation coefficient, k (Guenther, 1978). Therefore, the product of the diffuse attenuation coefficient and the depth beyond which successful returns cannot be detected, is a useful system parameter Dmax, for a laser hydrographic surveying system. 4.3

4.3 LASER OPERATIONAL FACTORS

The maximum operational depth for this study was taken to be 20 m with a depth measurement accuracy of + 0.30 m. As noted in Section 3.0, there are a number of parameters that can be limiting environmental factors for the operation of the laser. These are listed in Table 4.1, with the corresponding range of values under which the operational requirements are met, and that are described in the following sections.

4.3.1 Ice Cover

The laser beam will not penetrate ice; hence, the presence of ice prohibits the use of the laser for hydrographic surveying. Since the presence of ice blocks the penetration of the laser beam into the water column, the operational period for the use of the laser on any coastline must be limited to the local ice-free season.

4.3.2 Turbidity

Water clarity or turbidity is the most critical limiting parameter for the successful operation of the system. Over the years, many different techniques have been employed to measure turbidity or the optical properties of seawater and freshwater (see section 4.6: page 4.28). Properties that indicate the optical character of water include: transparency; beam attenuation coefficient; colour; and vertical extinction coefficient or diffuse attenuation coefficient. These optical properties have the following definitions: • Percent transparency is a measure of the amount of radiation that successfully transits a unit length.

• Transparency, as measured by a Secchi disc, is the average of the depths at which the disc disappears and reappears.

• Beam attenuation coefficient is the measure of the attenuation of a collimated light beam through a fixed path length.

• Colour is described by comparison with some scale, such as the Forel-Ule Scale.

• Vertical extinction coefficient, or diffuse attenuation coefficient, is a measure of the exponential attenuation of downwelling radiation in the sea. 4.4

Table 4.1 Factors That Affect Laser Operation

PARAMETER OPERATIONAL REQUIREMENT

Water Depth <20 m Ice open water Secchi depth >6.7 m 1 Diffuse attenuation coefficient <0.22 m Percent transparency 50% per metre -1 Wind 1 - 10 ms Bottom reflectance not limiting Seaweed none present 4.5

The Secchi disc, a white, 30-cm diameter disc, has been widely used to measure water transparency. It has been found that the Secchi depth is influenced by shade from direct sunlight, observer, height of observer above the water, altitude of the sun, and clearness of the sky.

Many observers (Tyler, 1968) have attempted to relate the Secchi depth to beam and diffuse attenuation coefficients. Such relationships are by no means exact and have moderately large standard errors. The relationship between diffuse attenuation coefficient and the Secchi depth is usually approximated by the equation

kZ = constant where k is the diffuse attentuation coefficient and Z is the Secchi depth in metres. The constant has been quoted to be in the range 1.44 to 1.7 and is normally taken to be 1.5 (Frederick, 1970).

The diffuse attenuation coefficient is normally measured by the use of a submarine photometer and the equation

I = I e-kz Z o where I and I Z o are the intensities of solar radiation at the surface and at depth z respectively. The diffuse attenuation coefficient is a measure of the absorption and scattering of the water and the suspended matter within the water column. The coefficient is a function of the light wave length. The relationship varies with location, but all waters tend to have a minimum value of the attenuation coefficient in the green band of the spectrum (Fig. 4.1).

Many attempts have been made to relate the diffuse attenuation coefficient to the beam attenuation coefficient, the water colour, or the concentration of suspended material in the water column. The latter parameters must be depth-averaged to make them comparable to the beam 4.6

0.7

0.6

E 42- 0.5 Coo„ •

''ro/ , '40,4.

407) 04 0 .--1 ...- „, •0_ - _ , t0.3 A: I , - - --_ - . • Coastal min 0 . 2 ....„.....Oceanic max '

0.1 Oceanic mean e. I ceanic min

045 Blue 0.50 Green 0.55 Yellow 0.60 Orange 0.65 Wavelength, microns

Figure 4.1 Spectral attenuation coefficients of pure water and various types of seawater (after Sverdrup, Johnson, and Fleming) (Note: 1 micron = 1000 nm).

100 -

•• • 75 - • • • • • • N MO • • • • • • SSIO 50 - • SMI • • • • 25- • TRAN 0 0• • • 0 0 0 • • • 0 • •• CO 1 10 100

CONCENTRATION (gm-11

Figure 4.2 Percent transmission as a function of concentration of suspended particulate matter. 4.7

attenuation coefficient or the Secchi depth. These relationships have large standard errors since other parameters must be taken into consideration.

For example, the relationship between the diffuse attenuation coefficient and concentration of suspended particulate matter depends upon the ratio of organic to inorganic material, the size and density of the particles, and the amount of dissolved organic material in the water. Figure 4.2 displays the relationship between the percent transmission per metre and the concentration of suspended particulate matter. The scatter of the data points indicates the uncertainty of a relationship between the two parameters. Even at very low concentrations, the light is significantly attenuated in natural waters due to absorption by dissolved organic material.

The diffuse attenuation coefficient would be expected to increase in and near estuaries due to increased concentrations of dissolved organics, probably humics. Additionally, the freshwater sources will probably carry increased suspended solids into the marine environment, especially during freshets, which will also increase the coefficient. Organic suspended particulate matter would be expected to peak locally in coastal waters during phytoplankton blooms in the spring or early summer (see Section 4.4). A typical bloom may lead to chlorophyl concentrations of 10-20 mg -3 -1 m and a diffuse attenuation coefficient in the range of 1.0 - 1.5 m or more.

Variations in water clarity are related to areal distributions of dissolved and suspended material, which in turn are related to particle size, composition of the bottom sediment, proximity to the shore, depth of water, currents, storm activity and depth of mixing caused by resulting waves, variation in streams influx, windborne materials, and plankton blooms. The most significant short-term variations are produced by storm activity and plankton blooms. 4.8

The staff of the Canadian Hydrographic Service interviewed in the initial phase of this study (Section 3.0) suggested that the laser bathymetric system might be operationally useful for mapping waters in depths less than three times the Secchi depth

i.e., Dmax = 3Z or D = 4 ' 5 max — k

Since the maximum operational depth desired is 20 m, the system will be operationally useful in water with a Secchi depth greater than 6.7 m or a -1 diffuse attenuation coefficient less than 0.22 m . The beam attenuation coefficient, which is frequently observed by a transmissiometer, is approximately five times the diffuse attenuation coefficient (Guenther, 1978). Therefore, if the depth-averaged beam attenuation coefficient were -1 less than 1.1 m , the laser system would be operationally useful. These values have been determined for a 20 m depth. If the actual bottom depth is less, the required optical parameter values could be relaxed accordingly.

It is important to use a depth-averaged optical parameter, since the distribution of properties contributing to attenuation is not uniform over the water column. Larger particles, especially those which have a higher density than the water, settle rapidly. The settling of finely divided particles, with densities approaching that of water, is greatly affected by temperature and salinity variations and stratification. This creates a natural separation based on size and composition. Organic material especially tends to concentrate above the pycnocline, as settling is impeded by the underlying water of greater density and viscosity. Below the thermocline in lakes, the settling rate is more uniform because the hypolimnion is structurally more stable than the epilimnion. Suspended material may concentrate near the bottom. These materials may be colloidal or they may be due to transport or resuspension of materials. Direct correlations between transparency and temperature structure have been found in lakes. The lowest transparency has been found below the thermocline and above the sediment-water interface. This phenomenon was observed repeatedly in the Corps of Engineers study of spoil disposal effects on the Great Lakes (Fig. 4.3). 4.9

42.38° N 42.35 ° N 42.25° N 42.31 ° N 42.35° N 81.61 ° W 81.37°W 81.32° W 81.08°W 80.85 ° W 0

N ct w 10 w

0. 20 w

30 PERCENTAGE Figure 4.3 Vertical profiles of water transparency in Lake Erie (Pinsak, 1968). 4.10

4.3.3 Wind

Wind and wind-generated waves influence the system performance in a number of ways, all of which are significant only at the extremes (Guenther, 1978). A glassy or mirror-like water surface, such as would occur during calm wind conditions, causes the surface return probability to decrease. Surface return energy from non-nadir scanner angles reaches the receiver only if capillary waves are excited sufficiently to present a large number of tiny facets perpendicular to the beam. These capilleary -1 waves tend to die out due to surface tension for wind speeds below 1 ms , which leads to a reduced detection probability. At the other end of the spectrum, high winds generate waves that, in shallow coastal areas, resuspend bottom sediments and decrease water clarity to unacceptable -1 levels. From 1 to 10 ms (2-20 knots), beam spreading through the air-sea interface due to wave-slope augmented refraction is small compared to beam spreading in the water column due to scattering, but, at higher wind speeds, the beam spreading by the surface waves is of a magnitude sufficient to reduce the detection probability.

Therefore, the operational window for the system is limited to winds -1 within the range 1-10 ms (2-20 knots).

4.3.4 Bottom Reflectance

Reflectivities for sediments consisting of various grades of mud, sand, and shell fragments have been found to range between 4 and 12 percent (Guenther, 1978). Although the reflectivity of bottom sediments is not considered to be a limiting factor, the presence of vegetation will significantly attenuate the laser beam and may result in reflections that will cause a shallow bias in the soundings. Hence, the presence of seaweeds, whether floating on the surface or in the water column, or fixed to the bottom, will adversely affect the use of the laser bathymetric system. These biological parameters are discussed in Section 4.4. 4.11

4.4 MARINE BIOLOGICAL PARAMETERS

The abundance of floating or rooted vegetation and plankton is one of the primary factors that affects water clarity. Floating vegetation, including duckweed, filamentous algae, and water hyacinths, is not generally a problem, except in some lake environments due to its limited distribution.

4.4.1 Rooted Vegetation

Rooted vegetation includes: (i) kelp, which has a floating component or canopy as well as the stalk and holdfast; (ii) seagrass, principally eelgrass and surfgrass, (Zostera spp. and Phyllospadix spp., respectively); and (iii) other plants such as water lilies in lakes.

Kelp is comprised of several species. The principal Pacific Coast forms are those that reach to the surface, including: • Bull Kelp - (Nereocystis and Keana) is abundant along much of the rocky, exposed to protected coasts of Vancouver Island, the Strait of Juan de Fuca, the Queen Charlottes, and the exposed mainland coast. It is common in areas of rocky bottom and where there is not a substantial, long-term, low salinity discharge. It grows from nearshore (>5 m) to depths where sufficient light can penetrate (up to 25 m). It probably reaches heights >1 m in March, the surface in May-June, and is torn out by storms in October-November. Thus, bull kelp, by itself, will limit the use of the laser system to winter months along much of the rocky coast of B.C.

• Kelp - (Macrocystis integrifolia) is abundant in less exposed, higher salinity patches, especially the coasts of Vancouver Island and the Queen Charlotte Islands. It is not present on the Inside Passage. It grows in depths to 10 m from the shore. It is a perennial and may be present most of the year, even if the surface canopy is absent. That is, it will have stalks, fronds, or air bladders present on the bottom, extending up to a metre upward. In general, it is not as widespread on the coast as is Nereocystis.

Brown kelps, (Alaria, Laminaria, Hedophyllum) are all abundant on rocky bottoms from the shore to approximately 20 m depth, depending upon light. They are often more than a metre tall and form an essentially complete carpet in many areas. 4.12

Red kelps, (Gracilaria and Gracilariopsis) are also abundant on rocky bottoms, especially on the southeastern coast of Vancouver Island. Several other large red algae may be abundant.

Though the species-specific abundance percent cover and height varies temporally and spatially for these red and brown algae, in aggregate they generally constitute a vegetation layer up to 1-2 m deep on rocky bottoms to 20 m depths. Consequently, the laser may not be able to detect the "true" bottom in these areas. The only areas where some large algae are not likely to be present are (1) vertical walls such as along fjords, (2) low salinity areas like the Fraser River Delta, (3) sedimentary substrates, or (4) high turbidity plumes.

The major kelp species on the Atlantic Coast are Laminarians, especially Laminaria digita and L. longicruris, and Agarum cribrosum. They dominate in shallow water (less than 15 m) along the New Brunswick, Nova Scotia, Newfoundland, and Labrador coast to Hudson Strait. They are found mostly on the exposed coast, and probable heights exceed 1 m. Most rapid growth is in winter. They cover most of the bottom, but are probably not abundant in bays or the inner (low salinity) Gulf of St. Lawrence. Kelp of the west coast type are not present on the east coast because they are eliminated by winter ice.

Seagrasses are of two types. Surfgrass, or Phyllospadix, is only abundant in the immediate surf zone of exposed to semi-exposed rocky shores where salinity is high, principally on the west coast. These represent a minor problem for laser operations because, although grass can be over 2 m long, it rarely occurs in water below zero datum (MLLW).

Eelgrass may be very abundant on sedimentary bottoms in bays, estuaries, and other low-medium salinity habitats where wave energy is low. Depth range is limited by light penetration but may be up to 7 m. Eelgrass may reach 2 m in height in late spring to late fall. It often dies back in winter to 1 m and is less dense. Irish moss is present in many shallow rocky Atlantic coastal waters. It is a perennial that grows up to 50 cm between the low water mark and 10 m water depths. Eelgrass is abundant and, as a result, the laser technique would be ineffective in 4.13

most Pacific coast bays and estuaries, and probably in many Atlantic coast bays, especially south of Labrador.

4.4.2 Plankton

Plankton occurs in densities great enough to limit light penetration of the water column (Section 4.3.2) and will limit the effectiveness of the laser to penetrate to the bottom.

Plankton is comprised of plants (phytoplankton) and animals (zooplankton), which are mostly small (usually microscopic as individuals) and at the mercy of the currents with regard to their primary movement and distribution patterns. Plankton are distributed throughout the water column, but by far the highest abundance and diversity occurs in coastal waters; i.e., the area of interest for using the laser technology.

The abundance or density of plankton populations varies by orders of magnitude between seasons as well as between major oceanographic regions. The peaks in abundance, especially for phytoplankton, are known as "plankton blooms". It is during these blooms that the densities become so great that water clarity is reduced, often to the point where Secchi disc readings are <0.3 m and may approach zero in extreme cases.

Phytoplankton blooms typically occur in the spring and again in the fall. The first (spring) bloom is the result of: (1) river and land surface runoff, which brings large amounts of organic and inorganic nutrients into the marine system; (2) an increase in day length and a decrease in sun angle, which allows deeper penetration of light into the water column, both of which allow longer periods for photosynthesis; (3) changes in oceanographic regimes, especially upwelling, which further increase nutrient levels; (4) low abundance of zooplankton and other grazers which eat phytoplankton; (5) less turbulent weather and sea surface conditions; and (6) generally favourable combinations of water quality parameters such as salinity, temperature, and dissolved gases. The spring 4.14

bloom is typically the largest in the year, while the fall bloom is obviously larger than summer levels but is not as large as spring. Winter population densities are lowest. Different species or groups of species dominate the phytoplankton blooms, depending upon the season, water conditions, and successional stages in the blooms.

In addition to this general pattern, there are occasional "red tides" which are phytoplankton blooms, usually of one species. Red tides are unpredictable in time or space. They may cover large areas, but more often they occur in bays, lagoons or other protected waterways (but there are numerous exceptions). Red tides can be so dense that visibility approaches zero even at the water surface.

Zooplankton populations may increase to very high densities and essentially "bloom", but typically the density (either number of 3 individuals, or biomass/m ) does not approach that of phytoplankton. Occasionally copepod, mysids, euphausids, and other zooplankton will "swarm" to the extent that visibility is reduced to centimetres.

Zooplankton blooms follow, and are the main reason for the decline in the spring and fall phytoplankton blooms. Zooplankton populations are typically largest in the summer, and during this time they graze the phyto- plankton population down to relatively low levels. Toward the end of summer zooplankton begin to (1) settle out, if they are larval benthic forms, (2) grow too large to feed on phytoplankton, if they are fish, or (3) reproduce and die off. This relieves the grazing pressure on phytoplankton which can then undergo another bloom in the fall.

4.5. DETAILED EXAMINATION OF THE GREAT LAKES REGION

The Great Lakes is the only region for which reasonably detailed data are available for all limiting parameters including water clarity. In Section 6.0, the five regions are assessed through an examination of a number of subdivisions within each region. Because of the data base available, a more detailed assessment of the feasibility of employing the 4.15

laser as a hydrographic surveying tool can be completed for the Great Lakes. The following sections examine the critical limiting parameters spatially within each of the ten subdivisions in the Great Lakes (Fig. 6.5 on page 6.35).

- 4.5.1 Subdivision la

The Canadian Shield underlies the entire Canadian portion of the Lake Superior drainage basin. Throughout much of the basin the Shield rocks have a veneer of silty to sandy till. The main exceptions are patches of varved or massive clay and silt, and fine and medium sand, which are associated with river valleys or embayments such as Thunder Bay and Black Bay. The shore is essentially bare bedrock eroded by wave action, except in the Thunder, Black, and Nipigon Bay areas where silty to sandy till, clay and silt are common.

Lake Superior has the lowest concentration of suspended solids, dissolved solids, and organic materials of all the Great Lakes. The biological activity is relatively low and, hence, is not a major contributor to turbidity. A spring plankton bloom adds to the turbidity caused by the inorganics injected by spring freshets. The result is a minimum in the Secchi depths during the spring. Wave energy is at a maximum during the fall, but large Secchi depths during this season indicate that wave action has little or no effect on water clarity.

The generally resistant shoreline and uplands that drain into the region lead to low turbidity in the nearshore water. Nipigon, Black, and Thunder Bays have the lowest mean Secchi depth values, ranging from 2 to 5 metres. The rest of the coastal area has mean Secchi depth values ranging from 4 to 13 metres, with a mean value in the nearshore waters of 8.5 m. Figure 4.4 indicates that the waters of Lake Superior are on the average relatively clear and have a diffuse attenuation coefficient less than the -1 required 0.22 m at the wave length of the laser. 4.16

3.0

cr w 2.0

2 m P.O

z 0.6 LAJ 0 0.4 U- LU 0 0.2 z 0 50.4

Lc 0.2

0.4

0.2

0.4

0.2

400 450 500 550 600 650 700 WAVE LENGTH (nm)

Figure 4.4 Spectral attenuation coefficient for the waters of the Great Lakes (Beeton, 1962). 4.17

Ice generally appears by early December in the sheltered areas of the lake, with a minimum occurring in early to mid March. Ice formation ends sometime during late March to early April but ice may be present in the embayments until the end of April or even early May.

Although the open waters of Lake Superior are generally very clear, the shallow areas are limited to the embayments where suspended material concentrations are high. Therefore, water clarity is expected to be a limiting factor for most of the ice-free season in areas of water depths less than 20 m.

4.5.2 Subdivision lb

This region is almost devoid of shallow areas less than 20 m. The only shallow area of any significance is in eastern Whitefish Bay where the sediments are silt, silty sand, and sand. This region also has a higher concentration of organics than the open parts of Lake Superior.

Although Lake Superior is characterized by very clear water (Fig. 4.4), the shallow area of Whitefish Bay has increased turbidity due to the higher concentrations of inorganics and organics. Like subdivision la, the Secchi depths are at a minimum during spring when inorganics from river runoff and plankton blooms are at a maximum. Wave activity in the fall and at other times resuspends some of the fine bottom material and, along with land-derived material, keeps turbidity at a high level in eastern Whitefish Bay throughout the ice-free season.

Like the western portion of Lake Superior, ice generally appears in early December in the sheltered areas and break-up occurs in April. Again, although the open water of Lake Superior is generally very clear, the shallow areas are limited and experience high concentrations of suspended and dissolved material. Therefore, water clarity is expected to be a limiting factor for most of the ice-free season in areas of water depths less than 20 m. 4.18

4.5.3 Subdivision 2a

The north shore of the North Channel region is bordered by the resistant Canadian Shield. Inorganic concentrations from the minor rivers that flow into the area are minimal, but some of the rivers contribute significant humic concentrations. Biological activity is limited, and, hence, Secchi depths greater than 6.7 m are common, except close to river mouths that inject water with high concentrations of humics or inorganics.

Wave activity is very limited due to the short fetches. The eastern end experiences the most wave activity, under the influence of the prevailing westerlies that are funneled along the Channel. Very little resuspension of bottom sediments occurs, however, and the eastern end actually has the clearest water of the subdivision. Plankton blooms in May may limit water clarity locally.

The season affected by ice cover extends up to 5 months each year. During the period from June through September or October, however, conditions, are excellent for the potential use of laser hydrographic surveying techniques with the exception of thunderstorms.

4.5.4 Subdivision 2b

Glacial tills occur along the southern shore, while bedrock, till, and glaciolacustrine clay occur along the eastern shore of Georgian Bay. Due to the resistant coastline and the limited fetches, coastal erosion and suspended inorganics are minimal, and Georgian Bay, along with Lake Huron, has some of the clearest water in the Great Lakes (Fig. 4.4).

The concentration of organics in the major portion of nearshore Georgian Bay tends to be low, and Secchi depths are large and comparable to those in the open waters of Lake Superior. The mean Secchi depths range from 8 to 11 m for the eastern shore of Georgian Bay. The one exception is the Honey Harbour area where organic and inorganic concentrations are elevated and Secchi depths are reduced to less than 5 m for most of the year. 4.19

Ice is present for two to five months of the year, and a minor plankton bloom in May may briefly reduce the water clarity. During the period from June to September or October, however, conditions are excellent for the potential use of laser hydrographic surveying techniques except for the Honey Harbour area and with the exception of thunderstorms.

4.5.5 Subdivision 3

The eastern Lake Huron shoreline is comprised in part of a clay plain extending southward from Point Clark to Grand Bend and by a narrow strip of land consisting of sand and cobble bars and sand dunes. This latter section of shoreline includes the area south of Grand Bend and the area north of Point Clark to the bedrock outcropping of the Bruce Peninsula. This eastern shore of Lake Huron is exposed to waves generated by winds from the north-northwest, the direction of the maximum fetch of over 300 km. The glaciolacustrine cliffs, composed of up to 50 percent clay with varying amounts of silt, sand, and gravel, have been receding at rates between 0.5 and 2 m per year. The regions of sand and cobble bars and sand dunes have been retreating at rates less than 0.5 m per year.

The orientation of the mainland shoreline with respect to the prevailing winds and the fetch lengths, the composition of the shore bluffs and the trend of increasing organics toward the south account for an observed north to south increase in turbidity. Figure 4.5 displays the north-south and onshore increase in turbidity in Lake Huron. Seasonal variation in wind and wave energy account for increased turbidity during the spring and fall when the entire mainland coastline may at times have Secchi depths less than 3 m. On the average, the southern half of the mainland coast will not have water clarity that would permit the use of the laser, but the northern half and the southern Manitoulin coast would.

Ice begins to form along the eastern shore in mid-December, reaches maximum cover during mid-March, and disappears by mid-April, except for the southeastern portion where ice has been pushed by the wind and persists for longer periods. During the period from June to September or October, 4.20

Figure 4.5 Secchi depths (m) for Lake Huron (a) June 1954, (b) July 1954, (c) August 1954 (Ayers, et al., 1956) 4.21

conditions along the Bruce Peninsula coast and southern Manitoulin Island are good for the potential use of laser hydrographic surveying. Turbidity or ice in the southern Lake Huron area would limit the technique year round.

4.5.6 Subdivision 4

Secchi depths for Lake St. Clair are generally less than 2 m. The shallow nature of the lake, especially on the Canadian side, probably results in the resuspension of bottom sediments by wind-generated waves. Organic turbidity, municipal and industrial effluents, and the suspended solids load of the St. Clair River, which is largely derived from shore erosion in southern Lake Huron, also contribute to the low Secchi depth values. Hence, turbidity or ice limits the laser hydrographic surveying technique at all times.

