Urban Land Mapping from Remotely Sensed Data

Total Page:16

File Type:pdf, Size:1020Kb

Urban Land Mapping from Remotely Sensed Data M. J. JACKSON* Planning lntelligence Directorate (3) Department of the Environment London, England P. CARTER lmage Analysis Group, MPD Hanoell, Oxfordshire OX11 ORA, England T. I?. SMITH Planning Intelligence Directorate (3) Department of the Environment London, England W. G. GARDNER lmage Analysis Group, MPD Hanoell, Oxfordshire OX11 ORA, England Urban Land Mapping from Remotely Sensed Data Results suggest that the Landsat resolution is compatible with the requirement to map developed areas of 5 hectares or larger. INTRODUCTION use to which land is put in the United King- dom (UK) has not been available. Claims HE DEPARTMENT of the Environment have been made by some environmentalists T(DOE) is concerned with collecting in- that land is being destroyed by urban devel- formation on both the extent and distribution opment at an alarming rate. While the lim- ABSTRACT:All developed areas, offive hectares or above, in England and Wales were mapped using aerial photography flown in 1969. The Department of the Environment is now undertaking research and development with the Image Analysis Group, Harwell to enable the monitoring of urban growth from this base year by Landsat imagery. It is necessary, therefore, that the automated classification of urban growth from Landsat data be comparable to the aerial survey. To ensure this comparability it is necessary to quantify the differences in the classification systems and to emphasize the use of ground verification procedures. Present indications are that the Landsat resolution is compatible with the DOE'S basic requirement to map developed areas of ouer five hectares, though the capability to monitor change with the high level of accuracy required has not yet been established. The paper describes the ground-truth checking procedures and problems en- countered in monitoring urban growth. of developed land in England and Wales and ited statistics available do not confirm this the rate at which land is taken up by devel- view, the need for more comprehensive in- opment. In general, information about the formation does exist if land-use policies are to be monitored quantitatively. To meet this * Now with ETSU, Harwell, Oxfordshire 0x11 requirement a survey of developed areas ORA, England. from 1969 aerial photography was completed PHOTOGRAMMETRICENGINEERING AND REMOTE SENSING, Vol. 46, No. 8, August 1980, pp. 1041-1050. PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING, 1980 in 1978 and five categories of urban land use able for use with other data bases. This have been mapped at 1:50,000 scale. The stage constitutes a major undertaking and, maps cover the whole of England and Wales, because of the numerous manual opera- tions, is a common source of errors. and all "developed areas greater than five hectares have been digitized for computer The cost of the above three stages is high, processing and constitute the first national especially the acquisition of the data which data base of built-up areas. Further details may itself prove prohibitive. Also, while relating to this survey are given below and a there is a high level of redundancy in full description is given by Smith et al. 1:60,000 scale photography for national (1977). mapping restricted to urban land uses, this There is now a need to up-date regularly scale of imagery does not meet the needs of the initial data base. In order to test the county and local planning authorities where feasibility of using the Landsat satellite data, scales of 1:12,000 and greater are typical. the DOE and the Image Analysis Group of These factors and the increasing availability the Atomic Energy Research Establishment, of alternative forms of data collection mean Harwell, have developed a system for han- that it is important to consider other sources dling, displaying and classifying Landsat of land-use data which may be more appro- data (Carter and Jackson, 1976). The feasi- priate or cost efficient for the collection and bility of using the Landsat data can only be analysis of such broad national data. In par- checked by carrying out detailed "ground- ticular, the last few years have seen the in- truth" checks on selected test areas. troduction of side-looking radar imagery This paper describes the detailed check- (Henderson, 1977) for commercial and civil ing carried out to test the results obtained for purposes and spaceborne imaging systems the Landsat data and the consistency of clas- such as the multispectral scanners on-board sification of specific land-use parcels. De- the Landsat satellites. tailed results for one test area are presented. The use of Landsat imagery for informa- "Ground-truth," throughout the paper, tion at the national level overcomes many of will refer to land-use information collected the above problems related to the collection from aerial photographs, topographic maps, of data. Also, and most importantly, the cost and site visits and classified according to the of complete cover is very much less than for urban land-use class definitions used for the aerial photography. While the cloud prob- 1969 Developed Areas Survey. lem is not solved directly by the Landsat sat- ellites, the regular repetition of the orbits means that cloud-free coverage is likely at least on one or two occasions per year in the The data source for the survey of Devel- UK. The advantages of Landsat are now be- oped Land in 1969 was 1:60,000 scale pan- coming well known (see Anderson, 1977; chromatic aerial photography flown by the Gardner et al., 1977) and include the synop- Royal Air Force in 1969. There would be tic coverage and computer compatibility. three serious problems to be overcome, The potential of airborne and spaceborne however, if the DOE wished to commission radar fir urban mapping is less clear. The national aerial surveys on a regular commer- daylnight and cloud penetration capability of cial basis for the monitoring of land-use radar is an obvious advantage of this data change. source for areas experiencing the weather of These three problems are the UK. Complete cover of the UK by air- borne radar would be both quicker and The collection of data. Problems of air traffic control and particularly the cloudy cheaper than a photographic survey due to weather of the UK make comprehensive the far less stringent demands for "good fly- photographic cover on a regular basis both ing weather" and the wider swath-width of difficult and expensive. the obtained imagery. On the other hand, The handling and