4.5.7 Subdivision 5a

Bluffs are common in the western portion of Lake Erie but are not as high as those further to the east. The bluffs range from about 20 m in height east of Point Pelee, to less than 7.5 m, west of Point Pelee with some low marshy areas in the extreme west. Bluff recession rates range up to 2 m per year.

Figure 4.4 shows that the waters of Lake Erie are the most turbid of all the Great Lakes. Lake sediment resuspension, tributary inflows which are high in suspended solids, and suspended organics resulting from phytoplankton growth contribute to the low Secchi depths and transparencies observed in the shallow western end of the lake (Figs. 4.6, 4.7 and 4.8). The figures indicate a seasonal variation in the water clarity, but, as Figure 4.9 shows, the transparency always remains below the 50 percent value required for successful laser hydrographic surveying to 20 m.

Ice cover is present from. mid-December to mid-March. Turbidity and ice-cover limit the use of the laser hydrographic surveying technique year- round in western Lake Erie. 4.22

Jo

• • • 0 1 — ____•.-..._ --7' . _. • / ..„ CONTOUR INTERVAL . 10 IL „„___,,:i Nerpoo•pe NoNo••••A7 .1101•• • • to CO •• I r

VOW, L•e•uon • I B • • • •

Figure 4.6 Water transparency (percent per metre) in Lake Erie (a) July 15-30, 1965, (b) August 9-20, 1965 (Pinsak, 1968). 4.23

Figure 4.7 Water transparency (percent per metre) in Lake Erie (a) August 31 to September 10, 1965, (b) September 14-22, 1965 (Pinsak, 1968). 4.24

Stenen Location •

—7—

r /

5 z-1.4

zo •

•

1•111•1111 Local*. •

— - -

Figure 4.8 Water transparency (percent per metre) in Lake Erie (a) October 11-26, 1965, (b) October 26 to November 9, 1965 (Pinsak, 1968). 4.25

60 >- Z 50 W cr H0 40 S Z cr 1— 30 .94 La 64 II 20 Z W U CC 10 a_W

JULY AUG SE PT OCT I NOV

Figure 4.9 Average water transparency (percent per metre) in Lake Erie during 1965 (Pinsak, 1968). 4.26

4.5.8 Subdivision 5b

The shoreline of eastern Lake Erie is characterized by resistant limestone headlands with accumulations of sand between adjacent headlands. The shoreline of the central portion of Lake Erie is composed of steep, dissected bluffs composed of two till sheets, overlain with lacustrine silt and sand. Bluff heights in some sections are in excess of 40 m. Bluff recession rates in the central region range up to more than 2 m per year but are much less in the localized eroding portions of the coast in the east. The bluffs contain 50 to 80 percent silts and clays with the remainder sands.

The nearshore turbidity is generally highest in the fall, which is the season of highest wave activity, and lowest in the summer or spring (Figs. 4.6 to 4.8). Maximum mean nearshore Secchi depths range between 4 to 5 m in the spring and summer, whereas, in the fall, the means drop to less than 2 m.

Although it is common for considerable open water to be present, as much as 95 percent ice cover has been observed during some winters. By the latter part of March, much of the ice has disappeared, but ice may remain in the extreme eastern end of the lake as late as the third or fourth week of May.

Turbidity and ice limit the use of the laser technique year round in eastern Lake Erie.

4.5.9 Subdivision 6a

The shoreline and upland areas that drain into the western Lake Ontario subdivision are composed predominantly of clay and till plains. It is estimated that 50 percent of the fine-grained sediment input to Lake Ontario is from bluff erosion (Kemp and Dell, 1975). Bluff recession rates range from 0.5 m per year to more than 2.0 m per year with the height of the shore bluffs varying between 3 and 107 m. The reaches with the highest erosion rates are between Hamilton and Niagara and in numerous locations east of Toronto. 4.27

Figure 4.4 indicates that, next to Lake Erie, Lake Ontario has the most turbid waters. Maximum turbidity occurs in August, indicating a strong relationship between turbidity and productivity and only a slight relationship between wave energy plus bluff erosion and turbidity. Secchi depths range from minimum values of 0.1 m, in the west, to 2 m, in the east, to maximum values of 12 m, in the west to 6 m, in the east. The mean values range between 1.5 and 4.8 m. Maximum values occur in the spring and fall.

The region is usually ice free. Ice that does occur is restricted to the eastern end and is less than 10 percent of the area.

Turbidity is a limiting factor year round for the potential use of the laser hydrographic surveying technique.

4.5.10 Subdivision 6b

The shoreline and upland areas that drain into the subdivision are composed primarily of clay, sand, limestone, and till plains. It is estimated that approximately 50 percent of the fine-grained sediment input to Lake Ontario is from bluff erosion (Kemp and Dell, 1975). Numerous locations along the coast of Prince Edward County, which are exposed to waves from the west, the prevailing wind direction, have significant bluff erosion rates that contribute to nearshore turbidity. The turbidity of the Bay of Quinte area is affected more by river-borne sediment inputs and suspended organics than by bluff erosion.

The Bay of Quinte area has a mean Secchi depth less than 2 m with the lowest values occurring in the spring and summer when suspended organics are at a maximum. In the open part of eastern Lake Ontario, the Secchi depths range from 2 to 6 m in the nearshore waters with the maximum occurring in the fall.

Ice formation in the Bay of Quinte begins as early as mid-December with freeze-up usually occurring sometime during January. Complete ice cover is normal until the middle of March. 4.28

Turbidity and ice are limiting factors year round for the potential use of the laser hydrographic surveying technique.

4.6 MEASUREMENT OF WATER CLARITY

Since water clarity is such an important limiting factor in the successful use of the laser as a hydrographic surveying tool and the data base for turbidity in many areas is sparse, it may be necessary to determine the water clarity in an area prior to implementing the technique. There are a number of levels of effort that can be expended on the task; each with an associated level of accuracy.

As noted in Section 4.3.2, the relevant optical parameter is a measure of the attenuation of light of 532 nm wave length as it propagates from the surface to the bottom through the water column. This is the diffuse attenuation coefficient or the vertical extinction coefficient for the particular wave length.

The coefficient can best be determined by lowering , through the water column a photometer fitted with an appropriate filter to pass light of a narrow band centred on the 532 nm wavelength only. The photometer will observe the attenuation of the relevant wave length band in the sun's radiation spectrum.

A second, less accurate, technique would be to observe the Secchi depth. This method is broad band in nature since it measures the attenuation of the entire spectrum of the sun's radiation and is not limited to the specific wave length of the laser.

Both of these methods require a boat or a floatplane on the water surface to act as a sampling platform and, hence, are expensive and logistically impractical for isolated locations. The alternative is to use aerial photography or satellite imagery. Colour aerial photographs can be 4.29

used to obtain an estimate of the attenuation coefficient from the colour of the water. The correlation between the two parameters is not exact because water colour can be affected in the same way by different combinations of dissolved or suspended organic or inorganic material. Multispectral satellite imagery can also be used to determine the suspended sediment concentration and, hence, an estimate of the attenuation coefficient.

Early attempts at interpretation of remotely sensed images were highly qualitative but more recent techniques are quantitative (Clarke and Ewing, 1974; Thorburn, 1974; Gierloff-Emden, 1976). The accuracy of remote sensing techniques is improved by ground truthing, but satisfactory estimates can be obtained in the absence of ground observations. Although remote sensing provides excellent spatial coverage of the parameter, only a very thin surface layer is measured; hence, it is not the best method to determine the vertical extinction coefficient.

.9 0 3d0 0Vd H 101 1: S - NOLLV 1V IA13 N O 5.0 OPERATIONAL FACTORS - FLYING

5.1 INTRODUCTION

For this study, the aircraft is assumed to be a DC-3, which has a range in the order of 3,500 km and requires a take-off runway in the order of 750 m. The aircraft operational data (Table 5.1) are important in defining whether or not a survey can be carried out from a suitable airfield and the length of time available to conduct a field survey from a given landing and refuelling base.

As is the case with the laser operations, some of the parameters are permanent over a period of years, for example, the location of airfields, whereas other elements, such as meteorological parameters may vary seasonally but, nevertheless, are unpredictable over short periods of time (weeks and months). The flying conditions in which the aircraft can act as a suitable vehicle for the laser system are related to the ability to provide (a) location accuracy, (b) a stable platform, and (c) safety for the crew and operators.

5.2 SURVEY LOGISTICS

Take-off and landing requirements for a DC-3 include factors such as runway length, type of runway, and runway condition. Superimposed on these factors are the cruise range of the aircraft, distance to survey area, and the availability of fuel at the airfield. For this study, it was assumed that a minimum time over the survey area would be one hour, with a three-hour travelling time each way (i.e., 850 km each way) from the airfield. In this situation, all areas in Canada's coastal waters could be reached from existing suitable fields. This assessment did not include the availability of fuel at these existing airfields, which may be a limiting factor in arctic regions. It was assumed that fuel for a survey could be 5.2

Table 5.1 Factors That Affect Flight Operations

(a) Survey Logistics

• runway length, runway surface, runway condition • aircraft cruise range (fuel capacity) • distance to survey area • fuel availability • length of daylight

(b) Flight Conditions (aircraft operations, location accuracy and stable platform)

• Visual or Instrument Flight Rules • visibility - fog, low cloud, heavy rain, snow, hail, and white-outs • availability and distance to alternate airfield(s) • turbulence and cross-winds

(c) Flight Safety

• visibility • thunderstorms, heavy turbulence • icing conditions • migrating birds 5.3

arranged. On this assumption distance from the field site was determined not to be a limiting operational factor, although this does affect the amount of time the aircraft can remain in the study area.

5.3 FLIGHT CONDITIONS

Meteorological factors closely affect (i) the ability to accurately locate flight lines, (ii) platform stability, and (iii) flight safety. Surveys would be conducted under VFR (Visual Flight Rules) conditions which vary geographically but usually require a ground visibility of one mile (1.6 km) and a ceiling of 500 feet (150 m). Runway conditions, such as snow or ice, and the availability of alternate landing sites within aircraft range may limit safe operations, particularly in arctic and subarctic regions.

Visibility is a major parameter from the viewpoint of flying operations as this limits survey accuracy in the study area as well as affecting safe flight conditions at the airfield. If unsuitable visibility exists either in the study area or at the airfield, operations would be curtailed. If the aircraft has IFR (Instrument Flight Rules) equipment, this would allow the aircraft to leave and return to an airport if the study area were clear. Factors that affect visibility are fog, low cloud, heavy rain, snow, hail, and white-outs.

Daylight hours, as defined within VFR, exist one half-hour before sunrise and one half-hour after sunset. "Civil Twilight" is accurately defined as ending or beginning when the centre of the sun's disc passes through 6 ° below the horizon. For this study, it was assumed that a minimum of four hours daylight would be required for a survey. On this basis, from graphs that present the Beginning and End of Civil Twilight on the shortest day of the year (21st December), there would be approximately four hours of legal daylight at latitude 70 ° N. Therefore, all areas of Canada have at least four hours of daylight each day of the year and daylight is not a limiting factor, although the quality of the daylight can be affected by meteorological conditions (i.e., visibility). 5.4

An analysis conducted for the southern Beaufort Sea area (Fig.5.1) summarizes the probability of success for aircraft missions in terms of air-to-ground visibility from different altitudes and in terms of Visual Flight Rules at three airfields.

The ability of the aircraft to provide a stable platform for the instruments is affected by strong winds and turbulence. During periods of strong cross-winds it may be difficult or not possible to maintain a required flight track. Available information sources are not adequate to determine turbulence parameters, either in space or time, but thunderstorm frequency data is available (Fig. 5.2) and is included in the regional analysis.

5.4 FLIGHT SAFETY

Flight safety is affected by a number of operational and meteorological parameters. Visibility and the availability of alternate landing areas within range are obvious factors. Others that must be considered include dangerous meteorological conditions such as strong winds, turbulence, or icing conditions, as well as mechanical difficulties related to cold temperatures.

Bird strikes can present a flight hazard at low altitudes. Large flocks of migrating birds, several 100,000's or more, are common in spring and autumn and may extend over several kilometres. Migration routes and timing are reasonably well known and, where applicable, the information is included in the regional analyses.

5.5

100 100

90 90 HIGH.LEVEL MEDIUM.LEVEL 80 OPTICAL OPTICAL RECONNAISSANCE: RECONNAISSANCE:

70 ABOVE CLOUDS SS % 70 BELOW 300 ro. ESS %

60 CCE 60 UCC F SU F S 50 50 TY O I ITY O 40 40 IL

AB 30 30 BABIL

20 PRO 20 PROB

10 10

0 0 Sep Oct Noy Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jut Aug

100 I 1 1 I 1 100

90 90 LOW.LEVEL 80 OPTICAL 80 RECONNAISSANCE: %

70 SS SS % BROW ISO m. 70 CCE CCE 60 60 SU SU 50 50 OF OF TY ITY I 40 40 IL 30 30

20 20 PROBAB PROBABIL

10 10

0 0 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug

100 SACHS HARBOUR

90 . INUVIK ,- - CAPE PARRY 80

cr) to 70

60

50 O

40

.1 30 0 EE 20

10

0 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug

Figure 5.1 Probability of the success of airborne missions

in the southern Beaufort Sea (from Ross et al. . , 1977). ARCTIC OCEAN

NORTH ATLANTIC OCEAN Labrador Sea

J

Figure 5.2 Mean number of days/year with thunderstorm activity.

NO 110110 0 1:11 N1 1:9 6.0 REGIONAL ANALYSIS

6.1 INTRODUCTION

The primary objective of this study is to evaluate how much of Canada's coastal waters could be potentially surveyed by the laser system with present technology. The factors that limit either the operation or accuracy of the equipment are described in Sections 4.0 and 5.0. The parameters have been analyzed in this study initially in terms of the spatial distribution. Secondly, the analysis considered the frequency of the parameter on a monthly basis in order to provide an estimate of the time periods for which the factor could limit laser bathymetry.

6.1.1 Parameters Analyzed

The study was conducted on the basis of available data. For the most part the information sources that were used were summary documents rather than original data sets. For example, meteorological data (wind, fog, precipitation) and ice cover information were obtained from long-term means.

In order to reduce the level of effort, those factors that would permanently limit the use of the system were considered first. These three parameters were:

• water depth <20 m • (mean) sea-ice cover present <11 months/year • survey area <3 hrs flight time from suitable airfield.

The second item resulted in the exclusion from the study of part of the Queen Elizabeth Islands in the Arctic Archipelago. The third parameter was found to be non-limiting. 6.2

For those areas with water depths <20 m and an ice cover of <11 months, the secondary parameters that were evaluated for each of the 54 subdivisions are listed in Table 6.1.

The three primary parameters would limit the implementation of a laser survey at any time of the year for a particular site and are therefore considered to be permanent limitations with present technology. All of the secondary parameters have a temporal component and may, therefore, be limiting for some part of the year.

A focal point of the analysis was to determine not only where the laser bathymetry system could be used, but also when it would not be limited by the various environmental parameters. The presentation of the data is in two forms: maps of the distribution of potentially feasible areas (Section 6.1.2) and tables that define the frequency of occurrence of the secondary parameters (Section 6.1.3).

6.1.2 Spatial Analysis

The detailed parameter analysis was based on a subdivision of Canadian coastal waters into five primary regions (Fig. 6.1): • Pacific Coast • Great Lakes • Atlantic Coast • Hudson Bay/Labrador Coast • Arctic Coasts

Within each region, a further division was developed that enabled a detailed analysis of individual parameters within relatively homogeneous subdivisions. As there exist considerable variations between biologic, geologic, meteorologic, and oceanographic parameters in some regions, this subdivision must be considered to have been subjective and was designed for the purposes of this study alone. In some instances, because of the variations between the environmental parameters, a subdivision was developed simply for convenience rather than because of an environmental boundary. The subdivisions are based, in most cases, on a regional analysis for Canada's Coasts presented by Owens (1977). A total of 54 subdivisions were identified for this analytical phase of the study. 6.3

Table 6.1 Primary and Secondary Parameters that Limit Laser Bathymetry

PARAMETER EQUIPMENT FLIGHT LIMITING LIMITING

PRIMARY (permanent)

Water depth (>20 m) • Ice cover (>11 mo) • Distance from airfield (>3 hr) •

SECONDARY (temporary) •

Biota - bird migration - kelp • - plankton •

Ice-Cover (>1/10)

Precipitation - rain •

- snow

Visibility (<1 km) •

Water Clarity • -1 Wind - calm (<1 m s )

- strong (>10 m s -L ) • - thunderstorms ARCTIC OCEAN

Beaufort Sea Baffin Bay

Foxe Basin

NORTH ATLANTIC CA OCEAN Lahrador HUDSON Sea BA Y

Lawrence

U N T ED STATES

Figure 6.1 Canadian coastal regions. Areas with solid shading are considered to be suitable for laser bathymetry at some time during the year. 6.5

The scale of the available information varied from area to area. For example, water depths were obtained at a scale of 1:250,000 for most of the Pacific Coast area, between 1:400,000 and 1;600,000 in the Great Lakes, and between 1:200,000 and 1:350,000 on the Atlantic coast. By contrast, in the Hudson Bay-James Bay and Foxe Basin area, a scale of 1:1,000,000 was used. Most of the Arctic was analyzed from 1:500,000 charts, but, in many sections of this region, the data base is either sparse or absent.

A scale factor for practical field surveys was assumed to be 1 km from the shoreline. Only where the 20-m depth contour was located beyond 1 km was the area mapped. This assumption was made to prevent a bias that would reduce the value of the analysis. All coasts have adjacent water depths less than 20 m, but only where they are sufficiently extensive, in terms of a practical flight pattern, is the area considered feasible as a potential survey site.

The spatial summary is presented on maps, in the text of the following sections and on larger maps that accompany this report, in terms of areas where a laser survey could be conducted for at least some part of the year. These maps essentially define the three primary or permanent limitations (Table 6.1), as well as further identifying those areas where water clarity would limit the laser operation on a year round basis.

6.1.3 Temporal Analysis

An approach was developed by which information could reflect (a) the number of months each year, and (b) the days within each month that the secondary or temporal environmental factors may limit the laser equipment or flight operations.

The approach chosen is essentially a matrix of the parameters and months of the year (Fig.6.2). If the parameter would not be a limiting factor for a particular month then that box is blank. This indicates that, base on a regional survey and'on long-term average data, a field survey 6.6

Region Total nearshore area c 20m depth: km 2 (>1km from shore)

J FMA MJ J A SONO

BIOTA kelp beds plankton bloom

ICE COVER .1/10th (mean)

PRECIPITATION rain snow

VISIBILITY

4 1 k m

WATER CLARITY

WIND < 2 knots

> 20 knots thunderstorms

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1111 1 II I I I I I I II II I II II III II II IrZeZ/Z,

Extrapolated data IIIIIIIIillllllllillllllllllll //////,

Interpreted data I inimum 11111 I I 1 I I 1.1:////M4 1=11.11.

Not applicable due to ice cover: * * * *

Figure 6.2 Data format for presentation of Secondary Parameters. 6.7

would not be limited by the environmental parameter. Where the box contains one of the four patterns (open : vertical : diagonal : solid) the factor would be likely to limit a field survey for at least one day within that month. The frequencies used are designed to be interpreted as follows:

1 - 6% limiting for 1 to 2 days each month 7 - 33 limiting for 2 to 10 days each month 34 - 66 limiting for 10 to 20 days each month 67+ limiting for >20 days each month

It must be emphasized that the data base is regional in character and uses long-term averages. Thus, in arctic areas, the limits of a sea-ice cover of one-tenth or greater vary considerably between "good" and "bad" ice years. In order to minimize the potential complexities that would have been introduced by the use of extreme maxima and minima, or mean maxima and minima, the information given reflects mean or long-term average conditions. The focus of this study is on the geographic evaluation of the feasibility of the bathymetric survey system rather than on the provision of logistical or environmental data for the planning of a field operation. The use of means and averages is intended to provide an estimate of the presence or absence of a limiting parameter, rather than an accurate prediction of frequency of occurrence.

In areas where an ice cover exists for some part of the year, the mean minimum ice conditions have been used to define the length of the year during which a field survey could be conducted. For the ice-limited period, the parameters have not been plotted, as the assumption is made that no field surveys would be possible during those months.

The results of the analysis of the secondary parameters have been collated on tables for each of the 54 geographical subdivisions. These tables are presented and discussed in the relevant sections of 6.2 through 6.6. 6.8

6.1.4 Reliability of Information and Data Sources

The parameters that were investigated for this study vary considerably in time and space, both at small and large scales. The data base also varies considerably in quality and detail. In some instances, no data are available for a particular parameter or may be available for only part of a year from a once-only survey. In order that reliability of the temporal information could be shown on the tables, the horizontal patterns are bounded by either solid, dash or dot lines that indicate the source of the information (Fig. 6.2).

Published data is that which is available for an area either from long-term data sets or from multi-year surveys. Extrapolated data refers to regions where it was necessary to extend the published data away from the source area. For example, wind data for a particular meteorological station was, for the purposes of this study, considered to be applicable up to a 200 km radius from that station. Data for areas that lie beyond the 200 km radii of stations were extrapolated. Interpreted data refers to areas where little or no published information exists and where it is not possible to extrapolate from adjacent areas. In such cases a judgement was made based upon a knowledge of the area and of environmental processes.

Meteorological and ice-cover information is reliable and sufficiently detailed for most areas. Data on water clarity, the most critical secondary parameter, and on biota are scarce for all regions; and even where information is available, it is usually restricted both geographically and in time.

The following references were the primary data or information sources used for this study: • water depth

published Canadian Hydrographic Survey charts

biota

Bursa (1961a) (1961b) Fish and Johnson (1937) Jamart et al (1977) Parsons et al (1981) Raymont (1963) Shih et al (1971)

• ice cover

Baily and Grainger (1977) Canadian Hydrographic Service (1979) Fenco (1978) Great Lakes Basin Commission (1976) Markham (1980) (1981) Transport Canada (1964) (undated) (undated)

• precipitation

Atmospheric Environment Service (1982a) Canadian Hydrographic Service (1974) (1979) Great Lakes Basin Commission (1976) Kendrew and Kerr (1955) Phillips and McCulloch (1975) Thomson (1981)

• visibility

Canadian Hydrographic Service (1974) (1979) Hemmenick (1971) Phillips and McCulloch (1972) Transport Canada (1970)

• water clarity

Environment Canada (1980) Frederick (1970) Gibbs (1974) Great Lakes Basin Commission (1976) Gregor and Ongley (1978) Manheim and Meade (1970) Fisheries Res. Brd., Canada, 1955-1975

• wind

Atmospheric Environment Service (1982a) Bailey and Grainger (1977) Canadian Hydrographic Service (1974) (1977a) Fenco (1978) Great Lakes Basin Commission (1975) Kendrew and Kerr (1953) Meteorological Branch (1968) Phillips and McCulloch (1972) Richardson and Phillips (1970) Thompson (1981) Transport Canada (1970)

• bird migrations

Energy, Mines and Resources (1982) 1SVO 3 Old 1 0Vd Z •9 6.10

6.2 PACIFIC COAST

6.2.1 Logistics

All coastal areas are within the minimum transit time of three hours to a study area from a suitable airfield, assuming an aircraft fuel capacity of 8 hours plus reserve. Most sections of this region would be within a one to two hour one-way transit from an airfield with fuel supplies.

6.2.2 Physical Geology

The west coast of Canada is part of the Cordilleran mountain system on the leading edge of the North American plate and is characterized by a narrow continental shelf and high backshore relief. The regional physiography of the coastal area has three main units:

• an outer mountain chain, through Vancouver Island and on the west coast of the Queen Charlotte Islands,

• the mainland Coast Mountains,

• a structural depression that separates the two parallel mountain chains which now contains the Strait of Georgia, Queen Charlotte Strait and Hecate Strait water bodies.