classification of data. neither manual nor automated interpretation Handling and organization of prints from has yet been demonstrated as being able to many sorties in itself creates problems. give sufficient land-use information to justify Classification of the photographs must be the cost of this data acquisition. undertaken by several interpreters, may Having assessed the feasibility of using take many months, and subjectivity in the classification procedure cannot be com- space imagery for urban monitoring at the pletely avoided. national level, the Department of the Envi- The computer processing of data. Fol- ronment is proceeding with research to es- lowing classification, the data must be tablish a rapid survey system based on digitized and processed into a format suit- automated techniques of interpreting and URBAN LAND MAPPING FROM REMOTELY SENSED DATA classifying images. It is expected that the The five categories are defined in detail following advantages will accrue for the suc- (DOE, 1978) with respect to the data sources cessful implementation of such a system: so as to obtain a high level of objectivity in the interpretation, which was undertaken by An increase in the amount and accuracy of land-use information for national and re- a commercial air-survey company. gional planning from regular and com- Using the above described "Developed prehensive surveys. Areas" maps, the outer boundary of the de- An increased ability to monitor trends in veloped area for a number of test sites has land use and to assess the spatial conse- been up-dated to the year of each Landsat quences of implementing planning classification with the aid of aerial photogra- policies. phy, maps, and site visits. The location of A reduction in time and manpower re- these sites is shown in Figure 1. The up- quired to produce national data. dating has not been applied individually to More objective information based on con- sistent criteria and related to a single time all the categories of use since the present base. research is concerned only with monitoring The application of the developed software change to the total developed area and not to a wider range of inventory problems with change of land use within those areas. than just urban land use. Urban open space (Category E) has, how- ever, been separately treated because the spectral return of such areas is similar to rural areas, and it has been therefore neces- The DOE survey of urban land use for sary to consider it as 'non-developed' for the 1969, referred to above, was used as the purposes of automated classification. While main source of ground-truth in assessing the it would be possible to add all 'non- accuracy of the Landsat classifications developed' areas wholly surrounded by new undertaken at Harwell. This survey mapped growth to the total developed area, new five urban land uses at the 1:50,000 scale in- peripheral urban open space cannot be so corporating all land-use parcels of five hec- easily incorporated into the total urban area. tares or more. The five land-use classes were Finally, all water surfaces of over five A. Residential. hectares have been separately mapped irre- B. Industrial and/or commercial. spective of their land-use category, which C. Education and/or community.
Recommended publications
  • Procedures for Gathering Ground Truth Information for a Supervised
    -- - 1 NASA m 1015 c.1 NASA Reference Publication 1015 .- .~ LOAN COPY: RETUf AFWL TECHNICAL L, KfRTLAND AFB, N Procedures for Gathering Ground Truth Information for a Supervised Approach to a Computer-Implemented Land Cover Classification of Landsat-Acquired Multispectral Scanner Data Armond T. Joyce JANUARY 1978 NASA TECH LIBRARY KAFB, NM lllll~~llllllllllllilRlllllll~l OOb32i’3 NASA Reference Publication 1015 Procedures for Gathering Ground Truth Information for a Supervised Approach to a Computer-Implemented Land Cover Classification of Landsat-Acquired Multispectral Scanner Data Armond T. Joyce Lyndon B. Johnson Space Center Houston, Texas National Aeronautics . and Space Administration Scientific and Technical Information Office 1978 CONTENTS Section Page SUMMARY................................ 1 INTRODUCTION ............................. 1 BACKGROUNDAND BASIC THEORY ...................... 2 FACTORS IN SELECTING TRAINING SAMPLE SITES .............. 3 Categorization of Land Surface Features ............... 3 Size and Shape of Training Sites .................. 7 Number and Distribution of Training Sites .............. 8 Homogeneity and Uniformity of Training Sites ............ 10 OPERATIONS BEFORE IMPLEMENTING FIELD PROCEDURES............ 13 Site Preselection By Use of Aerial Photography ........... 13 Site Referencing By Use of Prominent Surface Features ........ 14 Concentration of Sites ....................... 15 Acquisition of Aerial Photographs .................. 16 Use of Prints or Maps ........................ 17 Ground Truth
    [Show full text]
  • Spatial Accuracy Assessment in Natural Resources And
    This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. Attribute and Positional Accuracy Assessment of the Murray Darling Basin Project, Australia Fitzgerald, R.W.', Ritman, K.T. & Lewis, A. Abstract: The Murray Darling Basin comprises a land area of 1,058,000 km2 covering a substantial portion of SE Australia and encompassing Australia's largest river system. A basin wide woody vegetation dataset has been assembled from LANDSAT TM imagery supplemented with aerial photography at a nominal scale of 1: 100,000. The attribute accuracy assessment method is based on a multi-stage systematic sample design. A rectangular grid is placed over the entire Murray Darling Basin dataset and at each primary sample point, a secondary grid is created formed from a square contiguous set of aerial photos. A half tone, grey scale transparency covering approximately 10km2 is generated from satellite digital imagery (LANDSAT TM) for each primary grid point at a contact scale matching the available air photos. Overprinted on this transparency are the secondary grid points as patch size sampling frames. The air photos are then visually co-registered underneath the transparency with Landcover features from the LANDSAT TM image. Attribute data (presence or absence of woody vegetation) is collected directly from the air photos for each secondary grid point at 4 different patch sizes. Positional accuracy is assessed by recording 40 or more ground control points from the 1: 100,000 map sheet containing the primary grid point. These Eastings and Northings are compared to their position in the LANDSAT TM image.