Coastal relief is high everywhere except along the Hecate Strait-Georgia Strait depression. In the areas of high relief, fjords are the dominant coastal landform and nearshore slopes are generally steep. In the fjord environments, the only areas of shallow waters are associated with the fjord-head deltas. These many small deltas would have high sediment runoff in spring months and, therefore, turbid nearshore waters.

Two major deltas, the Fraser and Skeena, have extensive shoal areas, but the high year-round sediment concentrations at the mouths of these rivers result in very low water clarity. 6.11

Some lowland areas are found on the east coasts of Vancouver Island and Graham Island. The most extensive nearshore area with depths <20 m is in the region of northeast Graham Island (subdivision 5: Table 6.2) where glacial sediments have been eroded leaving a wide sand-covered shore (Dogfish Bank and McIntyre Bay). Elsewhere, areas with shallow waters are _ scattered and limited in extent (Fig. 6.3).

The total area of the shelf with water depths less than 200 metres 2 2 is in the order of 77,000 km , of which only approximately 11% (8,500 km ) has water depths less than 20 m (Table 6.2). One third of the shallow areas occur within subdivision of northeast Graham Island. The combination of the Queen Charlotte Strait-Hecate Strait subdivision with northeast Graham Island accounts for two thirds of the total shallow areas.

6.2.3 Oceanography

On the exposed coasts, offshore wave heights are greater than 3 m for 30 percent of the time in winter months, but for only 5 percent of the time in summer months. Most of the wave energy on the outer coast is in the form of long-period (up to 15 s) swell waves from the west. In the sheltered coastal waters of Hecate Strait and the Strait of Georgia, waves are generated by local winds that predominantly parallel these water bodies. Again, an increased frequency of winter storms introduces a seasonal variation in wave heights with waves greater than 3 m occurring 10 percent of the time in winter and less than 5 percent of the time in summer. The wave climate along the coastline varies geographically depending upon fetch distances and orientation.

Ice plays a very minor, almost negligible, role in the oceanography of the Canadian Pacific coast. Seawater temperatures are always above freezing, and ice only forms in sheltered inlets where freshwater runoff dilutes the seawater and freezes.

The mean tidal range decreases from approximately 5 m in the northern coastal areas to a minimum of 2 m at Victoria. The tide is semi-diurnal and large tidal ranges are approximately 50 percent greater than the mean ranges. Table 6.2 Pacific Coast - Bathymetric Areas (subdivision boundaries are given on Fig. 6.3)

Subdivision Area with Depths <20 m (km')

1 363 2 671 3 1,136 4 2,436 5 3,075 6 519 7 356

Total 8,556 6.13

ALASKA

0 50 100 150 I■1==i Km

Figure 6.3 Pacific Coast subdivisions. Areas with a solid shading are suitable for laser bathymetry; cross-hatch areas have water depths <20 m but are unsuitable due to poor water clarity. 6.14

The water clarity for the most part is excellent. The clarity is degraded seasonally by plankton blooms, which peak in the early summer, and locally by freshwater runoff, which is high in suspended sediment concentrations. The Fraser (Fig. 6.4) and Skeena Rivers have very large, turbid plumes that affect a large area of the surrounding coastline. Many of the rivers flowing into the heads of the coastal inlets are laden with glacial flour scoured from the glaciated headwaters. Spring freshets, in particular, inject large plumes of relatively fresh, turbid waters into the surrounding coastal areas.

The rocky sections of the coast are frequently characterized by extensive kelp beds. This vegetation is seasonal in nature with growth commencing in March and storms tearing it loose in October- November.

6.2.4 Meteorology

There exists a distinct seasonal variation in wind and precipitation patterns due to the passage of low pressure systems through the region in winter months. Wind velocities and precipitation levels are higher from October to March. Visibility can be a factor on the southern mainland coast in summer and elsewhere during winter months.

Locally, funnelling of winds and turbulence are common on many sections of the coast due to the presence of fjords and to high relief respectively. Thunderstorms are rarely a factor of the local climate and substantially less important than winter cyclonic storms that may pass across the region with a frequency of up to one every three or four days.

Fog is a factor but is not considered of major importance, and it is rare for it to limit flight operations for more then a few days in any month. The frequency of fog is highest in summer and fall months, due to the difference in temperature between land and sea and to the lower wind velocities at those times of the year. 6.15

Figure 6.4 Composite distribution of the Fraser River sediment plume (Duffus, 1979). 6.16

6.2.5 Regional Analysis and Summary of Limiting Factors

The following tables summarize the results of the analysis in terms of the temporal variations in the limiting factors for each of the seven subdivisions of the Pacific Coast region. The spatial distribution of the depths less than 20 m is given on Figure 6.3 and on the 1:1,250,000 map that accompanies this report; the data are summarized in Table 6.2. The only extensive shoal area is the northeast coast of Graham Island. Elsewhere depths less then 20 m tend to be small in area and scattered.

Ice is rarely a factor, but may occur during periods of cold temperatures in sheltered inlets and bays. Much more significant locally are the inputs of suspended sediments to nearshore waters by large rivers and the growth of kelp beds on shallow rocky substrates. Plankton blooms commonly occur during the summer and can significantly affect local water clarity. Virtually all subtidal rocky substrates will have an anchored vegetation cover. Even though the cover may not be continuous it would likely be sufficient to interrupt survey coverage, particularly during summer months.

There are few large rivers due to the small size of most catchment basins; therefore water clarity is generally adequate adjacent to river mouths except during the spring freshet. The exceptions are the Fraser and Skeena Rivers that have high sediment loads. The Fraser, in particular, has an extensive sediment plume that would virtually preclude laser bathymetry in that region.

Flight operations may be limited by winter storms between 10 to 25 days in a month, depending upon the location of the major pressure belts. In winters when the pressure belts are to the south the cyclonic storms pass over the northwest United States. When the pressure belts are in their usual winter position, or to the north, the systems pass directly over the British Columbia shelf and coastal areas. 6.17

In summary the primary features of the analysis for the Pacific Coast are as follows:

• Few extensive areas exist with depths less than 20 m.

• Where these areas occur, operations may be limited due to rooted kelp if the substrate is rocky, and water clarity may be poor adjacent to small rivers during the spring freshet.

• Plankton blooms may be significant locally during summer months.

• The Fraser and Skeena Deltas have a year-round sediment plume that would prevent use of the system in these areas.

• Flying operations would not be limited significantly by meteorological conditions or by bird migrations, although there may exist some local, short-duration limits.

• Ice is not a significant factor in this region. 2 • An estimated 8,500 km in this region have water depths less than 20 m; of this total, approximately 7,800 km' (90%) could be considered suitable for laser bathymetry. 6.18

PACIFIC COAST Region #1 Subdivision

Primary Limiting Factors:

a relatively small area with depths <20 m associated with the Fraser Delta and Boundary Bay.

Secondary Limiting Factors: suspended sediments from Fraser River would limit water clarity year—round in the delta area,

ice insignificant as a limiting factor,

weather conditions may be a partial limiting factor due to winter cyclonic storms or summer thunderstorms,

major winter bird migrations may affect flight conditions, fog could limit flight operation, especially in October.

Data Base and information Gaps:

good distribution and detail of oceanographic/meteorologic data and of water clarity data. - 6.19 Region PACIFIC Total nearshore area .420m depth - 363 km2 #1 ( > 1 km from shore)

JFMA MJ JASOND

BIOTA Ur II 11 iIIMMENNIWZ, kelp beds 1111111111111111ii 4 LIIE Itillililiiiilllii II ..... • .

plankton bloom 111111111 i ■ OM NM MN 1 III

- --1

ICE COVER I . a 1/10th (mean) •

PRECIPITATION rain "40:1YIZZ/4/1111111111111111111 111111111111111111111111111V74VM snow Offig 1111111111

VISIBILITY 4 1 km 11101111111111111 111111111 111111111 111111111W/11111111 111111111

WATER CLARITY

WIND < 2 knots 1111111111111111111111111111 111111111 1111111 ' R1111111 i11111-1111111111

> 20 knots r,r1/4/%721111111111n 71r1117: 77%2//4, thunderstorms

Other: 1E Ii

BIRDS Milii . 101111117111

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 111111111111111111111111111111/7/ZeZZAIIIIIIIIIIIIIMMI

Interpreted data 1 11111 1111llim inm inntrimm

Not applicable due to ice cover: * * * * 6.20

Region PACIFIC COAST

Subdivision #2

Primary Limiting Factors:

shoal areas are scattered, no large extensive shallow areas.

Secondary Limiting Factors:

kelp and plankton may limit feasibility from May to October,

ice is not significant as a limiting factor, but may occur during cold periods in inlets and bays,

winter cyclonic storms and fog could inhibit flight conditions from September to March,

rivers may have high suspended sediment loads during the period of maximum runoff (spring); this would affect water clarity locally,

water clarity locally poor in spring because of runoff and in summer because of plankton blooms,

bird migrations should be considered as a factor in flight oper- ations from November to March.

Data Base and information Gaps:

good distribution and detail of oceanographic/meteorologic data for this analysis 6.21 Region PACIFIC Total nearshore area c20m depth' 671 km2 #2 ( > 1 km from shore)

JFMA MJ JASOND

BIOTA

f/1//oz/// [ZI I 1 zie Z kelp beds = _2 i IN 1 I ii ■ S l MIN MINIM := • I 1 IN Ma 111•1111 NM NMI MM .IM 2

plankton bloom =1 1 I l . 1 .

11 ...... —

ICE COVER . . a 1 /10th (mean) • ,

PRECIPITATION rain .AellZeZZ,ZZAAA1111111111111111111 snow I111III1 111111111 1= 1= Ii Ii 1m Ii II I.

VISIBILITY I 'I • ■Il SIM ■ IIMMIN I II . I . a ■■■ MIMI :7 RIT17 <1km INM 1

LIIL

WATER CLARITY 1■11111111111 SIM IIMI 1 1 I

. 7- -7 =1 = 11 - ■ II ...... NM MOSS ME a IOW I. ✓ 1■ I 11•11111 MEI IIIIM

WIND - <2 knots J111101011111 1111%11111111

>2 0 knots riv#/#17,11111111111! ...... i , Illnr11P17/11:4(Z..

thunderstorms - II i II i '

Other: ...... .-- -- BIRDS --, -- -- I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data 1 11111111111 1 11111111111 11 111 rzmzezsimm=1

Extrapolated data 111111111111111111111111111111 7/Z/ZZA1111111=11111111IM

Interpreted data

Not applicable due to ice cover: * * * * 6.22

PACIFIC COAST Region #3 Subdivision

Primary Limiting Factors:

numerous nearshore shallow areas, particularly along the northwest coast of Vancouver Island.

Secondary Limiting Factors:

kelp (on rocky areas) and plankton would likely be limiting on water penetration between June and September,

precipitation and winter cyclonic storms (October to April) and fog (June to September) could limit flying operations, rivers/streams would generally have low sediment loads so that water clarity due to inorganic material would be only locally limiting - mostly during period of maximum runoff,

water clarity locally poor in spring because of runoff and in June because of plankton blooms,

ice is rarely a limiting factor,

high waves (>3 m) breaking in shallow waters could limit laser penetration in winter months on exposed coasts.

Data Base and information Gaps:

oceanographic and meteorologic data base adequate for this analysis.

6.23

Region PACIFIC Total nearshore area c 20m depth: 1,136 km 2 #3 (>1km from shore)

JFMA MJ JASOND 1110101

BIOTA . #4111111111111111111

kelp beds 1111011111011111111*/T , -- 1 ' I 1.0 - --

plankton bloom 1 1 Y-17171r l= -

-- --- ICE COVER

I I I a 1/10th (mean) I .

PRECIPITATION rain et//1"7",7,. e. 0 MERV /- snow pun, 111111111 •=1 1 1 1= 'N VISIBILITY 1 -ai - = -a ,, I I l 4 1 km El% 4171577 'eZZITITIj- ,

WATER CLARITY !S

111111111111111111V)77)7A∎ I WZZ11111111r111111111' 1. WIND < 2 knots - >20knots 9777,17777AIRTI rtirirjritilaja0 t???Z, ... 1 ! I 1 thunderstorms ---- ■ ■ ■ In IMMO IIN Ilan ( II 1 I

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1111 111 111111 111 1111111 11 11111///////,

Extrapolated data 1111 11 1111111111 111 1111111111 1//////f 1

Interpreted data 11111111111111111 1 111111111V/Z/Zei

Not applicable due to ice cover: * * * * 6.24

PACIFIC COAST Region

Subdivision #4

Primary Limiting Factors:

numerous scattered nearshore shallow areas, particularly in northern parts of the subdivision.

Secondary Limiting Factors:

kelp (on rocky areas) and plankton would likely be limiting between May and October,

aircraft operations may be limited by winter cyclonic storms (October to April), by summer/fall fog (June to October), or by bird migrations (April:October/November),

water clarity adjacent to large rivers (e.g., Skeena) would be poor, particularly during spring freshet because of high suspended sediment load,

water clarity locally poor in spring (March to May) because of runoff and in summer (June to August) because of plankton,

ice is rarely a significant factor but should be considered in inlets and bays during periods of cold temperatures.

Data Base and information Gaps:

data on oceanographic and meteorologic factors generally adequate for this analysis. 6.25 Region PACIFIC Total nearshore area c 20m depth: 2.436 km 2 #4 ( >1km from shore)

J FMA MJ J4SO ND

BIOTA ✓ ✓ kelp beds PdearZ. re.rtiej...... 11.11 [ 0 VW.A !S Ii uI 1= ILA 1-1 I i MI NM ■ IMM. l M. MOM NM 1U I l - plankton bloom ! 1 ...---. 14■■ MNIONI Mirri=

ICE COVER . . a1/10th (mean) . yu i§! 1\ 11 II MI 1\1 1\ k L IS IN PRECIPITATION o ■ 1 I 1 ! 1 I I _ .

rain ff ri PI 0 I F; 1 I= .A =i I snow I i i -

I ii ! VISIBILITY I i ...... I I 1 k M I 4 rimimmir -- ---

lil iu WATER CLARITY IS! la iEI 1 iIIIIIIIIVI '' - iIIIIIIIIf

T .------

WIND - < 2 knots > 20 knots r#####ZIAM111111111111111111111111J11111111111111EllyZeZZI4

MNMNMI l■ MOI ■• INNIWIM MN NI= MO a --- -- thunderstorms .... -..... - . Li II ii Other: I .....• , Li

BIRDS . ....

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 111111m111111111111111Ermm,

Interpreted data iim m minimmini tiil wm#■■■

Not applicable due to ice cover: * * * *

6.26

Region PACIFIC COAST #5 Subdivision

Primary Limiting Factors:

extensive shoal areas adjacent to the coast (Dogfish Bank and McIntyre Bay).

Secondary Limiting Factors: shoals are predominantly sedimentary material, therefore, kelp is not a limiting factor where sands are present,

water clarity may be affected locally by river runoff and sus- pended sediments in spring (March to May) and by plankton blooms in June,

aircraft operations may be limited by winter cyclonic storms (October to April), summer fog (May to September), or by bird migrations (April: October/November),

ice is not a significant limiting factor.

Data Base and information Gaps:

data on oceanography and meteorology adequate for this study. 6.27

PACIFIC Region Total nearshore area ic 20m depth: 3 , 075 km 2 #5 (>1km from shore)

J FMA MJ JASOND

BIOTA kelp beds tie:fir/4e~ . "zed 1 Ii I — 7 i _ - plankton bloom ----- 11 #/111111111

- . __, ....---• - ICE COVER ■ .... ■ a 1/10th (mean)

PRECIPITATION rain snow 111111111 11111111111111111 IIIIIIIII i 11

VISIBILITY 1 Iiiihdilin I I I 11 1

- . MIN= MEI 1 I 1 i a I 4 1 k m - - ••• MEM

,

WATER CLARITY

111111111 ''' 11117111Fra1lli

WIND <2 knots

>20knots gii.27i21.711-1121MMITERIPlinTrt7) 7 72 --- -- thunderstorms --. -..... I Other: •.• INIM MI

BIRDS I —....

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 rzzzzez zlimmissil

Extrapolated data

Interpreted data 1111111111111111111111111 1 1V.

Not applicable due to ice cover: * * * * PACIFIC COAST Region #6 Subdivision

Primary Limiting Factors:

only a few small scattered areas with depths <20 m.

Secondary Limiting Factors:

kelp would limit the technique on rocky areas (May to October) and plankton would affect water clarity locally in June,

rivers would be unlikely to supply high volumes of suspended sediments even during the freshet,

flight operations would be limited by winter cyclonic storms (September to May), by fog (February to October), or by bird migrations (April: October/November),

ice is rarely a limiting factor except in sheltered inlets and bays.

Data Base and information Gaps:

poor physical data base but adequate for this evaluation. 6.29 Region PACIFIC Total nearshore area c 20m depth: 519 km 2 #6 ( > 1km from shore:

J FMA MJ J A SO ND BIOTA ■

refr /Z.0 ITI r i/7/4 0 Mil I I 1111 ,eZ, /%4 - I

kelp beds - I I I II rs I I i - i A i I

plankton bloom .!

.-- r I I

-...._ - a

7Z -Z. ICE COVER . . . a 1 /10th (mean)

PRECIPITATION rain A lIZZ trAW1Zei Zielr 7,7"1"/". snow 111111111 111111111111111111 111111111 VISIBILITY 4 1 k m 111111111 11111111 11111111 1111111111111111111111111111111111111111111111 r I IN! i1 iI WATER CLARITY , ■ II . I min 1 1 I

/ IMO MO I 1

WIND <2 knots 111111111 11111111111111111 11111111111111111111111111111111111111111111111111111111 111111111 111111111111111111 >20knots 2'274,,A111111110111111111; 111111111 ■##/#4977

im MIN IMP N. III= =I thunderstorms NM ■II III II il■ MM. I I !

Other: ...... •

BIRDS ---- i I I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111111111111111111WM

Extrapolated data 111111111111111111111111111111/MM

Interpreted data 1111111111111 111111 1 1111111V/M.

Not applicable due to ice cover: * * * * Region PACIFIC COAST

Subdivision #7

Primary Limiting Factors: shallow depths <20 m are limited in area and scattered.

Secondary Limiting Factors:

water clarity could be limited locally in June by plankton blooms,

flight operations could be affected by winter cyclonic storms (October to April), fog (year-round), r by bird migrations (April: October/November),

ice is rarely a limiting factor except in sheltered bays or inlets during periods of cold temperatures,

high waves (>3 m) breaking in shallow waters could limit laser penetration during winter months.

Data Base and information Gaps:

poor data base but generally adequate for this evaluation.

6.31

Region PACIFICC Total nearshore area c 20m depth • 856 km 2 #7 ( >1km from shore)

J FMA MJ J A SO ND infiummillormre BIOTA M kelp beds 111111111 1111111111111111111 1 1.7 i i I

1...--- [i

- I plankton bloom : - _,111111 ---- E(122E1171. .

_—

ICE COVER . ?.1 /10th (mean) ,

PRECIPITATION rain ZlItt lZeldr,,,,,,,,,77) snow FM111111111 111111111 1111111111

VISIBILITY 4 1 km 11111111 111111111 111111111 111111111111111U 111111111111111311111111 111111111 TITITITII711711 IL WATER CLARITY II El I . .-11111111::

.

WIND I■ MIMI IMIII III= <2 knots

>20knots azeizezezainiumpiliiiiiiiiiirtiritirER'zif# #.1

- thunderstorms —...- ---

Other: ii II I= =MI OM =MI MI

BIRDS ....--,-..•

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1 11 1111111111111 1 111111111111 VM/M p11111■1

Extrapolated data 1f1111111111111111111111111111 /7#####,

Interpreted data

Not applicable due to ice cover: * * * * S3 )1 V11V3 1:10 E •9 6.33

6.3 GREAT LAKES

6.3.1 Logistics

All coastal areas are within the three hour minimum transit time from a suitable airfield. All parts of the nearshore zone would, in fact, be within only one or two hours from an airfield with fuel supplies.

6.3.2 Physical Geology

The physiography of the Great Lakes region is inherited from the effects of glaciation. River systems were enlarged by ice sheet erosion and glacially eroded sediments were deposited as thick blankets that mantle the bedrock in southern areas. The primary geologic contrast is between shore-zone bedrock outcrops (Lake Superior, Georgian Bay, northern Lake Huron, and northeast Lake Ontario) and coasts of unconsolidated sediments (south and east Lake Huron, Lake St. Clair, Lake Erie, and west and north Lake Ontario).

The Canadian Shield forms the coasts of Lake Superior, northern North Channel and north and east Georgian Bay. These outcrops are largely devoid of sediment cover and the rivers of the region are low in sediment yield.

The coasts to the south of the Shield have bedrock outcrops in areas where resistant outcrops occur, such as the Niagara Escarpment, but the shore zone is characterized primarily by eroding unconsolidated cliffs of sands, silts and clays. Erosion of these cliffs by waves and rivers produces fine-grained sediments in most areas.

Lake Superior has few shallow areas (Table 6.3), and these are in the Thunder Bay and Whitefish Bay areas. By contrast, all of the other lakes have continuous shallow nearshore waters. The most extensive shore areas are in Lakes St. Clair and'Erie (Table 6.4). 6.34

Table 6.3 Great Lakes - Bathymetric Areas (subdivision boundaries are given on Fig. 6.5)

Subdivision Areas with Depths <20 m (km2 )

Lake Superior la 1,210 lb 454

Lake Huron 2a 1,576 2b 2,704 3 2,741

Lake St. Clair 4 661

Lake Erie 5a 3,077 5b 3,883

Lake Ontario 6a 725 6b 1,008

Total 18, 037 ■

Table 6.4 Great Lakes - Summarized Bathymetric Areas

Ilk Area <20 m Coastline Area: Length (km2 ) Length Ratio Lake Superior 1,664 2,380 0.7: 1 Lake Huron 7,021 4,810 1.5: 1 Lake St. Clair 661 135 4.9: 1 Lake Erie 6,960 639 10.9: 1 Lake Ontario 1,733 618 2.8: 1

R 1.95: 1 2a North Channel

Georgian Bay

Lake St. Clair 0 50 100km

Figure 6.5 Great Lakes subdivisions. Areas with solid shading are considered suitable for laser bathymetry; cross-hatch areas have water depths <20m, but are unsuitable due to poor water clarity. 6.36

The area-to-shoreline length ratio for this region is in the order of 2:1 (Table 6.4), whereas the same ratio for the Pacific Coast is 0.3:1. In terms of the water depth parameter alone, the Great Lakes region, with the exception of Lake Superior, would appear initially to be a feasible area for extensive cost-effective, shallow-water bathymetric surveys. Of particular significance is the fact that all of the Lake St. Clair basin falls within the required depth parameter.

6.3.3 Limnology

Fetch distances are limited in the Great Lakes so that wave heights are relatively low (generally <2 m) and wave periods are short (<7 seconds). The significant wave heights vary seasonally with the winds and are lowest during the summer months (usually between 0.1 and 0.6 m) and highest in the winter (between 0.8 and 1.7 m). The wave climate along the shoreline varies geographically depending upon fetch distances and orientation.

Ice is prevalent throughout most of the shallow coastal areas of the lakes during the winter months between mid-December and early April.

The water level in each of the lakes varies continuously annually and from year to year. Short-term fluctuations within a particular lake of the order of tens of centimetres exist due to wind setup, and long-term fluctuations of the order of 0.5 m annually exist as a result of changes in the inflow or outflow.

The water clarity is greatest in Lake Superior and progressively deteriorates in the downstream direction from lake to lake. The increased turbidity is a result of increased suspended sediments in the runoff from the lowlands surrounding the lower lakes and a greater production of plankton seasonally in Lakes Erie and Ontario. (NOTE: More detailed data on the water clarity of the Great Lakes system are given in Section 4.5: pages 4.14 to 4.28). 6.37

6.3.4 Meteorology

The Great Lakes region lies in the path of cyclonic storms that cross the North American continent from southwest to northeast along the Polar Front. The storms are most frequent in winter months, in the order - of one every 4 to 5 days. In summer the frequency and intensity of the low-pressure systems are lower, the region assumes a more continental climate, and convection thunderstorms are common, particularly in the lower lakes.

Flight conditions would potentially be limited in winter by snow and strong winds associated with the movement of the cyclonic storms through the region. In summer months, thunderstorms are most common between July and August and could affect local flight operations. Strong winds and turbulence would generally only be significant during storms, either cyclonic or thunder. Fog and poor visibility are common but not significantly limiting.

6.3.5 Regional Analysis and Summary of Limiting Factors

The temporal variations of each of the limiting factors are presented graphically in the following tables, for each of the ten subdivisions in the Great Lakes region. The distribution of depths less than 20 m is given in Figure 6.5 and the 1: 1,580,000 scale map that accompanies this report. The distribution of depths is summarized in Tables 6.3 and 6.4.

The regional pattern in the Great Lakes system is one of a progressive decrease in water depths from Lake Superior downstream, but with an offsetting increase in suspended sediments that significantly reduces water clarity.

The shallowest lakes (St. Clair, Erie and Ontario) are in a lowland area where the bedrock is mantled by thick glacial deposits. In addition the coast of much of these lakes is characterized by rapidly eroding 6.38

unconsolidated cliffs. The supply of fine-grained sediments from rivers and cliff erosion results in high concentrations of suspended sediments that would largely preclude the use of the laser system in these three lakes. Exceptions occur in time and space, for example, the Thousand Islands region of east Lake Ontario is a more resistant bedrock (shield) outcrop so that sediment inputs from rivers and coastal erosion are considerably lower than in other parts of the lake but water turbidity is still normally quite high.

In the Lake Superior and Georgian Bay region the underlying bedrock is the resistant Shield, and the surficial sediments are either absent or thin. As a result, the coast is predominatly resistant bedrock outcrops and streams supply relatively small amounts of sediments from the catchment areas. The lake waters in this region are therefore usually clear. However, in Lake Superior only a few shoal areas are present. In Georgian 2 Bay-North Channel an estimated 4,300 km of depths less than 20 m could be surveyed, other factors permitting.

Lake Huron is intermediate between the deep, clear upper lakes, and the shallow, turbid lower lakes. In the north, adjacent to Manitoulin Island and the Bruce Peninsula, the waters are relatively clear as this region is similar, in terms of the coastal character and surficial geology to the Shield area. South of the Bruce Peninsula, surficial sediments characterize the shore and backshore zones so that sediment supply from cliff erosion and river runoff increases significantly towards the south of the lake.

2 Although there exists in the order of 18,000 km of shallow waters that could be surveyed with the laser technique, the limitations imposed by fine-grained suspended sediments would preclude use of the technique in the 2 lower lakes. Thus only approximately 8,000 km would be potentially suitable. Of this total, the majority of the shallow areas are in the 2 nothern Lake Huron-Georgian Bay-North Channel area (approx. 6,300 km ).

Operations in areas where water depths and water clarity are suitable would be potentially limited by winter ice (December to April) and 6.39

by plankton blooms (May). Other limiting factors on either the technique or on flight operations may be significant at the local scale, for example, thunderstorms or bird migrations.

In summary, the regional analysis for the Great Lakes indicates:

• A strong relationship between the presence of unconsolidated glacial sediments in the coastal zone and catchment basins with highly turbid waters.

• In the lower lakes, this relationship is a dominant limiting factor that would preclude use of the laser system in Lakes St. Clair, Erie and Ontario areas where there would otherwise exist approximately 10,000 km of waters to which the system could have been applicable.

• The waters of the upper lakes, in the Canadian Shield geological region, have low sediment concentrations due to a thin and discontinuous cover of glacial materials. Few shallow water areas occur in Lake Superior, but a sufficient number exist in Georgian Bay-North Channel to make the laser technique a potentially useful survey method.

• Local limiting factors include plankton blooms in spring and thunderstorms in summer.

• Lake ice would preclude use of the technique between December and April each year. 2 • In this region, an estimated 18,000 km area has water depths less than 20 m; of this total, only an estimated 6,000 km (33%) would be suitable for laser bathymetry due to water clarity limitations during the open-water season.

GREAT LAKES Region

Subdivision

Primary Limiting Factors: relatively small area with shallow depths in northwest sections, particularly in Black Bay and Nipigon Bay.

Secondary Limiting Factors:

ice is present up to 4 months each year,

plankton may affect water clarity locally in May and occasionally during summer months,

although water clarity in Lake Superior is generally excellent, suspended sediments are likely to limit water clarity in the shallow areas of Nipigon, Black, and Thunder Bays,

flight operations may be limited by summer thunderstorms and pre- cipitation(June to October) and by winter snow (December and Jan- uary); bird migrations pass through the area from March to May and September to November.

Data Base and information Gaps: physical oceanography and meteorology data are adequate for this study,

some data available on plankton and water clarity. 6.41 GREAT LAKES Region Total nearshore area ic20m depth: 1,210 km 2 ( > 1 km from shore)

J FMA MJ JASOND

BIOTA kelp beds

- plankton bloom - 71 111111111111111111111111111111111111 111111111 11111111

ICE COVER ICI !N! I t 2.1/1 Oth (mean) I

PRECIPITATION rain 11111111111111111V/Z/ZeZZ,A111111111 111111111 snow Vzinnuitiiiiimmiumi 11111111,/,

VISIBILITY 4 1 k m 1— — =ME= 11EMEETIMMELIT

WATER CLARITY . OP ZZ1v irir 4 Or / # ZAI r

WIND < 2 knots 111111111111111111 111111111 111111111 1111111( 1111111a11111111 111111111 1111111$11111111111111111 111111111 111111111111111111 1111111111111111111111111 111111111 111111111111111111 > 20 knots !EA h I

thunderstorms I IIMM TMTE::::..: Ot er: ! n Uu -- .-- -- in 1 BIRDS . .—. --.. ..-- I I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111 11 1111 1 111111111 1 11111/Z/ZZ/Z 1

Extrapolated data 1111111111111111111111111111110IZIZZZA1111■11

Interpreted data 111111111111111111111111111t111/#/###

Not applicable due to ice cover: * * * *

GREAT LAKES Region //lb Subdivision

Primary. Limiting Factors:

very few areas with depths less than 20 m,

only area of extensive shallow waters is Whitefish Bay; else- where, only a few scattered shoals occur in this subdivision.

Secondary Limiting Factors:

ice is present up to 4 months each year,

plankton may affect water clarity locally during May and occasion- ally in summer months,

although water clarity in Lake Superior is generally excellent, suspended sediments are likely to limit water clarity in the shallow waters of Whitefish Bay,

flight operations could be locally limited in summer by thunder- storms and precipitation (June to September) and in winter by snow (November to February): bird migrations pass through the area in spring (March to May) and fall (September to November).

Data Base and information Gaps:

data on oceanography and meteorology are adequate for this evaluation; some information available on water clarity but none on lake biology. 6.43 454 Region GREAT LAKES Total nearshore area %20m depth: km 2 ( > 1 km from shore) # lb

JFMA MJ JASOND

BIOTA kelp beds

_ plankton bloom - 111111111 111111111 11111111 111111111 111111111

ICE COVER a 1 / 10th (mean) mummurs: iiiTaii

PRECIPITATION rain IIIM mullwAidrummr,KArzze4iimii imiffir

snow rziotefallon ----W77. 1-mr .= 1= I_1 1= 1 VISIBILITY ta

I OM IN= 1=11111•11• 1100 =MI MIN. _ 21 41 km -1 1 1 ...... 1111111111 FIEf , 111111111E111111111111111

10 IS' 1% WATER CLARITY ,...... 7221. IS iq IN ! ; 1 .

WIND < 2 knots 111111111 111111111 11111111111111111111111111111111111 111111111 11111111111111111111111111111111111111111111111

> 20 k nots 111111111 111111111111111111111111111111111111 11111111111111111 1 111111111 I i 1=1 111•111. I ! I !N

I ! I Mr. 7 thunderstorms ID ■■MN. I [TT 1 O ther: I =NI NM MIMS 0 ■ A 1

BIRDS ! I IN■■ • 11•1111.■ A • MM ■I ]

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data 111 111111 11111 11111111111 11111WZM

Extrapolated data 1111111111111111111 111 11111yWM

Interpreted data 111111111111111111111111111111,###/#

Not applicable due to ice cover: * * * * 6.44

GREAT LAKES Region

Subdivision #2a

Primary Limiting Factors:

most of the nearshore waters are shallow, particularly on the north shore of North Channel (rocky Shield coast).

Secondary Limiting Factors: ice is usually present up to 5 months each year,

plankton may affect water clarity locally, particularly during May and occasionally throughout the summer and fall; river runoff is unlikely to reduce water clarity,

thunderstorms and precipitation can affect summer flight oper- ations (June to September), as can snow in December to Febru- ary, and bird migrations in the spring (March to May) and fall (September to November).

Data Base and Information Gaps:

adequate data available on physical oceanography, meteorology, and water clarity,

some data or information relating to plankton, but little on sea-grass. 6.45 Region GREAT LAKES Total nearshore area .420m depth: 1,576 km 2 ( > #2a 1km from shore)

J FMA MJ J A SOND 1 BIOTA kelp beds 1 plankton bloom .. 1111111111=1I11111111111111111 111111111 Il1111111111111111111111111 PII ICE COVER

a 1/10th (mean) _---- - P774 ,

PRECIPITATION I rain mimmiuniiiimummuni111111111iiiimitezzeinumemnint snow re#40teA1111111111111111111 111111111,10

VISIBILITY 4 1 km JIZIZZIV mum nionanipiimi milllommition

WATER CLARITY 1111111111.11111111111111t11111111111111111111111 111111111 11111111' [ I 1 I ! I =P 1 i 1 77

WIND 9 P I 4 7. i < 2 knots 1 j 1 1111111111 kiMillilRii iiii1111 I I= •__ -if I Ig 1

F-- E E - - - - 1 I I

1 1 ! ! > 20 knots 07 _d . ---. [ I I thunderstorms 1111111111 111111111 111111111111111111 1 1 II Ii ii II I ..g.,.. Other: 0 ■I IN= I

BIRDS I I ...... --, I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 11111111111111111111111 111111 1/MM

Interpreted data

Not applicable due to ice cover: * * * *

GREAT LAKES Region

Subdivision #2b

Primary Limiting Factors:

extensive and continuous shoal depths along the Shield coast of Georgian Bay.

Secondary Limiting Factors: ice is present between 2 and 4 months each year,

water clarity is unlikely to be affected on a large scale by river runoff, but may be locally limited by plankton in May and occasionally throughout the summer and fall,

flight operations may be limited by thunderstorms in summer (June to September) and by snow in December to February,

bird migrations pass through the area in spring (March to May) and fall (September to November).

Data Base and information Gaps:

data base generally adequate for this study, except for infor- mation on biological parameters. 6.47 2.704 km 2 Region GREAT LAKES Total nearshore area %,20m depth: ( >1km from shore) #2b

J FMA MJ J A SOND

BIOTA kelp beds I IM I■ MN MO MO I■i NM III

plankton bloom I III ■

Prijjailia 17117111711■ ■ I III I• =. 11.1=11 1 .MI1 III= NM NM NM IMI MI ICE COVER Ig I ■ MIN MN ■I III IN I\ i k 1 i 1/10th (mean) MI IIMI I•1Ib ■I1 ■

PRECIPITATION rain 11 111111111 111111111 rie 4/4111111111111111111110/ ZAP # 111111111 snow "fI11111111 11111111 /A 1= I VISIBILITY I " 1 T 11- I I

4 1 k m 723-- 1WITIMITIr — irlairlfral lin

i I 1= til WATER CLARITY ---- !

I I 1 11117171111771-1-1171171.717171171717117: --- 01 I 1 WIND --. = ! HSI < 2 knots ULU 11 pm j :1 0! tal El El = - 1- 1 I r . !! >20knots ill 1 ; 1 1 l 1 L... =1 " = E - - 1 1 - ! i I fini

thunderstorms II

I I I !! U I ! —..... --. Other: BIRDS I 1 I —MOO M■ 4111•1111 I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111 111 1111 11 1111111111 11/4/1/7//4111■11

Extrapolated data I (IIIIIIIIIIillllllllllillllll /////// —

Interpreted data

Not applicable due to ice cover: * * * *

GREAT LAKES Region

Subdivision #3

Primary Limiting Factors: continuous belt of nearshore shoal waters along most of the coast of Manitoulin Island and the mainland.

Secondary Limiting Factors:

ice is present for up to 4 months each year,

on the mainland coast, stream runoff during the spring freshet and winter storms in November to January can result in high sus- pended sediment loads in the nearshore that could affect water clarity; similarly, plankton blooms in May and occasionally throughout the summer could limit water clarity,

in southern sections, erosion of unconsolidated coastal cliffs significantly affects water clarity during the open-water season,

flight operations may be affected by snow and strong winds in winter (November to February), by summer thunderstorms, and by spring and fall bird migrations.

Data Base and information Gaps:

data base adequate in most cases for this study, but deficient in biological parameters.

6.49

Region GREAT LAKES Total nearshore area 20m depth • 2 741 km2 #3 ( > 1km from shore)

JFMA MJ JASOND

BIOTA kelp beds plankton bloom IIIIIIIIIIIIIIIIIIIIIIIIIIIII 111111111111111111111111111 111111111 a■ sm. *m JIIIIIIII ICE COVER pa—. --.....--.

?_ 1/10th (mean) ___ ! ._

PRECIPITATION rain pm 111111111111111111 111111111 11111111 unuisminemni ►zeze. 11111111 1111111111 snow .iltl,ffilifi HIll 111111111/77

VISIBILITY

4 1 km 1111111111 , 1111111111111111111111111111111111111 111111111111111111111111111 111111111

WATER CLARITY W IIIIIIII1MIII111 111111111$111111111111111111 111111111111111111VIZZA

WIND < 2 knots

> 20 k nots 6/411111111111111111 111111111 111111111 111111111 PZ/ZZA thunderstorms 117 111111111 III I i I I MN MIN III I Othe r: I I IMS IIMM BIRDS I 6 ! ■ I I

II IMO NM

I

LEGEND: PARAMETER FREQUENCYIFITITITITIMMIIIIIIIIII WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111111111111111111///7/7 1111

Extrapolated data 1111111111111111111111111112/WM

Interpreted data

Not applicable due to ice cover: * * * * GREAT LAKES Region

Subdivision #4

Primary Limiting Factors: entire lake area is less than 20 m in depth.

Secondary Limiting Factors:

water clarity usually very poor due to erosion of unconsolidated coastal cliffs, resuspension of bottom sediments by waves, and river-borne fine-grained sediments: would essentially preclude laser operations during the open-water season.

Data Base and Information Gaps: data base, including water clarity, adequate for this study. 6.51

GREAT LAKES 661 km 2 Region Total nearshore area c20m depth: #4 ( >1km from shore)

JFMAMJJASONDI

BIOTA kelp beds _ plankton bloom liliiiiiillIEVZ17/11111111110111/ZZ,ZZZA111111111

ICE COVER ilL I IN ...., 7

>_1/1 Oth (mean) I MO IBM MI

PRECIPITATION rain 1111111111111111111110111/71Z/ZZA11111111111111111111111111111111111111 11111111 111111111

snow VA/411111111;11111111 111111111 111111111 ITFC i II II iE 1 i= ii Ii I - II VISIBILITY I 1= --= 1 I 1 11117iii 1 s ! REM :III= IiiirIll

4 1 km

WATER CLARITY ,

WIND < 2 knots I

Ii 111111111111111111)11111111 111111111 II IEE II

>20knots . 71VER:

thunderstorms 111111111 11111110111111111111111111 111111111 111111111 L IA 1 11 II II II II II I Other: I 11 i i I

1

LEGEND: PARAMETER FREQUENCY117171] WITHIN THE MONTH: Par RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data iimmitimuniminivzz####

Interpreted data

Not applicable due to ice cover: * * * * 6.52

GREAT LAKES Region

Subdivision #5a

Primary Limiting Factors:

extensive area of shoal waters adjacent to the coast and in western areas.

Secondary Limiting Factors:

water clarity very poor due to stream runoff, coastal erosion, and resuspension of lake sediments: laser operations would be largely precluded throughout the open-water season.

Data Base and information Gaps:

data base, including water clarity, adequate for this study. 6.53

Region GREAT LAKES Total nearshore area gc 20m depth: 3 , 077 km 2 ( >1km #5a from shore)

J FMA MJ J A SOND

BIOTA kelp beds

plankton bloom ...... LI /dr I:4111111 ZAIZZZZA111111111 ICE COVER — ------a 1/10th (mean) .. __. iiniiii

PRECIPITATION rain P1111111 111111111 1111111110V#,ZkdrA11111111111111111111111111111111111111111111111 1111111111 snow "'Annuli num 111111111111111111 VISIBILITY 4 1 km 11111111111111111111111111111 111111111 11111111 iiimmollimmiliim

WATER CLARITY I

WIND < 2 knots 1111111111111111111111111111 1 > 20 knots "'Annul infimptili min miiiiiirz i nun thunderstorms 11111111 11111111111111111 111111111 111111111111111111 - I 1 i I 11 I 1 I 1 Other: I ____ i 1 ---

BIRDS I

MEI ■II I 1

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 1,71/Z/Z7111=1111=11111

Extrapolated data imitunammilmmlyZZIZZIVINIIIIIIMII11111 ■1111

Interpreted data 111111111111111111111111111rlyZ/M,

Not applicable due to ice cover: * * * *

6.55 km2 Region GREAT LAKES Total nearshore area it 20m depth: 3.883 ( > 1km from shore) 115b

J FMA MJ J A SO ND

BIOTA kelp beds plankton bloom 11111111~17/1. allieetZeZZA1111111111

ICE COVER 1 =IN M ■ I 1 II 1N i iL 0 MID ME I I Inn MM. I I 1. a ■i. 1 /10th (mean) MIMI i

PRECIPITATION ra i n 111111111111111111 111111111"####4 1111111111111111111111111111111111111 111111111 rti 111111111

snow 111111111 11111111111111111 11111111 111111111 IE 1.= 1:-E1 VISIBILITY I= -1 - IIIIIIIIIIIIIIIIII 111111111 IIIIIIIII IIIIIIIII 1 .1111E1711171-11 j

1 km

• WATER CLARITY

WIND < 2 knots 1111111111 111111111 111111111 11111111 1111111111 111111111r#11111111111 =

I III I IIIIIIIIIIIIIIIIII VA1111111111111111111 Ti > 20 knots " I I I I II IL I 1 ! I 1 II II II L ■ ■ ■ ■ I . •••• •••• IIM•• NM. al • • .• 4 I ■ mi. 0 a l I

■

■ MIMI ONO •=1 th understorms IMININ M 41=• • I MEM •

• 1 ! II 1 11= 1=1 II 11 I .-..... __, BIRDS

Other: 7- - JI .1 1 1 1 ! I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data minniiiimmmiurzzzzez

Interpreted data

Not applicable due to ice cover: * * * * GREAT LAKES Region

Subdivision #6a

Primary Limiting Factors:

nearshore waters shoal along most of the coast.

Secondary Limiting Factors:

laser bathymetry would be significantly limited by turbidity due to suspended sediments from cliff erosion and stream run- off throughout the open-water season.

Data Base and information Gaps:

data base adequate for this study. 6.57 725 Region GREAT IAKFS Total nearshore area c 20m depth • km2 ( > lkm from shore) #6a

J FMA MJ JASOND

BIOTA kelp beds plankton bloom IM11111111111111WW "111411111111 111111111 1111114111111111 ICE COVER 1/10th (mean)

PRECIPITATION rain 11111111111111111 111111111 111111111 11111111 111111111111111111011111M 111111111111111111 11111111 111111111. snow 111111111 11111111 111111111 1111111 I VISIBILITY 1 271 = 1 pEililiq IiiiIIIIII i FE iTiEsi (IIIIIIIIIIIIIIIII

4 1 k m RIM,

WATER CLARITY fri. I 1 1 li 1 la Millila 1.11/74(MI 11 I Ir

WIND < 2 knots 111111111111111111

> 20 knots 111111111 111111111 11111111 111111111 1111111111 11111111 111111111 thunderstorms 11111114111111111 111111111 11111111 11111111 II ! I I 1 I I I I II Other: i I 1 BIRDS ■ I I . ! I 11 B NNW I I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data III 11111111min III I I I I I zr z,77/4ils■MII

Extrapolated data 11111111111111111 11 1111 1 11 1 111 /4/7/M

Interpreted data miiminimmtimmincemmANN■

Not applicable due to ice cover: * * * * GREAT LAKES Region

Subdivision #6b

Primary Limiting Factors:

extensive nearshore shoal areas.

Secondary Limiting Factors:

water clarity generally poor and would significantly limit laser operation throughout the open-water season; sediments derived from cliff erosion and river runoff.

Data Base and information Gaps:

data base adequate for this study. 6.59

k m 2 Region GREAT LAKES Total nearshore area c 20m depth • 1,008 ( > 1km from shore) #6b

JFMA MJ JASOND

BIOTA kelp beds

_ plankton bloom Hmuniiiiiiiiimi pm, ,1,111111111111111111i111111111 111111111

ICE COVER -...... -- I= --•

a 1/10th (mean) 1 • 1•1•B OM NM .1•11• • ---

PRECIPITATION rain 1111111111111111111111111111,A,Z#Z,1111111111 111111111 11111111VZ,ZA111111111 snow elie#13111111111 11111111 tey. i I

VISIBILITY 1=

1 4 1 krn I liiiiiiimilimiliii jinthluiliiii Hole

gramr

WATER CLARITY

WIND .1 h. • ■• < 2 knots 1111111111111111111

> 20 knots 111111111l11111111111111111111111111111 111111111 111111111111111111 thunderstorms 11111111 1111111111111111111 111111111 11111111' --- ...... I II I I I I II II I I I

Other: BIRDS U I I I 11 IM MI.= 1 I I I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

*RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 1/7Z/Z,771111111=MMI

Extrapolated data mitimilliminimmilfzzzm

Interpreted data 11111 111111111111 11111 1111111 1/71/rn

Not applicable due to ice cover: * * * *

'9 O3 01INV11V 17 SV I 6.61

6.4 ATLANTIC COAST

6.4.1 Logistics

All coastal areas are within the minimum three-hour transit time from a suitable airfield. Most sections of this region would be within a one to two-hour one-way transit from an airfield with fuel supplies.

6.4.2 Physical Geology

The physiography of the Atlantic Provinces is dominated by three elements:

• the resistant Appalachian system of Nova Scotia and Newfoundland,

• the resistant Shield coast of the northern Gulf of St. Lawrence,

• the unresistant sedimentary rock lowlands of the southern Gulf of St. Lawrence.

The resistant sections of the coast have a nearshore shallow fringe in areas of low backshore relief, for example, the outer coast of Nova Scotia, but, as relief increases, the extent of the nearshore water depths less than 20 m decreases. The northern Gulf of St. Lawrence and outer Nova Scotia have a relatively continuous band of nearshore shallow water, but the most extensive shoal area, is in the southern Gulf of St. Lawrence (subdivision 6: Table 6.5). In this area marine processes have eroded the relatively unresistant sandstone bedrock on the coasts of Prince Edward Island, Northumberland Strait, eastern New Brunswick and the Magdalen Islands. This subdivision accounts for more than one-third of the water depths less than 20 m in the Atlantic Provinces.

Two areas of interest, due to the continuously changing bottom 2 topography, are Sable Island, which has over 850 km under 20 m depth in a single shoal area, and the nearshore area of the Magdalen Islands. 6.62

Table 6.5 Atlantic Coast - Bathymetric Areas (subdivisioon boundaries are given on Fig. 6.6)

Subdivision Area with Depths <20 m (km2 )

1 1,970 2 2,406 3 6,512 4 1,700 5 12,731 6 2,453 7 3,338 8 2,434 9 862

Total 34,496 Figure 6.6 Atlantic Coast subdivisions. Areas with solid shading are suitable for laser bathymetry; cross—hatch areas have water depths <20m, but are considered unsuitable due to poor water clarity. 6.64

A significant factor of the coastal geology is the presence of unconsolidated glacial deposits in the shore zone of many sections. These deposits, for example, the drumlins on parts of the outer Nova Scotia coast, are easily eroded by marine processes and locally supply large volumes of fine-grained sediments to the nearshore waters. This type of unconsolidated deposit is less common on the coasts of the southern Gulf of St. Lawrence, but in this region the easily eroded sandstone bedrock also contains fine-grained sediments that may be transported alongshore or offshore in suspension.

6.4.3 Oceanography

Wave-energy levels on the exposed Atlantic coast are high. The east-facing open coast is influenced by waves that are generated locally in the western North Atlantic. It is a storm-wave environment, with wave periods usually between 4 and 10 seconds, in comparison to the swell-wave environment of the Pacific coast. There is considerable variation in wave energy in both time and space. Although offshore wave energies are much greater in the winter than the summer, the winter winds are primarily from the northwest and hence the coast of Nova Scotia is relatively sheltered. In the more sheltered coastal areas of the Gulf of St. Lawrence and the Bay of Fundy, the significant wave heights are generally less than 2 m, with maxima occurring in the winter months. The wave energies vary geographically with shoreline orientation and fetch distances.

The importance of ice in the coastal zone increases from south to north. The southwest coast of Nova Scotia is virtually ice-free; whereas, ice is present in the nearshore zone for up to 4 months each year in the Gulf of St. Lawrence.

There is considerable variation in the tidal range throughout this region. The outer coasts of Newfoundland and Nova Scotia have mean ranges of 1 to 2 m. In the Gulf of St. Lawrence, the mean range is quite variable but less than 2 m, and in the St. Lawrence estuary, the mean range increases from 2.3 m at Sept Illes to 4.1 m at Quebec City. The Bay of Fundy has exceptionally large tidal ranges that increase from 5 m at the 6.65

mouth to 12 m in the head of the Bay. The tides are mixed or semi-diurnal, except for one small area in Northumberland Strait and another near the Magdalen Islands where the tides are mixed, mainly diurnal.

The water clarity of the Atlantic coast is, in general, much lower than that of the Pacific. Areas such as the Bay of Fundy and southern Gulf of St. Lawrence have highly turbid waters year round. The remaining southern coastal waters have high organic concentrations during the summer months which reduces the clarity. The waters of the exposed Newfoundland coast have the highest clarity year round, and the Atlantic coast of Nova Scotia is clearest during the winter months. Coastal waters can be highly turbid due to suspended material introduced by river inflows, especially during spring freshets, but most of the Atlantic coast rivers are small and hence their impact is very localized. The St. Lawrence River is a major 3 -1 source of freshwater (average annual discharge of 14,000 m s ) and suspended material.

Anchored vegetation is not as prevalent as on the Pacific coast and is restricted to the more protected embayments with insignificant freshwater sources and to the intertidal areas of the rocky coasts.

6.4.4 Meteorology

The climate of the Atlantic coast is considerably colder than that of the Pacific due to the location of the area on the eastern side of the North American continent. Winter temperatures are considerably lower by comparison due to the movement of cold air eastwards from the interior of the continent.

The meteorology of the region is also affected by the warm Gulf ' Stream current that flows north along the east coast of the United States and by the cold Labrador current that moves south along the western margin 6.66

of the Labrador Sea. The combination of these three primary influences results in the presence of sea ice in winter, in sheltered waters, and fog on open-ocean coasts, in summer months.

The primary weather systems of the region are cyclonic storms that _ cross the area from southwest to northeast. These depressions are most frequent and intense in winter months, when up to 10 per month may occur.

In terms of limiting parameters, the presence of sea ice, between December and April, and summer fog are the most significant factors. Strong winds or turbulence are associated with cyclonic storms, and may be locally limiting in winter months.

6.4.5 Regional Analysis and Summary of Limiting Factors

Summary tables of the limiting factors are presented for each of the subdivisions in this region. The bathymetric areas are summarized in Table 6.5, and the distribution is shown in Figure 6.6, and at a scale of 1:3,500,000 on the map that accompanies this report.

The shallow-water sections of this region are associated with coasts of low relief, along the north and south shores of the Gulf of St Lawrence and the Atlantic coast of Nova Scotia. Although these shallow areas are not extensive offshore, except in Northumberland Strait and adjacent to the Magdalen Islands, they are relatively continuous alongshore.

The major factors that limit the use of the laser technique in this region are ice and water clarity. Ice is present in the Gulf between three and five months each year, but is less limiting on the outer Nova Scotia coast. Water clarity is significantly limiting in the southern Gulf due to sediments that are derived from river runoff, coastal erosion, or resuspension. This is an area of unresistant bedrock outcrops and unconsolidated glacial sediments. The latter are present locally throughout the region and, therefore, may be a limiting factor where they are eroded by streams in the catchment area of by waves at the shoreline. 6.67

Thus, although the southern Gulf has the largest potential in terms of an extensive continuous area with suitable water depths, this is offset by limitations associated with the turbid waters that characterize this area.

Those sections of coast where water depths are suitable and where water clarity would likely be adequate are primarily rocky areas. The growth of anchored vegetation on the rocky substrate may be a limiting factor on the accuracy of depth measurements in these areas.

In terms of flight operations, fog is a significant factor in summer months due to the interaction between cold and warm air masses over the Gulf Stream and Labrador Current.

There exist few areas in the Atlantic region where the technique could be applicable over a large area, due to environmental rather than depth limitations. The primary results from the analysis for this region are as follows:

• Resistant rocky coasts with low backshore relief usually have adjacent shallow waters. The only limiting factors would probably be anchored vegetation (on measurement accuracy), and ice, storms, or fog (on flying operations).

• Areas of low relief and extensive shallow waters, but with unresistant bedrock outcrops or unconsolidated sediments, are usually characterized by high concentrations of suspended sediments during the open-water season; thus, operations could be precluded due to poor water clarity.

• On the sandy shoals of Sable Island and the Magdalen Islands, strong wave action can resuspend sediments and reduce water clarity, in addition to other factors that may be in these areas.

• Few extensive areas exist in the region where the technique could be used, although it may be feasible along continuous, but narrow, bands of coastal waters. 2 • An estimated 34,500 km in this region has water depthsless than 20 m; of this total, only an estimated 17,500 km (51%) is suitable for, laser bathymetry due to limitations associated with water clarity during the open-water season. Region ATLANTIC COAST

Subdivision #1

Primary Limiting Factors:

shoal areas are scattered and discontinuous, only extensive area is between Fogo Island and Bonavista Bay.

Secondary Limiting Factors:

ice would limit operations for up to 5 months each year (January to May),

fog is generally an operational factor from April to July and winter storms or snow may be limiting from October to March,

plankton blooms may limit water clarity locally in June and September,

water clarity generally good as rivers have low sediment yield and coasts are bedrock,

rooted marine vegetation may be significant locally on rocky coasts,

bird migrations may be a factor in May and June.

Data Base and information Gaps: oceanographic and meteorologic data base adequate for this evaluation except for water clarity data. 6.69 Region ATLANTIC Total nearshore area e 20m depth • 1,97o k m 2 ( >1km # 1 from shore)

JFMA MJ JASOND 1E 1E- iEl I 1E N - IFIN iii BIOTA = - "I 1 1 1 I

kelp beds 4 , 1 plankton bloom1 i i 1 1 1

ICE COVER a 1/10th (mean) itAIIIII III

PRECIPITATION rain 1IIA1Ill11111111111111111[111111110WMMIMZMAffil1iff snow Virzzi,,ammunnii ii 1 FIT1111711111r 1E 1;

VISIBILITY 1111001 1= 1= 1E LEI I 1- 1= 1E' 1= E j = 7: 771 -! 1 1 97 - 1 1 1 1 1

41km ......

WATER CLARITY . 171% 111—.1.77ZZOI — -11711.17

WIND < 2 knots

> 20 knots 111W272211MAKIIRILIMIRIJ n ITOMr111111111117) thunderstorms ------I

Other: . ,-- BIRDS . --.... 1

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 111111111111111111111111111111 efe/M ■ Interpreted data illm11111111111Hinticezzzizedrim

Not applicable due to ice cover: * * * * 6.70

ATLANTIC COAST Region #2 Subdivision

Primary Limiting Factors:

shallow waters are common as a thin coastal belt but are discontinuous:

Secondary Limiting Factors:

ice could limit operations between one and three months each year,

significant flight limitations could include fog (April to August), winter storms and snow (October to March), and bird migrations (May-June: October-November),

plankton blooms generally occur in June and September and could be locally significant; otherwise water clarity good as rivers have low sediment yield and coasts are rocky,

on shallow rocky areas, rooted vegetation may limit depth accuracy.

Data Base and information Gaps:

data base adequate for this evaluation except that water clarity data is limited. 6.71 Region ATLANTIC Total nearshore area %20m depth: 2,406 km 2 ( > #2 fkm from shore)

J FMA MJ J A SO ND FR ff IS! T !-= 1 ISI l l= i 11 IE. 1E = ■ 1 -7 gi =

BIOTA 1 - - -! .1 :1 1 11 1 P 1 liniq

kelp beds " I ! :I I I

I % _ - - .1 !

plankton bloom I

----

ICE COVER 1/10th (mean) 1111111H IS I N LS Ii i PRECIPITATION ll I I I ! . rain EteTke.i 7.A i I iE 1= i ∎ _I

- 1 snow ! 1 j I 1111117 !

I

iNi la I glair !N ! 1 1\ VISIBILITY IC a ∎ ■ - I _ I 1 1 II1111111 111111111 111111M 1 4 1 km Rid

WATER CLARITY k; 117 1 ri ifer22, :01 r:12

WIND ------< 2 knots

> 20 knots 11111,77:1ZMPM(11111fil TIMM 111.11111111U.11111■(.44MINIM thunderstorms - - --- I .

Other: ---1

.,_ - 1 ,--- 1 I I

BIRDS _

— 1

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1 111111 11 111111 11 111111 11 1111 V7,7',/,41111■1111.111.

Extrapolated data 111111111111111111111111111111 Zet/ZZAIIIII■

Interpreted data

Not applicable due to ice cover: * * * *

ATLANTIC COAST Region

Subdivision #3

Primary Limiting Factors:

northern Gulf has a relatively continuous belt of waters less than 20 m; on the west Newfoundland coast, these are limited and discontinuous.

Secondary Limiting Factors:

ice would prevent surveys for up to 5 months each year (January to May),

flight-limiting factors would include fog (June-July), winter storms (November to March), and bird migrations (May-June: October-November),

water clarity may be limited by plankton blooms in June and September and by sediment runoff, adjacent to rivers on the north shore, during the spring freshet (April to June),

rooted vegetation may be limiting locally June to September.

Data Base and information Gaps:

information generally adequate, but little data on water clarity.

6.73 6,512 km 2 Region ATLANTIC Total nearshore area ‘c20m depth: ( >1km from shore) #3

J FMA MJ JASOND Taffigil -- ig! !S I IA FM RI , BIOTA i 1 , 11

kelp,_. beds n ki IN I !

...... I _ plankton bloom

ICE COVER a 1/10th (mean) 11111111 r: IS I\ IN IS R Iv ! !S 2 PRECIPITATION Y 7 _ 41

1 • 1 I I

rain I 1 i g • I !

snow ! I !

- xi 1= t= 11- I I I . I ■ = VISIBILITY = I • I•1••• ±1 , - 1 1 ! I I IIIIIIIIU

111111111111111111111111ifir MI IBM NMI

4 1 km -1

!S !! IV #.4 WATER CLARITY . . . !N • I ! I I I I •

WIND .....— — - <2 knots

> 20 knots mrzeirrAiniiiii Inimunimiti ovum 11111119/# . thunderstorms

Other: ----i BIRDS -- ---t -- H---

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111 1 1111111 1 11111111 1 11111 rzeizz,"*.mmi

Extrapolated data IIIIIIIIIIIIIIIIIIIIIIIIIIIIII //I'M

Interpreted data 1111111111 1 1111111111111111111f/1/7/ 11

Not applicable due to ice cover: * * * * ATLANTIC COAST Region #4 Subdivision

Primary- Limiting Factors: extensive shallow areas on both shores of the estuary.

Secondary Limiting Factors:

ice is present for up to 4 months each winter,

plankton blooms are not significant as this is an estuarine environment, but water clarity would be significantly af- fected by suspended sediments during spring and fall freshets,

flight operations may be limited by winter storms (November to March).

Data Base and information Gaps:

data base generally adequate for this study, although little information on plankton. 6.75 Region ATLANTIC Total nearshore area .c 20m depth: 1,700 km 2 #4 ( >ikm from shore)

J FMA MJ J A SOND liN 11

- r •■•- BIOTA , kelp beds 1 „' V tt plankton bloom e 111111111 ..""r1111172.2. ICE COVER .>. 1 /10th (mean) 1111111111

PRECIPITATION rain InifitrezzeizezelzdWZIonitt snow UW14111111111 111111111 11111111 0",

VISIBILITY <1km 1111111111 111111111 111111111 111111111 111111110111111111111111111 111111111

WATER CLARITY Iiiiiiiinezzzi.tinimezzzlimillinittive., .

WIND < 2 knots 1111111111111111111 111111111 111111111 111111111 111111111 '''''''''' EiriTAAINIMez > 2 0 knots 11111q:7%?;711.1.1111arlE111 rill IIIIN ._._. thunderstorms 111111111 111111111 111111111 --...—

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 11 1 1111111111 1 1111111111 1 11111 IZZ.ZeZZ

Interpreted data 111111111111111111111111111111,////// . 1

Not applicable due to ice cover: * * * *

ATLANTIC COAST Region

Subdivision #5

Primary Limiting Factors:

extensive areas with water depths <20 m adjacent to the coasts of Baie de Chaleur, east New Brunswick, Prince Edward Island, northeast Nova Scotia, and Magadalen Islands.

Secondary Limiting Factors:

ice is present from December to April and would limit operations,

in all of the shallow areas, water clarity probably would be significantly affected by high suspended sediment con- centrations all year due to (1) coastal erosion of unresis- tant sandstone bedrock or unconsolidated sediments (October to March), (2) high river runoff (April to June), (3) re- suspension of fine-grained materials by wave action (October to March), and (4) plankton blooms (May-June: September).

Data Base and Information Gaps: data base generally adequate for this study but little information on plankton. 6.77

Region ATLANTIC Total nearshore area 20m depth: 12,731 km 2 ( > lkm from shore) #5

J FMA MJ JASOND [II ..--• BIOTA w\I 1\ I .1 I != 1 EI E77 \1 I' 71 = - - i 1 ...... 1 kelp beds - T; Ni N

d ----.

plankton bloom .--- II - - ICE COVER 2 1/10th (mean) 1111111111

PRECIPITATION

rain FO IIII iii 1 1 II

snow 1 1 . F27.;

V): VISIBILITY

4 1 km 1111111101111 11111M111111111 11111111 111111111011111 117113.7111Traill711I

II il II WATER CLARITY IMMI II■ IMMI ffil■ M, III I■1 EMIR ■11111 I l 1

MI IMM IN= l■ IN=1 I■ ■ NMI 11=11 MII

W IND < 2 knots (1111111111111111llllllll111111111111111 11111 H1111111 11111111 11111111 11111111 111111111 11111111 111111111 > 20 knots INIIIV/i1:4111111111 11111111 1111111111 111111111 11111111 r4r, thunderstorms 717111171T11111 ..-1 !I 1 I ! Other: i ; I

BIRDS I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

'RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 riwzmi■mi

Extrapolated data IIIIIIIIillllllllllllllllilll zzzezirmim■

Interpreted data

Not applicable due to ice cover: * * * *

ATLANTIC COAST Region

Subdivision #6

Primary Limiting Factors:

shallow water common along most of the coast.

Secondary Limiting Factors:

ice is present each year for up to four months,

adjacent to rocky coasts, water clarity would be affected by plankton blooms (May-June: September), anchored vegeta- tion may be a limiting factor; but where glacial deposits occur at the shore or in catchment areas, suspended sedi- ments may be significantly limiting during periods of wave action (October to March) and the spring freshet (March to June),

flight operations may be limited locally by fog (May to July), bird migrations (May-June: October-November), or by winter storms (October to March).

Data Base and information Gaps:

physical oceanography and meteorology data base adequate, but little information available on water clarity. 6.79 ATLANTIC Region Total nearshore area c20m depth: 2 , 453 km 2 #6 (> 1 km from shore)

J FMA MJ J A SOND [ p1 TP TA =p- - L--1 I 1 1 71 = !. - =- 7

BIOTA . ni , A kelp beds - tIZZZi W.1;,

7- 11

plankton bloom ,

IV2' Pi ICE COVER at 1/10th (mean) 111111111

PRECIPITATION rain IllInffillffiniffilliciiiimiezzmzzzAezrzzzr■ 1

snow VAIZIZA111111111 11111111 L "g 1171 II 1.7 VISIBILITY 1E1 s; -1 .

4 ik m PrInil FITINTIFIIT,171277.;. 1 ,ifigg

WATER CLARITY IS

077,7%-el *; Ili ! (Kiel:

WIND < 2 knots

> 20 knots W.../%41111111.111,111U111i111JUIlli.....1111111111111111WZ. --- """"" thunderstorms I Other: •----• ....—• I I

BIRDS --.--- . I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111 1 111111111 1 1111111111111

Extrapolated data 11 1111111 11111111 1111111 1111WV/M PIM MO IN= WNW ORM

Interpreted data limummummunifetze.e.r

Not applicable due to ice cover: * * * *

ATLANTIC COAST Region #7 Subdivision

Primary- Limiting Factors: shallow water common along most of the coast.

Secondary Limiting Factors:

ice is present in sheltered inlets and bays during periods of cold temperatures,

adjacent to rocky coasts, water clarity would be affected by plankton blooms (May-June: September), anchored vegeta- tion may be a limiting factor; but where glacial deposits occur at the shore or in catchment areas, suspended sedi- ments may be significantly limiting during periods of wave action (October to March) and the spring freshet (March to June),

flight operations may be limited locally by fog (June to August), bird migrations (May-June: September-October), or by winter storms (October to March).

Data Base and information Gaps:

physical oceanography and meteorology data base adequate, but little information available on water clarity. 6.81 3,338 km 2 Region ATLANTIC Total nearshore area c20m depth: #7 ( > lkm from shore)

JFMAMJJASOND --- _ mmarala BIOTA 'Z(0272721. " kelp beds r

iuntaliumuumen 1S SR KI ki ■

_ plankton bloom :::::: — 1 1:

OTIT 1 ICE COVER a 1/10th (mean) 1111111110.11

PRECIPITATION 7.1"/./ rain 1110111111111111 11111111fredrf#,Z1,12111111111)1111111VIWZM snow 9/AreAumm 111111111 11111111111111111 7 !Si VISIBILITY El 0111

4 1km mimiq OIMITIMEEM PIM MIME=

Ij IN V1171.471,4111111 WATER CLARITY K I .

■ 1 . WIND < 2 knots

> 20 knots ifzik")Tiiiifiiiiiiii15135TriTir - 7101111fIgilkaNIM thunderstorms 111111111111111111k . I II I I Other:

BIRDS 1 I -1- -I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11 11 11111 11 11111 11 11111 11 1111

Extrapolated data 11111 1 1111111 1 1111111 1 1111111 1 rzezzmm ■

Interpreted data

Not applicable due to ice cover: * * * * ATLANTIC COAST Region

Subdivision #8

Primary Limiting Factors:

limited but locally extensive shoal areas at head of the Bay.

Secondary Limiting Factors:

high suspended sediment concentrations would preclude use of the laser techniques at all times of the year.

Data Base and information Gaps: data base adequate for this evaluation. 6.83 ATLANTIC 2,434 Region Total nearshore area 20m depth: km 2 #8 ( > 1 km from shore)

J FMA MJ J A SOND I_ I ! BIOTA --- . M IMIIIII IMO . i ' 1

.. ■ ■ kelp beds ___ — M I plankton bloom )111111111111111111F IZMWei

ICE COVER a 1/10th (mean) MI11111 111111111 IIII 1 . 1 PRECIPITATION §111 rain WO 110127721.2227,4101 146 snow urizz miffigr-_-: 1

IIIM 1=1 1= iI IE I

VISIBILITY !NI . I 1 4 1:5Miligii 557011! liMr 'llininininit imilai

1 km

WATER CLARITY PFiI 71 11 I' I I I II II I I ! 1 11111=1111.1111111 WIND -• • -- --• • --

- 1

< 2 knots I I II I --. INNMMN IMO=NM - • EMI NMI I 1 1 I

=

-- 1

>20knots //% (III iiiiiiiiiiiiii677[If - El II II

■ I ■ Milli thunderstorms I M. IMUNIMI INIIM 1■11111 NI 1“11MI I= =.• IIIMOI =MI

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111 11111111111111 197,///17111MINNIMINI

Extrapolated data 11111 1 111111111111111111111111/,

Interpreted data imin nimunim mitilfmm

Not applicable due to ice cover: * * * * Region ATLANTIC COAST

Subdivision #9

Primary Limiting Factors:

the large shoal that forms the Sable Island Bank.

Secondary Limiting Factors:

water clarity may be limited by plankton blooms (May-June: September) and by resuspension of sediments by wave action (November to March),

flying operations would be affected by winter storms (Novem- ber to March) and by fog (April to August).

Data Base and information Gaps: data base adequate for this evaluation. 6.85 862 km 2 Region ATLANTIC Total nearshore area ic 20m depth: ( > 1km from shore) #9

J FMA MJ J A SOND I BIOTA kelp beds plankton bloom 7: p uzw7272-Ai r m ow. imars-_—_- ICE COVER a 1 /10th (mean)

PRECIPITATION ra i n VIA 11111111WIZ" /1". A WI, IL11ZZZZOZ e. / snow M111111111111111 111111111 11111E1111

VISIBILITY 111111111 ummommitY4/7,:zjwawe1 ■ miiiiiniminimini 111111111 4 1 k m IS WATER CLARITY o ! a I .•■ =IM NM OEM

WIND < 2 knots

> 20 knots 1111111VM lIllIllIl 11111111 111111111 111111111111171WAIM thunderstorms

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1111111 1 11111 11 111111 111 1111 11/77/Z/Z411011•1

Extrapolated data ininimmilifinnyzzem

I i mm i nitim il mirezitz," Interpreted data rt Not applicable due to ice cover: * * * *

'9 S MH OSC N 9 AV 6.87

6.5 HUDSON BAY/LABRADOR COAST

6.5.1 Logistics

All parts of the nearshore area within this region are within the minimum three-hour transit time from a suitable airfield. This is a large region with a small, scattered population so that many areas fall within a two to three-hour one-way transit range. A number of secondary air strips without fuel supplies exist in the region, and it is possible that these could be used as temporary staging sites for a survey.

Although all areas are within the minimum stipulated transit time, this assumes adequate flight conditions and that an alternate landing area would not be required.

6.5.2 Physical Geology

This extensive sub-arctic region is comprised of two distinctly separate geologic units. The Labrador coast is a region of old, resistant rocks that have been folded and faulted by mountain-building processes and subsequently eroded by glaciers and ice sheets during the Pleistocene. The area is one of steep backshore relief in most sections, with a fjord coast and deep nearshore waters. The only extensive lowland area is in the Cartwright and Lake Melville sections and, apart from scattered shoals, this is the only section of the coast with water depths less than 20 m. The coasts of Hudson Strait (Unit 5: Table 6.6) are similar in most respects to the upland coasts of Labrador, although relief is in the order of 500 m to 1000 m.

Hudson Bay is a large shallow depression in the centre of the Canadian Shield. The basin has been flooded through channels in the north to become a large "inland" sea. Ungava Bay is a secondary depression in the Shield adjacent to Hudson Bay. It is bounded to the east by the mountains of the Labrador coast'and to the west by the upland area of the Larch Plateau and forms the east rim of the Hudson Bay depression. 6.88

Table 6.6 Hudson Bay - Bathymetric Areas (subdivision boundaries are given on Fig. 6.7)

Area with Depths Subdivision <20m (km2 )

1 > 1,050 2 >19,750 3 >700 4 19,010 5 >900 6 6,150 7 3,728

Total >51,288

(Note: actual total may 2be as much as 60,000 to 65,000 km ) Figure 6.7 Hudson Bay/Labrador Coast subdivisions. Areas with solid shading are suitable for laser bathymetry; cross-hatch areas have water depths <20m, but are unsuitable due to poor water clarity. 6.90

The southwest coasts of both Hudson Bay (Subdivision 2) (Table 6.6) and Ungava Bay (Subdivision 6) have low relief, less than 30 m, with very wide shallow nearshore waters, up to 30 km wide. In the south of Ungava Bay, there are extensive mudflats, whereas in southern Hudson Bay (James Bay), the muskeg coast is characterized by a wide shallow nearshore environment that has either a bedrock or sand-mud character. Eastern James Bay has numerous large deltas in an area of low relief; whereas eastern Hudson Bay (Subdivision 3) and eastern Ungava Bay have higher relief, resistant bedrock outcrops, and deeper nearshore waters.

The information base on the bathymetry of many parts of Hudson Bay is sparse, particularly in the more northern section. As backshore relief in much of the area is low, for example Chesterfield Inlet, Southampton Island, and Coats Island, nearshore shallow waters would be expected throughout much of subdivisions 1 and 2. An estimated additional 10,000 to 2 15,000 km of waters with depths less than 20 m probably occurs in the northern and northwestern parts of the Hudson Bay region.

6.5.3 Oceanography

Wave-energy levels on the exposed Atlantic coast of Labrador are high. The east-facing open coast is influenced by waves that are generated locally in the western North Atlantic. It is a storm-wave environment, with wave periods usually between 4 and 10 seconds, in comparison to the swell-wave environment of the Pacific coast. There is considerable variation in wave energy in both time and space with wave energies greater in the winter than the summer.

The wave energy in Hudson Bay is limited by the restricted ice-free period. The wave heights in Hudson Bay are less than 2 m for approximately

80 to 90 percent of the ice-free period and greater than 4 m for 1 to 2 percent of the open-water season. The waves are generated locally by the prevailing winds out of the northwestern quadrant with relatively constant 71 velocities averaging 24 km hr annually. During the summer ice-free 6.91

months, the wind direction is more variable and speeds are slightly less. It is to be expected that waves reaching the southern and eastern coasts are of greater height than those reaching the western and northern coasts.

Ice plays a very important role in this region due to the length of the ice-covered season, which extends from November to mid-June or later. Open-water in Hudson Bay occurs only from mid-August until mid-October. Freeze-up is a lengthy process that begins in late October in the coastal inlets of the northwestern sector of Hudson Bay. As the weather grows progressively colder, the ice spreads southward along the shores. By late November, the process reaches southern James Bay. The ice clears first from the shore-zone of James Bay and northwest Hudson Bay in early June and progressively retreats until the entire coastline is ice-free by the end of July. Ice is present up to 7 months each year in the central sections of the Labrador coast decreasing, to 4-5 months in southern Labrador.

The tides in Hudson Strait are extremely large with a mean range of up to 12 m on the north shore and 10 m on the south shore and in Ungava Bay. The tide decreases to a 3 m range to the west approaching Hudson Bay. The 3 m range continues into Hudson Bay and down the west coast to James Bay. On the east shore, however, the range decreases from 3 m in the south to less than 0.5 m in the northern part. The mean tidal range decreases along the Labrador coast from 8 m in the north to 3 m in the south. The tide is semi-diurnal in all areas.

Very little data documenting water clarity in the region has been published, but the wave climate, tidal range, river inflows, and geology of the region can be used to deduce relative values. In Hudson Bay, the east and northwest coasts are within the resistant Canadian Shield, and the nearshore coastal waters are expected to be relatively clear. The southwest and south coasts are bordered by lowlands, and many small and large rivers in this region will contribute significant quantities of suspended sediments. Moreover, the resuspension of fine-grained sediments by wave and tidal action is expected to contribute further to water 6 .92

turbidity in these areas. Similarly in Ungava Bay, the large tidal range is expected to resuspend bottom sediments, so that the water is relatively turbid. The Labrador coast is again composed of resistant rocks, and the water clarity should be relatively good.

Kelp beds and seagrass may exist in this region, but would be limited to summer growth because of the presence of ice cover for most of the year.

6.5.4 Meteorology

The region has a mid-continental sub-arctic climate that dominates the meteorological character. The cold and long winter results in a sea-ice cover that may persist up to 10 months in a year in more northerly sections.

Most cyclonic storms pass over this region in fall and winter, with a maximum intensity and frequency in November and December. Meteorological parameters are otherwise not significant to this evaluation.

6.5.5 Regional Analysis and Summary of Limiting Factors

The temporal variations for each of the parameters are presented for each of the 7 subdivisions in the following tables. The spatial distribution of known shallow-water areas is summarized in Table 6.6, and the geographic distribution is shown on Figure 6.7 and also at a scale of 1:2,202,000 on the map that accompanies this report.

A regional feature that is characteristic of other Canadian coastal areas is the association between low regional relief and shallow nearshore waters. Southern and northern Hudson Bay and Ungava Bay are lowlands and have extensive shallow-water areas. In these subdivisions alone, more than 2 45,000 km of depths less than 20 m are known to occur, compared to a combined total for the Pacific Coast, Great Lakes and Atlantic Coast in the 6.93

2 order of 52,000 km . The figure for the Hudson Bay area does not include 2 as much as 15,000 km that appears to be below 20 m but has not been adequately charted.

The extensive shoals in the lowland areas are also characterized by high concentrations of suspended sediments due to river runoff or to resuspension by waves and tides. Thus, although the potential exists for use of the technique, the environmental parameters associated with water clarity would probably preclude application of the survey method, except in the more northern sections of this region. The data base for water clarity is non-existent or poor, but sufficient information is available to make this preliminary regional evaluation valid. For this region, it would be realistic to assume that, until more data is available to indicate otherwise, use of the technique would not be feasible in the southwest Hudson Bay, James Bay, and Ungava Bay areas.

The evaluation suggests that in nothern sections of Hudson Bay extensive shoal areas may exist in waters that have not been fully charted to date. This area is markedly different from southern sections of the region as the tidal range is lower, fewer and smaller rivers enter the coastal zone, and wave-energy levels are lower due to the prevailing northwest winds. Therefore, although the waters are shallow and the bottom may be characterized by a sediment veneer, it is believed that suspended sediment concentrations would not be high in these northern areas and that the laser technique is potentially viable for bathymetric surveys.

Any consideration of a field programme in the area of northern Hudson Bay should involve a brief reconnaissance survey to assess water clarity. Appropriate reconnaissance survey methods are outlined in Section 4.6. The potential window for a field survey is short, in the order of only three to four months, and the only limiting factors that are apparent from this evaluation might be plankton blooms and occasional periods of strong winds or precipitation. 6.94

In summary, the results of this evaluation indicate the following points:

• Extensive, continuous, known areas with depths less than 20 m occur throughout southwest Hudson Bay, James Bay and southwest Ungava Bay: but these are probably areas with high suspended sediment concentrations that would preclude use of the laser bathymetry technique.

• Eastern Hudson Bay, Hudson Strait, and the Labrador coast have high relief in most sections with only scattered or discon- tinuous areas of shallow water.

• Northern and northwestern Hudson Bay is a lowland region with extensive uncharted waters; the analysis suggests that suspended sediment concentrations would not be high in this region and that the laser technique may be useful for baplymetric surveys. It is estimated that in the order of 10,000 km of water with depths less than 20 m may be present in this region.

• Ice is a significant limiting factor up to 10 months each year; but during the short open-water season, there are expected to be few factors that would limit flight operations in northern sections. 2 • In this region, approximately 60,000 km has or is estimated to have wa.te5 depths less than 20 m; of this estimated total, only 15,000 km would be expected to be suitable for laser bathymetry due to water clarity limitations during the open-water season. HUDSON BAY/LABRADOR COAST Region #1 Subdivision

Primary Limiting Factors: water depths would be expected to be shallow in many (uncharted) areas due to low general onshore and offshore relief.

Secondary Limiting Factors:

ice would limit field surveys between 4 (minimum) and 10 (maximum) months each year,

little known about water clarity other than timing of plankton blooms, but it is expected that river input, coastal erosion and resuspension would not contribute large amounts of inorganic or humic suspended materials,

few factors would be flight limiting except snow (October to December) and bird migrations (May to July: October-November).

Data Base and information Gaps:

bathymetric data base inadequate for this evaluation - possibly up to 10,000 km2 of uncharted depths <20 m,

meteorologic/oceanographic data base adequate (except for wind speed) but no information on water clarity other than on plankton.

6.96 HUDSON BAY / 1,050 Region Total nearshore area c 20m depth • km 2 LABRADOR #1 ( > lkm from shore)

JFMA MJ JASOND

BIOTA .------.--- kelp beds * * * * , - - plankton bloom 11111=111■VA111111111 ICE COVER a 1/10th (mean) .ZZ ,_e/AM ' 1 " I 1g Ei PRECIPITATION 1 111 rainain 1' M I 1 I 1 I * * * * = =1 s - - -

snow 1 a i

Wig riMiK

• lI I= 1E 1 VISIBILITY 1 1

4 1 km * * 1 MS HMI riiiiiiij 1 "_____ *

WATER CLARITY * * * rilliITMITIMmmsrArdMfrrf* —:::: #47,401111111111111111111 1 i 1 I 1 1 I II II 1I II ■ ■■■ MIIIIIIMINI• I , m.. W IND 1 I 1 I I

< 2 knots OM Il■ MI 1 MVO MB I I I

* >20knots 11111111111111111117774/# * * * ......

thunderstorms --• ..—. 1 1 1 1 Other: —.— 1 1 I =101 11, BIRDS 1 ■ NM illM NM NM •

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111111I1111111111V7Z/Z7,71■1■11

Extrapolated data 111111111111111111111111111211/7/M

Interpreted data iminiumminintricemmAN■w

Not applicable due to ice cover: * * * * 6.97

HUDSON BAY/LABRADOR COAST Region 462 Subdivision

Primary Limiting Factors: extensive shoal areas characterize the southwest coast: very shallow up to 30 km from shore, potentially suitable subdivision for airborne surveys,

west coast possibly also shoal but no bathymetric data available.

Secondary Limiting Factors: ice cover, present between 4 and 10 months each year, would preclude use of the technique,

water clarity is expected to be poor because of plankton (July- August) and spring runoff (June-July): and may be limiting during the remainder of the open-water season due to resuspension of fine- grained sediments by tidal and wave action - however no data are available to confirm this,

few factors would be flight limiting except snow (October-December) and bird migrations (April-July: September-October).

Data Base and information Gaps:

bathymetric data for west coast is insufficient to evaluate depth parameters,

data base overall is poor but generally sufficient for this study, except for information on water clarity which is probably a critical parameter in this area. 6.98 HUDSON BAY/ 19,750 Region Total nearshore area ic20m depth• km 2 LABRADOR it 2 ( >1km from shore)

JFMA MJ JASOND II ■ ii BIOTA II OMNI MEI IMM MM I= MEN SEIM MID =I

kelp beds IM ..0 ■I MM1 IINMI I IS MEM MIll MIN IMINI I

* * * * * 7721111.1111P2= plankton bloom

ICE COVER a 1/10th (mean) "%I la I I 1 IS N !S II IL! ■ PRECIPITATION = ! l ! - ! I i ! 1

rain t is! I 1 0 N1

* * * * * 9 oi Z -- I

snow ; I

1

VISIBILITY I ig p

4 1 km * * * * * 1111111111 iliffERMII ! --_ --

WATER CLARITY * * * ,* * lift•IIIIIIMIreget12= r I I II Ii II ■ ■ ■ ■ MI I III 11M= MI 111=11 WIND I -- I 1

< 2 knots INION WM M I ■IO NMI MN NM .1 111=11 OM 1 12 IF-

-

# 1 * # MT 11111111 11111111 11111111 L-- >20knots * * I Ii II ------. ,..-- -

th understorms 10IIIMNM INIM MOIN 0 =IN OM Other: BIRDS * * * * .if 111111ifif

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data 111111111111111111 1 11111111111/ZZ/ZZZAMMOINIMI

Extrapolated data

Interpreted data 111111111111111111111111111t11///////■■

Not applicable due to ice cover: * * * * Region HUDSON BAY/LABRADOR COAST

Subdivision #3

Primary Limiting Factors:

although bathymetric data is incomplete there are no extensive shallow areas in this subdivision.

Secondary Limiting Factors: ice would limit surveys from a minimum of 4 to a maximum of 10 months each year,

much of the coastal shallow areas are rocky and the presence of rooted vegetation may be a limiting factor, especially in late summer,

water clarity would be reduced by plankton (July-August), and perhaps during the spring freshet (May-June): despite the lack of data, water clarity is unlikely to be a limiting factor due to suspended sediments as this is a rocky coast with only scattered surface sediments,

flight limiting factors include snow (October-December) and fog (July).

Data Base and information Gaps:

data on bathymetry, water clarity and meteorology (particularly wind velocities) are poor,

overall data base is marginal for this type of evaluation. 6.100 HUDSON BAY / 700 Region Total nearshore area ,c20m depth: km 2 LABRADOR #3 ( >1km from shore)

J FMA MJ J ASOND On SI KV BIOTA IN!

kelp beds MA? 771—Z1 ] A1111111111111111t: j I MI 1 - =! - plankton bloom .....—

ICE COVER a 1/10th (mean) .111.111.1101111/11MNIV IN jm 1.1 I 1 , LU m=

PRECIPITATION - = - 1 : I rain * 1

if * N 11 If -

snow A I i I

...—

— 2 Up UI II II VISIBILITY II 1.11 I II

* if ... * * i igiffii]

4

1 k m

WATER CLARITY * if * * 1111111 A1111011111111111 -- I

1 . II i I iI WIND -- ...—..— I !MI

< 2 knots I I

*1111111M1111711111111111111111111

II rd 1: 1 1 -- -

I 1 .1i >20knots * * * II 1 i 11.1.1111 I I

I thunderstorms 1

--- Other: BIRDS * * * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111 1 111111 1 1111111111 rmz eivmsmaml

Extrapolated data ntimmitinnim1111 m,77,•■■

Interpreted data 111 11 111111 11 111111 11 111111V##4 'I'##

Not applicable due to ice cover: * * * * 6.101

Region HUDSON BAY/LABRADOR COAST

Subdivision #4

Primary Limiting Factors:

extensive (charted) shallow waters in this area would promote examination of the subdivision for laser bathymetric surveys.

Secondary Limiting Factors: ice would limit use of the technique between 4 and 9 months each year,

water clarity is likely to be a limiting factor because of plankton (July-August) and high suspended sediment concentrations due to river runoff and wave or tidal resuspension: possibly a significantly limiting factor,

flight limiting factors would include snow (November-January), fog (July-August) and bird migrations (April-July: September-November).

Data Base and information Gaps:

bathymetric data is adequate to define shoal areas,

water clarity data is inadequate to determine feasibility of the survey method; this parameter is considered potentially limiting for this subdivision. 6.102 HUDSON BAY / 19,010 Region Total nearshore area c20m depth' km 2 LABRADOR #4 ( >1km from shore)

J F M A MJ JASOND II I II ■ II ■ ■■ MO0 BIOTA MN1 IIIMIN MI= OM I I

kelp beds * * * * — plankton bloom Ifie zo 111111111 11111111

ICE COVER a 1/10th (mean) VA /7" 7- II 1 M =1

PRECIPITATION 1 0 I I t

rain .FAEt /2122 1\ iy IN: * * * * --- IN! IN

snow 1

...-.

I I I I I I 111111111111111111 VISIBILITY I I 4 1 k m * * * :--- I

WATER CLARITY * * * * 777 7J ":%"7 _1:17. : L .—... I I I II WIND I .I■ WM I <2 knots I

> 20 knots * * * * IMBEllalMa=1111101111121111= I I= 1 ! thunderstorms pmralliq 72— Other: BIRDS * * * * 1111111111111111111

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data 111111111111111111111111111111/7/ZeZZ ■ Interpreted data nimmummimmiii9mmAm

Not applicable due to ice cover: * * * * 6.103

Region HUDSON BAY/LABRADOR COAST

Subdivision #5

Primary Limiting Factors:

few areas of sufficiently shallow water to permit extensive surveys,

the southwest coast of Baffin Island is not well charted but extensive shoal areas are unlikely to be present in this region due to general steep regional (onshore and offshore) relief.

Secondary Limiting Factors:

ice would limit operations between 4 and 9 months each year,

water clarity would probably be adequate, except during July and August due to plankton blooms; river runoff or coastal erosion are unlikely to result in high suspended sediment concentrations,

rooted vegetation may locally affect depth accuracy on rocky substrates and flight operations may be limited by fog (June-August), snow (October-December), and bird migration (June and September).

Data Base and information Gaps:

although data are limited for bathymetry and water clarity they are probably adequate for this regional evaluation. 6.104

HUDSON BAY/ 900 Region Total nearshore area c 20m depth: km 2 LABRADOR #5 ( > ikm from shore)

J FMA MJ J A SO ND

BIOTA LS m e1r 1-174- I 7777) kelp beds * * * *

plankton bloom - Vil 1E111111111 ICE COVER ■ le k 1/10th (mean) 11.11.111=1 Mr#∎ i IZEr E9 I 1 LI 6 1§11 11= 1 . II ki

PRECIPITATION 1=1 ! I 11 Fla 1 I

rain I 12' B= I n 1 i= E E

* * * * = -7 -t -- l snow --1 1 i I 11 .

I I= IS 1 I I I VISIBILITY 1Ni IS ■ ■ -- I I 1 I 1 I . 1

ill1711 . 4 1 km * * * * --

WATER CLARITY -- * * * * _ I F MilirnITIMIMr- - 1 1 I 1 1 I WIND ----• ,-..- II < 2 knots I -- 1

MM. MIN IN= =I ,== IMMI I N . k

N I i >20knots * * * * 1111111E1111111111 77; thunderstorms NM MOM 11=■ ■ =•11■1 0 ! I Other: ! BIRDS * IV I * * :::: I I

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data iii111111111m11111mirem

Extrapolated data 111111111111111111111111111111/###### AIM

Interpreted data min imminitimiymmiisommi

Not applicable due to ice cover: * * * * Region HUDSON BAY/LABRADOR COAST

Subdivision #6

Primary. Limiting Factors:

water depths are known to be less than 20 m over extensive sections of Ungava Bay.

Secondary Limiting Factors:

ice would limit field surveys between 4 (minimum) and 10 (maximum) months each year,

little is known about water clarity, other than the timing of the plankton bloom (July-August) but it is expected that suspended sediment concentrations would be high in shallow areas due to resuspension of fine-grained sediments by wave and tidal action,

flight operations could be limited by fog (July-August) and snow (October-January).

Data Base and information Gaps:

bathymetric data is sufficient to indicate that shoal waters exist but water clarity data is insufficient to assess the potential applicability of the technique: this parameter is considered to be potentially limiting for this subdivision.

6.106

HUDSON BAY/ 6,150 Region Total nearshore area c 20m depth: km 2 LABRADOR #6 ( >lkm from shore)

J FMA MJ J A SO ND

BIOTA i RI

kelp beds 7727171222 ra II * * * 1 - 72211INEW73AIMMI1 I plankton bloom

ICE COVER a 1/10th (mean) ! II NIS . kl I 1E 1 IF

PRECIPITATION 1- -I 2 . 11 I 1

rain 22-1 70., .— - IN L" I El * * * - E

_I I 1 1 11 snow l MN

II Ii II I II Il IEI NI II I 1= Ii II VISIBILITY I N IMM OM I = = II i i 4 1 k m * * * * 7E1 _...... •

WATER CLARITY * * * * ezzeinswiwrzeze #1 LI i II I ---- II •--- ...... WIND A 1111111111 i

< 2 knots ..... AS 10 NI 11011111

>20knots * * * * I 77 ?:./22. --- ....•

thunderstorms

Other: BIRDS * * * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data 1 111111 111 111111 111111111 111 11/'/Z/M

Extrapolated data immiimmimimilyzzizz#

Interpreted data imin inummlinmitntzzzzz -t.

Not applicable due to ice cover: * * * * 6.107

Region HUDSON BAY/LABRADOR COAST

Subdivision #7

Primary Limiting Factors:

few areas of water depths <20 m occur, these are generally discontinuous and scattered except for the area adjacent to Cartwright and in Lake Melville,

Secondary Limiting Factors: ice would limit field surveys for at least 4 and as much as 9 months/year,

plankton blooms would possibly limit the feasibility of the technique in July and September; suspended sediments are not considered to be a limiting factor, except adjacent to rivers which have a high sediment yield,

factors that would reduce flight operations include: strong winds or snow (November-March), fog (May-July), and bird migrations (May- June: October-November).

Data Base and Information Gaps:

although the data base is meagre for this subdivision it is sufficient for this regional evaluation. 6.108

HUDSON BAY / 3,728 km 2 Region Total nearshore area c20m depth: LABRADOR #7 ( > 1km from shore)

JFMA MJ JASOND II k I ! Is BIOTA E: I - . ' 1 kelp beds Mi1702ss I 1 iJ , * * * * ==" 1 I plankton bloom 1

MINIMS! ICE COVER a 1/10th (mean) ZO 11111111 pra 1. IZI N "ii I! II kl IS LI 1= 1 ! S PRECIPITATION E1 m

! i . I 1 a

rain i ! IN I u

I

* * * El snow

P 6 1E VISIBILITY RE - F A

* * * * ME Tiiiiiiii ; FM If 1511710 7 4 1 km

I. . :7117 711111311 111L WATER CLARITY —

* * * * . . 1 ---...:

WIND gi IE Ii I iE < 2 knots '177111n, I

iE

> 20 knots * * * * F 1751TIMITIIV7I IL - I . 1

....—.• 1 ! I

thunderstorms ------Other: •—.. BIRDS * 'IV :1— VII I ■ * * .1 , WM .

ITITUrMar

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data nu nit l trzzmz

Extrapolated data (11111111111111111111111111111 //////,

Interpreted data 111111111111111111111111111VZ/Zeir l

Not applicable due to ice cover: * * * *

'9 9 3HV 311 OO V S I 6.109

6.6 ARCTIC COASTS

6.6.1 Logistics

All coastal areas within the region are within the minimum transit time of three hours from a suitable landing site for an aircraft with an 8-hour fuel capacity. Although this is largely an unpopulated region there are a number of manned as well as unmanned airfields. The unmanned fields are unlikely to have fuel supplies but could be used as a temporary staging site.

Although all areas are within the minimum stipulated transit time, this assumes suitable flight conditions and that an alternate landing area would not be required.

6.2.2 Physical Geology

The arctic region is extensive in area but is not complex in its broad geological character. From the high mountain areas of Ellesmere and Baffin Islands, the geology becomes more simple and relief lower towards the west. Most of the arctic west of longitude 92 °W is made up of relatively unresistant bedrock that has been eroded by rivers, ice sheets and glaciers to form a complex lowland archipelago of islands and channels. The area of lowest relief extends from Foxe Basin west along the mainland coast, south of the Parry Channel.

Except for the southern Beaufort Sea, this area has been barely explored from a scientific or physiographic perspective. Although data for this region is scarce (subdivisions 6, 7, 8, 9, 16, 17, 20, and 21 on Fig. 6.8), the mapped areas with depths less than 20 m are in the order of 2 50,000 to 55,000 km (Table 6.7), a figure equalled only on a regional basis by Hudson Bay. There are undoubtedly extensive areas where water depths less than 20 m are found in Foxe Basin, the Gulf of Boothia, Queen Maud Gulf and Coronation Gulf. Perhaps as much as an additional 50,000 to Figure 6.8 Arctic Coasts subdivisions. Areas with solid shading are suitable for laser bathymetry; cross- hatch areas have water depths <20m, but are unsuitable due to poor water clarity. 6.111

Table 6.7 Arctic Coasts - Bathymetric Areas (subdivision boundaries are given on Fig. 6.8)

Subdivision Area with Depths <20 m (km2 )

1 * 2 >100 3 185 4 >252 5 >115 6 23,196 7 ? 8 ? 9 >153 10 85 11 630 12 415 13 * 14 * 15 * 16 * 17 >1,883 18 * 19 2,570 20 >3,350 21 24,886

TOTAL >57,820

* X11 months ice/year

(NOTE: actual total may be as much as 100,000 to 125,000 km2) 6.112

2 75,000 km , at a conservative estimate, of depths less than 20 m occurs in the area to the south of Parry Channel. North of, and including Parry Channel, water depths are greater and ice becomes a significant limiting factor (Section 6.6.3). Undoubtedly, suitably shallow waters exist in this region but, because ice limits ship movements in the area, little data is available on bathymetry except for a few isolated areas adjacent to logistic bases.

6.6.3 Oceanography

The wave climate in the Candian Arctic is limited by the presence of ice and short fetches, which, in general, are less than 300 km. Waves are usually less than 1 m in height and have short periods (2-4 s).

During the winter months, ice covers virtually all of the waters of the Arctic Archipelago. Break-up progresses slowly as the ice is moved through the channels to the east and south during late spring. The ice-free season is shortest in the northwest, and in these areas there may not be an open-water season in heavy ice years. Many of the channels and inlets of the northern and western arctic areas, as well as the Gulf of Boothia and parts of Foxe Basin, remain ice infested year round.

The range of tides in the Canadian Arctic region is highly variable. The largest tidal range occurs in the southeastern Baffin Island area where the mean tidal range is approximately 7 m. The range decreases towards the north to less than 2 m in the Lancaster Sound area and to less than 0.5 m along northeastern Ellesmere Island. To the west through Parry Channel, the tidal range decreases from approximately 2 m in the east to less than 0.5 m in the west. The entire western and southern Arctic, have tidal ranges less than 0.5 m. Throughout the Arctic the tides are semi-diurnal or mixed, mainly semi-diurnal.

The clarity of Canadian arctic waters is, in general, excellent. Except for localized effects during the period of excessive fluvial discharge in the spring melt, waters of the arctic region are very clear, owing to the reduced biological activity and low nutrient concentrations. 6.113

Plankton blooms are limited and of short duration in mid-summer. The main freshwater inflow from the Mackenzie River (average annual discharge of 3 -1 12,000 m s ) is heavily laden with suspended sediments, and the turbid plume affects a large area of the Beaufort Sea (Fig. 6.9). The other rivers draining into the Arctic are much smaller and lower in suspended sediment concentrations. Hence their affect on water clarity is very localized.

Bottom-anchored marine vegetation is essentially absent in shallow arctic waters due to ice scour.

6.6.4 Meteorology

The Arctic Coasts have a polar climate that results in cold air temperatures throughout the year and the formation of sea ice in winter months. During summer months winds are predominantly light and variable with the prevailing direction out of the westerly quadrant. The region is dominated by the effects of the Polar high-pressure system and cyclonic depressions are common but rarely intense. Strong winds (>50 km/hr) occur on the average only one or two days each month.

Fog may occur during the open-water season but this is not considered to be a significant limiting parameter. In terms of flight operations, local limitations may exist but there are no regional features that would be significant constraints.

6.6.5 Regional Analysis and Summary of Limiting Factors

The temporal variations of each of the limiting parameters are presented in the following tables for each of the 21 subdivisions of the Arctic Coasts. The spatial distribution of known shallow-water areas is summarized in Table 6.7 and shown on Figure 6.8 and at a scale of 1:3,500,000 on the map that accompanies this report. 6.114

Dominant Surface Flow

41. Dominant Bottom Flow

Primary Sediment Sink Secondary Sediment Sink

Figure 6.9 Sediment dispersal model for the southern Beaufort Sea (from Harper and Penland, 1982). 6.115

Areas of shallow water occur extensively in Foxe Basin, along the mainland coast, and on western Banks Island. In the areas adjacent to the Mackenzie and Koukdjuak Rivers, however, the sediment plumes would preclude laser bathymetry during the open-water season.

The region is ice-dominated so that open-water conditions are a primary limiting factor. Many sections of coast are uncharted, for example, the Gulf of Boothia, southern Queen Maud Gulf, and northern Foxe Basin, so that there exists probably double the actual charted areas with depths less than 20 m. This figure is considered realistic, but perhaps conservative.

Except adjacent to the two named rivers, water clarity is not considered to be significantly limiting. Biological factors do not promote plankton blooms and river runoff is limited in time and by small catchment areas. Some local areas of high suspended sediment concentrations would be expected at and adjacent to river mouths during the freshet. Little or no data are available, and one subdivision where the lack of data introduces an element of doubt is western Banks Island.

In the arctic region, laser bathymetry could be a valuable tool for reconnaissance surveys to define shoal areas in uncharted waters and to confirm or deny the presence of shoals in waters that are frequented during the navigation season. The technique has little applicability to the coasts of Baffin Bay, due to high regional relief, or to the islands north of the Parry Channel, because of the year-round ice cover.

The limited available or alternate airfields in the region would limit actual survey time in many areas of the arctic. In some cases, it may be necessary to establish fuel dumps at airfields to increase survey efficiency.

The major points that emerge from this analysis are as follows: • Ice is the primary limiting factor on the use of the system; in most areas, the mean open-water period is less than 3 months/year. 6.116

• North of the Parry Channel, year-round ice essentially precludes laser bathymetry.

• The areas with suitable water depths are primarily along the mainland coastal waters between the Melville Peninsula and the Yukon, and in northern and eastern Foxe Basin.

• Water clarity is not considered a limiting parameter except adjacent to the Mackenzie Delta and the Koukdjuak River, and possibly along the west coast of Banks Island.

• Many potentially suitable areas for laser bathymetry are presently uncharted.

• Logistics may be a significant factor for survey efficiency as travel times to and from the area may limit the available time for actual survey work. 2 • In this region, approximately 100,000 km has been estimated to have water depths less than 20 m and open-water conditions for at least one month/year; of this total, 75,000 km (75%) is expected to be suitable for laser bathymetry during the open-water season.

ARCTIC COASTS Region #1 Subdivision

Primary Limiting Factors: mean ice cover >11 months/year,

in "good" years, may be open-water for a maximum of 4 months in some sections,

steep coast, probably few shoal areas with depths <20 m.

Secondary Limiting Factors:

water clarity would probably not be a limiting factor, except adjacent to fjord-head deltas or glacial streams during the freshet (August).

Data Base and information Gaps:

ice data adequate, but little or no information on bathymetry or water clarity. 6.118

Region ARCTIC COASTS Total nearshore area c 20m depth • * km 2 #1 ( >1km from shore)

J FMA MJ J A SOND BIOTA kelp beds * * * * * * * * . . plankton bloom ICE COVER ICE COVER ALL YEAR a 1/10th (mean)

PRECIPITATION 1 II rain

* * * * El * * snow

—II

VISIBILITY If _- - 4 I [11111n11111rirl * * * 1 k m * * * * *

WATER CLARITY * * * * * — * * * — 1 1=-2 1 1= e=- 11- g = WIND =1

< 1 • 11 1 I 2 knots 1

-1 gl ■ Il I =1 * * * * * -• * *

>20knots

thunderstorms - Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111 11 111111111 11 1111111 V/7171/74■111111111•1

Extrapolated data 111111111111111111111111111111 177./M

Interpreted data 111111111111111111111111111VM 1

Not applicable due to ice cover: * * * * ARCTIC COASTS Region

Subdivision #2

Primary Limiting Factors: mean ice cover >11 months/year,

in a "good" year, may be up to 6 months of open water in some sections,

few known areas of shallow depths, because of high coastal relief there are probably few additional shoal areas.

Secondary Limiting Factors: water clarity would probably not be a limiting factor, except adjacent to fjord-head deltas or glacial streams during the freshet (August).

Data Base and information Gaps:

ice data adequate, but little or no information on bathymetry or water clarity. 6.120 ARCTIC COASTS >100 Region Total nearshore area ic20m depth • km 2 #2 ( > 1km from shore)

J F MA MJ J A SOND BIOTA MMMMM ...... • •... MMMMM kelp beds * * * * * * _ plankton bloom ICE COVER at1/10th (mean) ■ i PRECIPITATION I I I I

rain IA ; . I

* * * .=

* I * * snow I I i 11

VISIBILITY

4 1 km * * * * -llg illy II uill1171111m17 * *

WATER CLARITY * * * * 1111111111111111111111 11111111 * * IIIII Ina s= a WIND < 2 knots --. -••••••1 11 110011010111 111— ual 1 uititli 1 e= • N -41 =1 mil

> 20 knots * * * * 0101711101 la * * thunderstorms Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11 111111111111 1111 11 111111111 10W

Extrapolated data imminimmummily######

Interpreted data 1011111 1111111111111 11111Zemm

Not applicable due to ice cover: * * * *

Region ARCTIC COASTS

Subdivision #3

Primary Limiting Factors:

few areas of shallow waters, as this is predominantly a region of high relief: some lowlands on east Devon and south Bylot Islands.

Secondary Limiting Factors:

mean open-water season is 2 months,

water clarity would be good, except adjacent to fjord-head deltas or glacial streams during the freshet (August): the lowland coasts of east Devon and south Bylot Islands have numerous glacial streams with high suspended sediment loads,

bird migrations are a significant factor during July and August.

Data Base and information Gaps:

ice data adequate and regional bathymetry reasonably well- known: no data on water clarity. 6.122 ARCTIC COASTS 185 Region Total nearshore area .c 20m depth • km 2 #3 ( >1km from shore)

JFMA MJ JASOND BIOTA kelp beds * * * * * * M1111111111111,4/77%; * * ...... plankton bloom ■ ...... ICE COVER 2.1/10th (mean) MINIMINNIMUMNIMW4 tat 1- ■ PRECIPITATION ■ IIIMOO rain ; t * * * * * * I "-- * *

snow I rl MIT

Ii I VISIBILITY ! I I I * * * * * * 1 * * 4 1 k m

WATER CLARITY * * * * * * =ImE,...... ---__ * *

WIND !g I-A

< 2 knots F! FA Ei II !

>20knots * * * * * * * * thunderstorms ii 1 IS iS Other: 1 , i i

BIRDS

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data iiiiiitmunnisimili rzzzzzezjiliii■

1•=1 Extrapolated data IIIIIIII I IIIIIIIII I IIIIIIIIII I /ZIZM

Interpreted data IIIII1111111111111111111111 iemmow■ 7

Not applicable due to ice cover: * * * *

ARCTIC COASTS Region

Subdivision #4

Primary Limiting Factors:

few areas of shallow waters; this is a region of high relief and fjords with only restricted sections of lowland coast.

Secondary Limiting Factors:

mean open-water season is <2 months, therefore, only a narrow operational window,

water clarity would be good, except adjacent to fjord-head deltas or glacial streams during the freshet (August).

Data Base and information Gaps:

data base generally adequate for this evaluation. 6.124 ARCTIC COASTS Region Total nearshore area c 20m depth • km 2 #4 ( > 1 km from shore)

J F MA I1J J ASOND !N! NI 1= II 1= i BIOTA t]

* * * * 1.111111111, 1 1

* kelp beds * * I

- plankton bloom /1771 41111111111 ICE COVER 1/10th (mean) 7# Tr 1E- PRECIPITATION ii [ 1 - El

rain * .-- 10 a * * * * * * ■ * IMMI N , snow ! --- VISIBILITY 1km * * * * * Firinrair!! Iva * *

WATER CLARITY * * * * * 77ziAlwAiiiiiiiii * * iI E! WIND <

2 knots

' !•

* ! I 1 >20knots * * * * !! * *

thunderstorms i

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 V'ZZIZZI/P1111■1

Extrapolated data 111111111111111111111111111111 zz,zzeinmommi

Interpreted data

Not applicable due to ice cover: * * * * ARCTIC COASTS Region

Subdivision #5

Primary Limiting Factors:

few sections of coast with suitable water depths: a region of high relief in the backshore except at the heads of fjords.

Secondary Limiting Factors:

mean open-water season is 2 months,

fog and rain may limit operations in July and August,

water clarity would be good, except adjacent to fjord- head deltas or glacial streams during the freshet (August): some resuspension of fines would be expected in areas of high tidal range and mudflats (e.g., Frobisher Bay).

Data Base and information Gaps:

data base generally adequate for this evaluation.

6.126

>115 km Region ARCTIC COASTS Total nearshore area c 20m depth • 2 #5 ( >1km from shore)

JFMA MJ JASOND [ RI BIOTA . K1 11 . kelp beds * * * ' .

_ plankton bloom Al ZIIIIIIIII - MMMMM MO IIII • e MI l ICE COVER 1 / 10th (mean) , /I _ 4 Milii Fr PRECIPITATION IS! I 1

rain —"—s ami ir if !N 1 LE 1f * I I =1 T f

snow ! ' 1 TF17111111 I

, I

1= la i= 111 1S 1E 1-1: VISIBILITY -.1 , -77 a 7 - - -1 1 1 i j <1km * * * 1 FilMirt i . . PMFInq

WATER CLARITY * * * ..:7.....-.... . WIT FE El WIND 0

< 2 knots 1 - 1111g Er Pi Fi Ef- 0 *I z

>20knots * * i -

thunderstorms

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1111111111111111 11 1111 1 1111111/Z/ZZ/d'AMISIMIIIIN

Extrapolated data

Interpreted data mil mum ow inintim### rt Not applicable due to ice cover: * * * * ARCTIC COASTS Region

Subdivision #6

Primary Limiting Factors:

extensive uncharted areas of shallow waters, particularly on east and north coast of Foxe Basin: sections of southwest coast (e.g., Lyon Inlet: Winter Island: Vansittart Island) are also uncharted.

Secondary Limiting Factors:

mean open-water season is <2 months,

water clarity probably not a significant limiting factor except adjacent to streams and rivers during the freshet (August): probably limiting off the coast of the Plain of Koukdjuak due to high stream and river sediment loads,

bird migrations could be an operational factor in August.

Data Base and information Gaps: data base inadequate for even a regional assessment: little or no bathymetry in most areas and no water clarity data. 6.128 ARCTIC COASTS 23,196 Region Total nearshore area %20m depth: km 2 #6 ( >1km from shore)

JFMA MJ JASOND i I I ! BIOTA ..... —• , • I i

kelp beds , * * * * _ plankton bloom pilaf rad wowed, 111111111 iiiiiirbuilit ICE COVER a 1/10th (mean) ilmoviimmi 11P I I 117 PRECIPITATION ej .1 * *77171 ! I 1

* rain * MU RI I ' p snow :

a,2

lE° 1- I VISIBILITY 1-7 =1 .7 =1 =1 4 1k m * -1 * * *

1117 iiiiUM MI

WATER CLARITY * 17177* 11111111W/WZI1111111111111111111111111111 * * 111F, MINDMINIMIMIMM ii i l WIND 1

< 2 knots !;1I 1. 12:2:7 71M I * * * * ii >20knots . ..":1 iT I =ME E 1

thunderstorms MEll

Other: I --

BIRDS * * * * I --

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data iiiinnoti mitormmzssmstoM

Extrapolated data Hnimmmimmuiywzzzem■

Interpreted data 111111111111111111111111111111/#####

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #7

Primary Limiting Factors:

ice is usually present year round in this region: in a "good" year, there may be open-water conditions for up to 3 months,

extensive uncharted areas: sections of Committee Bay, Pelly Bay, Lord Mayor Bay, and Brentford Bay are uncharted and possibly have shoal areas as these are areas of low relief.

Secondary Limiting Factors: water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.130

ARCTIC COASTS ? Region Total nearshore area c 20m depth: km 2 #7 (> 1km from shore)

JFMA MJ JASOND BIOTA . kelp beds * * * * * * ' * * _ plankton bloom 111111111 Z4111111111

ICE COVER ICE COVER ALL YE R a 1 /10th (mean) ! PRECIPITATION I rain * * * * * * * * * 1T snow VISIBILITY c 1 km * * * * * * * MEM 171711 * *

WATER CLARITY * * * * * * * 11.22M1 * * II 1 1I ! WIND i I 1 II I

< 2 knots 1 jEl a! I 1E * * * * * * * E9 =1 * * 1 1 i >20knots .

. I 1 thunderstorms

I Other: I BIRDS * * * * * * I * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ ■ Published data IninnitimitintimormmAm

Extrapolated data miiimiminmilluffedzifim■

Interpreted data 1111111111111111111111111 ntremm

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #8

Primary Limiting Factors:

mean ice-free season is usually <2 months,

extensive uncharted areas: sections that may have extensive areas with depths <20 m include Browne Bay, Wrottesley In- let, and northeast King William Island.

Secondary Limiting Factors: ice is the most critical limiting factor: in a "good" ice year, the open-water season may be as much as 3 months,

water clarity is not considered to be a limiting factor except adjacent to streams and rivers during the freshet (August).

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.132 ARCTIC COASTS Region Total nearshore area c 20m depth: km 2 #8 ( >1km from shore)

J FMA MJ J A SOND

BIOTA - kelp beds * * * * * * * '— --- * * _ plankton bloom EMI ICE COVER a 1/10th (mean) 0111111■1■11111.11111.11110/ - lE i= Ii iii !

PRECIPITATION ! * i .

rain

* * * * * * i * * snow I I ■ VISIBILITY I

<1km * * * * * * * FIR i * *

WATER CLARITY * * * * * * * WE= * *

..— WIND < 2 knots MIN NM NUM =I 1 I >20knots * * * * * * * ' M * thunderstorms

-11-

Other: 1 11

BIRDS * * * * * * * .

- * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+ ■ Published data 1111111111111111111 1111111111VZ/ZZ/Z41 111=11

Extrapolated data ilomminimmiymmmo■N

Interpreted data 11111111111111 1111111111111111"/MMA

Not applicable due to ice cover: * * * *

ARCTIC COASTS Region #9 Subdivision

Primary Limiting Factors:

ice cover is usually present year round with <1 month/year of open water,

extensive uncharted areas: some sections that might have shoal areas are Bernier Bay and Cresswell Bay.

Secondary Limiting Factors:

open-water may exist for up to 5 months during a "good" ice year,

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.134

ARCTIC COASTS >153 Region Total nearshore area gc 20m depth • km 2 #9 ( >1km from shore)

J FMA MJ JASOND I II I I I I I I BIOTA -- -- I I kelp beds * * * * * * * _ plankton bloom 11111111111111111W 111111111 ICE COVER a1/10th (mean) * * * * *1.1.1=Ml * 1 I i ! I I I 1 1 1-= 1= - -1

PRECIPITATION 1 .1 11 I

1 rain =

* * * 1 ! 1- 1= 1 F * * 11= *

51 * - =1 .. 1 1 1 1 1 1

snow

I I I I VISIBILITY . --- I I 1 km * * * * * ,—°- I * *

WATER CLARITY * * * * * 111111111111111111 Z111111111 * *

WIND ,

< 2 knots 1 1mi 1 - 7- f- ± 1 1 * * >20knots * * * * i I I • ! thunderstorms

• II OEM IMM • ■ • ■ . Other: --- BIRDS * * * * * * -- *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 V7Z/Z.,,,41•1111111111111MI

Extrapolated data limmimmitimininymmAmm■

Interpreted data 11111111111111111111111111111

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #10

Primary Limiting Factors:

few areas with extensive shoal (<20 m) water: potential shallow areas are northern Steensby Peninsula and Jungersen Bay-Berlinguet Inlet.

Secondary Limiting Factors:

mean open-water season is <3 months/year: up to 5 months in a "good" ice year in some sections,

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps: data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.136 ARCTIC COASTS Region Total nearshore area "20m depth: 85 km 2 #10 ( >1km from shore)

J FMA MJ J A SOND Litt I _LA I. II BIOTA II kelp beds

1 * * * * * 1 * 1 -

plankton bloom 1 ICE COVER a 1/10th (mean)

PRECIPITATION 111111111111111111 rain * * * * * * * snow 111111111 11111111111111111 VISIBILITY 4 1 k m * * * * * * *

WATER CLARITY * * * * * 111111111 * * II 0 Ur uI - WIND - - -

<2 knots • "

I I E lI 61 = = 21 7 - l 1 * * * 1 11 * * ! >20knots * * II I

thunderstorms

Other: --- ____ BIRDS * * * * * ' _Zell * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data itinnimilininintimorzzzzzzzisa■

Extrapolated data linimilinimmuivezzz#,Rwsi■

Interpreted data

Not applicable due to ice cover: * * * * 6.137

Region ARCTIC COASTS

Subdivision #11

Primary Limiting Factors:

open-water season is usually <2 months/year,

few extensive areas of shoal waters: uncharted sections that may have extensive areas with depths <20 m include Allen Bay, Erebus Bay, and the northeast coast of Wellington Channel: some shoals exist in the region (e.g., near Lowther Island) and these could be charted.

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps: data base poor but adequate for a regional assessment. 6.138 ARCTIC COASTS 630 km Region Total nearshore area ic20m depth- 2 #11 ( > 1 km from shore)

JFMAMJJASOND H I BIOTA •MOU

kelp beds I NIMINEN =====

* * * lllllllllll ."'n * *

plankton bloom 0111•1•SI ICE COVER ?.. 1 / 10th (mean) 111110.1.1.11.11M7179

PRECIPITATION rain 1111111111 1111111111111111111 * * * * * * snow 11111111 111111111 11111111111111111 le/

VISIBILITY ..... ------la' —...... * * * * . 1111111111 111111111 111111111 __ * * 4 1 k m

WATER CLARITY if * * "--MirlW * *

WIND < 2 knots

> 20 knots * * * * 1011111111111111-111111111111111111H1111111[111111111[I [1- * *

thunderstorms Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data

Interpreted data 111111111 111111111111111 1 111111######

Not applicable due to ice cover: * * * *

Region ARCTIC COASTS

Subdivision #12

Primary Limiting Factors:

region of high relief: few areas where extensive shoals would likely exist, other than at heads of bays or fjords.

Secondary Limiting Factors:

open-water season is generally <2 months/year,

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base poor but adequate for a regional assessment. 6.140 ARCTIC COASTS 415 Region Total nearshore area 20m depth •• km 2 #12 ( >1km from shore)

J FMA MJ JASOND I II 1 II II II II BIOTA M 1 I kelp beds 11 * * * * P ' " " * * plankton bloom ..... )111111111rIAMege 111111111 ICE COVER 2.1 /10th (mean) IIJji [ 1 = igl ! I 1E lE I

PRECIPITATION E I i I 1 I iI 1

rain * * * * * * g : II PI

snow I I

1= VISIBILITY 1E .1 II I 41km 1 1 * * * * 727iiiiTIMITIT7 I

* *

WATER CLARITY * At * * — 11111171 * *

WIND 1E IE1

< 2 knots iriMq .

F _-- - >20knots * * * * Lull 1 * * thunderstorms

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data ■ ■ Interpreted data imimmimmilmillitifz#, ##40 1

Not applicable due to ice cover: * * * *

ARCTIC COASTS Region

Subdivision #13

Primary Limiting Factors: ice cover is usually >11 months/year,

few areas where shoal waters are known or are likely to exist.

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.142

Region ARCTIC COASTS Total nearshore area .c 20m depth: km 2 (>1km from shore) #13

J FMA MJ J A SOND

BIOTA kelp beds * * * * * * * * * _ plankton bloom .— .— -- ICE COVER IC C • VE . A L Y AR a 1/10th (mean) ! ri I PRECIPITATION I I. I i I rain _ * * 1 i N * * * * * * I N snow

v.- I--I 1

VISIBILITY - - .. 1 * * * 4 1 k m * * * * * *

WATER CLARITY * * * * * . .... * * * PI I la gl ICI WIND < 2 knots l 1 ! I

. i i > 20 knots * * * * * * -— 1 * * thunderstorms Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 11111111111111111111111111111 1,7,7/1/41111=11111■1111•

Extrapolated data Minimmuminlymmin■m

Interpreted data 111111111111111111111111111111,M,

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #14

Primary . Limiting Factors:

mean ice cover >11 months/year,

many shoal areas are known to or are likely to exist as this is a lowland region with gentle onshore and offshore relief in most sections.

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.144

Region ARCTIC COASTS Total nearshore area c20m depth' km 2 #14 ( >1km from shore)

JFMA MJ JASOND

BIOTA kelp beds * * * * * * * * _ plankton bloom ...... OOOOO ICE COVER ICE COVER ALL YEAR a 1/10th (mean) I FA 11 t!

PRECIPITATION •"* -7 1 1 rain * * * * * * * * 1= I

snow 1 1= VISIBILITY 1.1 -= 4 1 k m * * * * * * EFIEFE -1 * *

WATER CLARITY * * * * * * 1 ...L7711121--- * * r7 I WIND 1 VIM I■11 I■ I VA

< 2 knots , >20knots * * * * * * mum * * 1 1 thunderstorms . .1

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data UWE

Interpreted data

Not applicable due to ice cover: * * * *

ARCTIC COASTS Region #15 Subdivisio n

Primary Limiting Factors: mean ice cover >11 months/year,

some shoal areas are known and are likely to exist in lowland sections (e.g., Byam Martin Island).

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.146

Region ARCTIC COASTS Total nearshore area %20m depth: km 2 #15 ( > lkm from shore)

JFMA MJ JASOND BIOTA -- --- kelp beds * * * * * * ---- * plankton bloom • m

ICE COVER ICE COVER ALL YEAR a1/10th (mean)

PRECIPITATION rain I * * * * * * * * - I El a --

snow I 1 i

-- l .-- l 10 1= .. I VISIBILITY i II i ■...■ . I 1 l I * * * * * * 1 * * 4 1 km —. i

WATER CLARITY * * * * * * _11111ffi . * * Ii ! I ., WIND I ---

< 2 knots i

:ff F . * * * * * * IA _ * * 1 - 1 >20knots Mil - thunderstorms Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 1111 1 1111111111 1111111111 1111 eZA 111.■ 11111.1

Extrapolated data Inlunnnlnnlllnnlnn IZZM

Interpreted data 111111111111111111111111111V######

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #16

Primary Limiting Factors:

mean ice cover >11 months/year,

shoal areas are known or are likely to exist in many sections as this is a lowland region: probable areas with depths <20 m include Ommanney Bay, Gateshead Island, Royal Geographical Society Islands, Erebus Bay, and Albert Edward Bay.

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.148 ARCTIC COASTS Region Total nearshore area c20m depth km 2 #16 ( > 1km from shore)

J FMA MJ J A SOND BIOTA . - kelp beds * * * * * °— 'I* * * ■ MO WPM= EMI. MMMMM plankton bloom ICE COVER ICE COVER ALL YEAR a 1/10th (mean) I PRECIPITATION im IA rain * * * * * * 1 * * 1 i

snow 1

VISIBILITY 4 1 k m * * * * * * EIZEMIZIEEN * *

WATER CLARITY * * * * * * =11111711111: * * 1 1 WIND 1 ..., II i < 2 knots i * * * * * * • — * * 1 1 >20knots 1 1 ; I thunderstorms I Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data mimilminiminmovizz,74■■

Extrapolated data

Interpreted data 1 i111 1 1 1 Il11111111111111114ezzeizz,■=

Not applicable due to ice cover: * * * * 6.149

ARCTIC COASTS Region

Subdivision #17

Primary Limiting Factors:

ice-free season is usually <3 months/year,

many areas with shoal water are known or are likely to exist as this is a lowland region: probable areas with depths <20 m include: the Nordenskiold Islands, Royal Geographical Society Islands, the mainland coast from Simpson Strait to Melbourne Island, Cambridge Bay, Melville Sound, and Bathurst Inlet.

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. ,—

6.150 ARCTIC COASTS Region Total nearshore area c 20m depth - >1 9 883 km 2 #17 ( > 1 km from shore)

J FMA MJ J A SOND I I I BIOTA I —. I I I

kelp beds * * * * * * *

_ plankton bloom VAIMffe111111111 1 ICE COVER 1/10th (mean) . I

PRECIPITATION • I I .

rain 1 I N

* . * * * * * * I E N

snow -1 • I . VISIBILITY 4 1 k m * * * * * * Dianoto M -__ *

WATER CLARITY * * * * * * /74 VAIIIMII17- *

WIND <2 knots 1. 'EN g .= * * * * * * 72 . l

>20knots mim * . I !

thunderstorms

Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data IIIII111111111111110mIrzzzzezzmiiiimmoim

Extrapolated data im11111111111111 111111111111 ######

Interpreted data

Not applicable due to ice cover: * * * * ARCTIC COASTS Region

Subdivision #18

Primary Limiting Factors:

mean ice cover >11 months/year,

few shoal areas are known or are likely to exist: the only extensive area is in Richard Collinson Inlet (approx. 500

km2 ).

Secondary Limiting Factors:

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base inadequate except for a very general regional assessment: little or no bathymetric data in many areas. 6.152 Region ARCTIC COASTS Total nearshore area c20m depth - * km 2 #18 (>1km from shore)

JFMA MJ JASOND

BIOTA . OOOOO ...•..•.- kelp beds * * * * " "— — * * MMMMMM MIMOMMIIIMINOMMI MMMMMMMMMMM pl ankton bloom i

ICE COVER ICE COVER ALL YEAR 21/10th (mean)

i ! *E k! ! PRECIPITATION ! 1 j rain * * * * 1 * p snow HIE VISIBILITY 1 : IE * E q =

* l 4 * 1 k m * pump * *

WATER CLARITY * * * * ....-77....7 -7311111E33.17 * * I i WIND <2 knots I ! i' RI E.

>20knots * * * * ME= ] * * thunderstorms Other:

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+ Published data Immo' 'm ini litinirzywiezp■i

Extrapolated data 11111111111111111111111111 19/MM I

Interpreted data limmininummimm mMA■li

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #19

Primary Limiting Factors:

ice-free season is usually <1 month/year,

extensive shoal area on west Banks Island.

Secondary Limiting Factors:

water clarity may be poor along this coast due to numerous streams and rivers; aerial surveys indicate that this poor clarity is generally limited to within bays and lagoons.

Data Base and information Gaps:

data base inadequate for even a regional assessment: little or no bathymetry in most areas and no water clarity data. 6.154 Region ARCTIC COASTS Total nearshore area ic 20m depth - 2,570 km 2 ( > 1km from shore) #19

JFMA MJ JASOND

BIOTA kelp beds

. I MIMMIIMMIN• ■••••■•1 MMMMMMMMMMM ankton bloom pl ,.... t. . ...... ICE COVER a 1/10th (mean) lall...11.1 it reE 1 I I

PRECIPITATION l I I

rain t ! i :

* * * * * * 67i uNT

snow 1 11••■■1

VISIBILITY MR17111111 IN' IN! ism * * * * Nrigna * *

<1km

WATER CLARITY * * * * =WIIIIII * *

WIND <2 knots > 20 knots * * * * lijimargirmarer II I j * *

thunderstorms --- -- Li 11111111 1 •_.

Other: E -1 BIRDS * * * * ..• * *

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111111111111111111/ZZ/M

Extrapolated data MIN 1■11■1 ■ 11•111.11■ =NM

Interpreted data n11111111ummiln 111[1 1mm

Not applicable due to ice cover: * * * * Region ARCTIC COASTS

Subdivision #20

Primary Limiting Factors:

few extensive areas with shoal waters are known or likely to exist: areas where depths <20 m exist include: the Parry Peninsula, north Simpson Bay, Dolphin and Union Strait, and Austin Bay.

Secondary Limiting Factors:

open-water conditions usually occur for <4 months,

water clarity may be affected adjacent to streams and rivers during the freshet (August), but otherwise water clarity would be expected to be non-limiting.

Data Base and information Gaps:

data base poor but adequate for a regional assessment. 6.156 Region ARCTIC COASTS Total nearshore area c 20m depth: >3,350 km 2 ( > 1km from shore) #20

JFMA MJ JASOND [ I ! II

BIOTA kelp beds . ---. . I *

* * * * 1 UMW.. _ plankton bloom .....• IIIIIIIHK/AlwAmmill ICE COVER a 1/10th (mean) zo ',/, 411 III =

PRECIPITATION rain * * * * 111111111 * snow 111111111 11111111k#441111111

VISIBILITY 11== II 4 4 1 k m * * * * MEll Innm prir-- *

WATER CLARITY * * * * 1 1 11 1 • 11111111 *

WIND < 2 knots IIIIIIII r 111111111 71171r 1= 1E l ri ll - -

>20knots * * * * I 1719. 1 1 * ' !

thunderstorms I II Other: II ! I II BIRDS * * * *

*

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH: RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data

Extrapolated data niumminninitymm■m■

Interpreted data n11111m1111111111111111111timmi■m

Not applicable due to ice cover: * * * * ARCTIC COASTS Region

Subdivision #21

Primary Limiting Factors:

extensive shoal areas characterize most of this coast.

Secondary Limiting Factors:

ice-free season is usually 2-3 months/year,

the Mackenzie River sediment plume would limit water clarity during the open-water season throughout much of this region, except the Yukon coast and Liverpool Bay; in these areas water clarity may be non-limiting except adjacent to rivers and streams during the period of river flow.

Data Base and information Gaps:

data base adequate for this level of regional evaluation. 6.158 Region ARCTIC COASTS Total nearshore area ic 20m depth • 24,886 km2 121 (>1km from shore)

JFMA MJ JASOND I II i I I BIOTA I i 1

kelp beds * * * * ' — '

- plankton bloom :MO rjh IVAIIIWIA 111111111 ICE COVER a 1/10th (mean) .II.

PRECIPITATION rain 111111111111111111 111111111 111111111 * * * * snow [11111111 1111111111111111111111111111 I I VISIBILITY N=I 1111111111E1111 IMMIldi .77. 4 1 km * * * * *

WATER CLARITY * * * * *

WIND I - -- -- i < 2 knots 1 — — - I

I 1

* > 20 knots MEM WOO NM .111= MI

■■ •■ NM IIIIIM MI thunderstorms ------Li

Other: BIRDS * * * * 171 17111 , : * 1

LEGEND: PARAMETER FREQUENCY WITHIN THE MONTH:

RELIABILITY: 1-6% 7-33% 34-66% 67%+

Published data 111111111111111111111111111111WW

Extrapolated data 111111 1111111 111111111111 11111V/ZM ■I, MIMI, IMO INI.M. =NI

II Interpreted data 111111111111 1111 11111111111V/Z/M

-r Not applicable due to ice cover: * * * *

7.0 ANALYSIS OF RESULTS

At the outset of the study, an item of concern that became immediately apparent was that the data base would, in most areas, not be adequate for an accurate analysis. By the completion of the project, this concern was no longer considered to be significant. With the exception of a few areas, for example, Banks Island and Queen Maud Gulf, the data base was adequate for this level of regional analysis. In only one region, the Great Lakes, is the data base sufficiently detailed to permit a rigorous analysis (Section 4.5).

The three primary (permanent) limiting factors of water depth, year-round ice, and distance from an airfield were considered first in the analysis. Areas that met the three criteria were mapped and measured. The distance parameter was found to be non-limiting. From this first phase, it was evident that there existed significantly large areas with suitable conditions to warrant further analysis. In particular, in Hudson Bay and 2 the Arctic, over 100,000 km were identified (Table 7.1), and these areas were primarily extensive and continuous (southern Hudson Bay/James Bay: Foxe Basin: southern Beaufort Sea). The three areas listed above accounted 2 2 for 83,000 km of the 109,000 km in these two northern regions: this figure is almost half of the total area with water depths less than 20 m for all of Canada. Other extensive areas that met the three primary criteria included the lower Great Lakes (south Huron: St. Clair: Erie: 2 Ontario) and the southern Gulf of St. Lawrence. In total, 170,000 km were identified as having depths less than 20 m and mean open-water (ice-free) conditions for at least one month each year. Of the uncharted areas of 2 Hudson Bay and the Arctic, an additional estimated 10,000 and 40,000 km respectively was considered to probably have water depths less than 20 m (Table 7.2). The area of depths less than 20 m is approximately 6 percent of the Canadian shelf (depth less than 200 m). 7.2

Table 7.1 Summary of Bathymetric Data

AREA AREA LENGTH OF REGION <200m <20m COAST

Pacific Coast 77,138 km2 8,556 km2 25,717 km Great Lakes - 18,039 9,471 Atlantic Coast 1,652,802 34,497 45,369 Hudson/Labrador 1,013,341 >51,288 30,938 Arctic Coasts 808,080 >57,820 142,012

TOTAL 3,551,361 >170,200 253,507

Table 7.2 Summary of the Results

h Estimated Area Estimated Area Per Cent of Per Cent of Region with Depths <20m with Depths <20m Regional Area Canadian Total (km2 ) and Suitable Water Suitable for Suitable for Clarity (km2 ) Laser Method Laser Method

Pacific Coast 8,500 7,800 90% 6.4% Great Lakes 18,000 6,000 33 5.0 Atlantic Coast 34,500 17,500 51 14.4 Hudson Bay/Labrador 60,000 15,000 25 12.4 Arctic Coasts 100,000 75,000 75 61.8

221,000 km2 121,300 km2 R 55% 100% 7.3

The association between shallow water depths and regional geology is relatively simple. On the Pacific coast, mountain building has resulted from regional (plate) tectonics and the shelf is narrow. The Atlantic, Hudson Bay, and arctic regions have lowland coasts, except along the Labrador-Baffin Island-Ellesmere Island fringe. In general, areas of low backshore relief have a wide shelf with extensive shoal areas, whereas on coasts with high relief due to past or present mountain building (tectonic) activity, the shelves are narrow with few extensive shoal areas.

The major lowland regions of southern Canada are characterized by a mantle of glacially deposited sediments. The erosion of these deposits by rivers or directly by coastal processes introduces considerable volumes of suspended sediments into the nearshore waters. In the analysis of the limiting parameters; water clarity became the most significant of the secondary (temporary) factors. The presence of suspended material, either sediment or plankton, or the presence of marine vegetation, would limit the feasibility of the laser bathymetry technique. The contrast between clear and turbid waters is most obvious in the Great Lakes region. The bare, resistant Shield rocks of the upper lakes yield little sediment and the waters are generally clear. In the lower lakes, although water depths are shallower, erosion of the unconsolidated cliffs and river inputs produce high suspended sediment concentrations that would generally preclude use of the laser system. Thus, in the Great Lakes region, the technique would be 2 feasible for only 6,000 of 18,000 km with depths less than 20 m (Table 7.2).

The major sources of suspended material are plankton blooms, river runoff, coastal erosion and sediment resuspension (by waves or tidal currents). The intensity of these biological and geological processes decreases to the north, so that in many arctic or subarctic areas the waters are generally clear, even though the shore zone and backshore may be characterized by a mantle of unconsolidated fine-grained sediments. In these areas, high sediment concentrations would usually be limited to waters adjacent to streams or rivers during the short summer melt season. 7.4

In addition, in arctic rivers much of the material is transported as bedload rather than in suspension, due to arctic weathering processes that generally produce coarser sediments than in lower latitudes. The two primary exceptions are the waters adjacent to the Mackenzie Delta (which has an extensive and well-documented sediment plume) and to the Plain of Koukdjuak (which is presumed to have a high sediment yield). In southern Canada, areas of poor water clarity, other than the Great Lakes, are the Fraser Delta (because of river-borne sediments), the southern Gulf of St. Lawrence (because of coastal erosion and river runoff), the St. Lawrence estuary, and the Bay of Fundy (both due primarily to sediment resuspension).

Of the seven areas that have the most extensive shoal waters (lower Great Lakes: southern Gulf of St. Lawrence: southwest Hudson Bay: James Bay: Ungava Bay: Foxe Basin: southern Beaufort Sea) and that have a 2 combined total of over 110,000 km of depths less than 20 m, only the northern part of Foxe Basin is considered to have a level of water clarity that would be acceptable for the laser technique. Thus in the Great Lakes, Atlantic, and Hudson Bay regions, only an estimated 33, 51 and 25 percent respectively of the areas with depths less than 20 m would be suitable for laser bathymetry (Table 7.2).

In terms of the overall distribution of suitable areas, more than 60 percent of the areas that are considered suitable for laser bathymetry 2 occur in the Arctic (Table 7.2). Approximately 30,000 km are areas of known (i.e., charted) water depths, with the balance made up of areas in uncharted waters that are believed to have shallow waters. The regions of Hudson Bay and the Arctic Coast have an estimated (conservatively) 75,000 2 km of suitable waters with depths less than 20m. There are probably few areas in the world where similar extensive shoal areas exist. The present data base in this area is very limited and, in some sections non-existent. An option to be considered is the applicability of the laser bathymetric technique for reconnaissance surveys in these extensive uncharted waters. This type of survey would perhaps not meet the same depth and position accuracy standards as demanded by normal hydrographic survey practices. 7.5

Such a relaxation of standards could be considered in light of the advantages of obtaining reconnaissance bathymetry data versus the possibility of little or no data if a conventional ship-oriented survey programme is designed for the region.

The primary technique that exists for the collection of hydrographic depth data is sounding, using either a ship or launch as the platform for the echo-sounder. This survey operation is relatively slow when large areas are to be surveyed, and can be limited by weather, sea state or ice conditions. Laser bathymetry has certain advantages in terms of operational efficiency; an aircraft can travel at speeds up to ten times faster than a ship or launch.

A maximum allowable error of 30 cm is used as the standard for depth data. This assumes that positioning techniques for the location of flight lines, or ships tracks, are suitably accurate. Any substantive deviation from a profile line could result in data that are accurate vertically but inaccurate horizontally. Such horizontal deviations may be more significant then the 30 cm allowable error for depth data.

The airborne laser technique has a high potential in arctic and subarctic areas east of the Beaufort Sea and south of the Parry Channel during the open-water season. Extensive areas of uncharted and probably shoal waters are known to exist and the use of the equipment would generally not be limited by water clarity. Due to the variability of ice conditions in the arctic from year to year it would be advisable to have a number of field area options available each year and to undertake surveys on an oportunistic basis within an overall long-range plan.

The technique does not have a large-scale application in Canadian waters south of 60 °N. It could be used for individual surveys such as reported shoals or for restricted-area surveys, such as Sable Island. Limiting factors, in particular water clarity, would preclude the use of the survey method over extensive shoal areas (the lower Great Lakes: the southern Gulf of St. Lawrence: southwest Hudson Bay-James Bay) based on the limited data base and on a regional assessment. 7.6

Outside of Canada, the technique has a high potential use at a large-scale in areas where there exist extensive shallow-water areas with good water clarity. Examples might include the Bahama Banks or the Great Barrier Reef of Australia. Application of the laser technique to other environments is probably practical for most tropical and subtropical areas because (1) the water is clear due to infrequent and generally small plankton blooms, and (2) the algal cover is either limited or low-growing (e.g., less than 1 m tall). Major limitations would be in shallow, protected sedimentary areas, especially in bays and behind (shoreward of) coral reefs. Several seagrasses may be very dense, cover large areas, and grow up to several metres tall. Another possible limiting factor in some some estuarine environments could be the presence of floating vegetation such as water hyacinths. Much of the coastline, however, in tropical areas is coral reef rock, volcanic, or sandy, so that minimal biological interference with the laser operation would be encountered.

The feasibility analysis indicates that laser bathymetry is a 2 potential tool for approximately 120,000 km o f Canada's shelf waters. Apart from the depth parameter, the most limiting factor is water clarity. The existing data base is poor in most areas, but is generally adequate for this regional level of analysis. S3 3N3 1:13d38 013 8.0 REFERENCES

Atmospheric Environment Service, 1982a. Canadian Climate Normals, Volume III-Precipitation, 1951-1980. Environment Canada, 602 pp.

- Atmospheric Environment Service, 1982b. Canadian Climate Normals, Volume V-Wind, 1951-1980. Environment Canada, 203 pp.

Ayers, J.C., Anderson, D.V., Chandler, D.C., and Lauff, G.H., 1956. Currents and Water Masses of Lake Huron. University of Michigan, Great Lakes Research Division, Pub. No. 1, 101 pp.

Bailey, B.H. and Grainger, C.A., 1977. Lake Ontario Atlas: Climatology. New York Sea Grant Institute.

Beeton, A.M., 1962. Light penetration in the Great Lakes. Proc. of 5th Conference on Great Lakes Research, University of Michigan, Great Lakes Research Division, Pub. No. 9.

Bousfield, E.L., 1955. Some physical features of the Miramichi Estuary. J. Fish Res. Bd. Canada, 12(3): 342-361.

Bursa, A.S. 1961a. The Annual Oceanographic Cycle at Igloolik in the Canadian Arctic, II: the Phytoplankton. J. Fish. Res. Bd. Canada, 18(4):563-615.

Bursa, A.S., 1961b. Phytoplankton of the Colony Expeditions in Hudson Bay, 1953-1954. J. Fish. Res. Bd. Canada 18(1):51-83.

Canadian Hydrographic Service, 1974. Sailing Directions - British Columbia (South Portion) Vol. I. Ninth Edition, Dept. of Fisheries and Environment, Ottawa.

Canadian Hydrographic Service, 1979. Sailing Directions - Labrador and Hudson Bay. Fourth Edition, Dept. of Fisheries and Environment; Ottawa.

Clark, G.L., and Ewing, G.C., 1974. Remote sensing of ocean colour and index of biological and sedimentary activity. in (Block, P., ed.) Earth Survey Problems, Academic-Verlag, p. 107-120.

Duffus, H.J., 1979. Note on the Fraser River plume. Coastal Marine Science Laboratory, Royal Roads Military College, Victoria, Manuscript Report 79-5, 19 pp.

Energy, Mines and Resources, 1982. VFR Flight Supplement: Canada South of 60°N July 1982. Surveys and Mapping Branch, Canada.

Environment Canada, 1980. Historical Sediment Data Summary, Canadian Rivers to 1978. Inland Waters Directorate, Water Resources Branch, Water Survey of Canada, Ottawa, 121 pp. 8.2

Fenco Consultants Ltd., F.F. Slaney and Company Ltd, 1978. An Arctic Atlas: Background information for developing marine oil spill Countermeasures. Arctic Marine Oil Spill Program Report EPS-9-EC-78-1.

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