    [Show full text]
  • ISPRS Journal of Photogrammetry and Remote Sensing 142 (2018) 292–300
    ISPRS Journal of Photogrammetry and Remote Sensing 142 (2018) 292–300 Contents lists available at ScienceDirect ISPRS Journal of Photogrammetry and Remote Sensing journal homepage: www.elsevier.com/locate/isprsjprs The effects of imperfect reference data on remote sensing-assisted estimators T of land cover class proportions ⁎ Ronald E. McRobertsa, , Stephen V. Stehmanb, Greg C. Liknesa, Erik Næssetc, Christophe Sannierd, Brian F. Waltersa a Northern Research Station, U.S. Forest Service, Saint Paul, MN, USA b Forest and Natural Resources Management, State University of New York, Syracuse, NY, USA c Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway d Systèmes d'Information à Référence Spatiale (SIRS), Villeneuve d'Ascq, France ARTICLE INFO ABSTRACT Keywords: The gain-loss approach for greenhouse gas inventories requires estimates of areas of human activity and esti- Intepreter error mates of emissions per unit area for each activity. Stratified sampling and estimation have emerged as a popular Bias and useful statistical approach for estimation of activity areas. With this approach, a map depicting classes of Precision activity is used to stratify the area of interest. For each map class used as a stratum, map units are randomly Greenhouse gas inventory selected and assessed with respect to an attribute such as forest/non-forest or forest land cover change. Ground Gain-loss method observations are generally accepted as the most accurate source of information for these assessments but may be cost-prohibitive to acquire for remote and inaccessible forest regions. In lieu of ground observations, visual interpretations of remotely sensed data such as aerial imagery or satellite imagery are often used with the caveat that the interpretations must be of greater quality than the map data.
    [Show full text]
  • Ground Truth Studies Teacher Handbook
    DRAFT VER / 1.1 N GLO E B P A S L A C H E A T N U G IT E INST Ground Truth Studies Teacher Handbook © ASPEN GLOBAL CHANGE INSTITUTE 1995 GROUND TRUTH STUDIES i Printing History First U.S. Edition First Printing June 1992 Second Printing July 1993 Canadian Edition First Printing June 1994 Second U.S. Edition Third Printing June 1995 Forth Printing December 2000 Subsequent Printings by Print on Demand © 1992, 1995, 2003 Aspen Global Change Institute All rights reserved. For reproduction in whole or part, obtain permission from the— Aspen Global Change Institute 100 East Francis Street Aspen, Colorado 81611 tel 970 925 7376 fax 970 925 7097 email [email protected] homepage http://www.agci.org Printed on 100% recycled paper using soy-based inks. Contributing Authors Jesse Boyce; Susan Hassol; John Katzenberger; Martha Kirpes; Anthony Leiserowitz; William Stapp. Design and Production Kelly Alford/Words Colors Pictures. Acknowledgments The GTS Teacher Handbook is a cross-disciplinary synthesis of the talents, skills and wisdom of an international group of scientists and educators. A heartfelt thank-you to them all. The Curriculum Development Team Mr. Walter Bogan, AAAS; Dr. Cheryl Charles, Project WILD; Mr. Gregory Cox, University of Alabama/Huntsville; Dr. William Kuhn, University of Michigan; Dr. James Lawless, NASA; Dr. Milton McClaren, Simon Fraser University; Dr. William Stapp, University of Michigan; and Mr. Thomas Wagner, ERIM. Pilot Teachers Ms. Elaine Bonds, Aspen Elementary School, Aspen, CO; Ms. Vicki Clark, Mathematics & Science Center, Richmond, VA; Ms. Cheryl Cleeves, Clifford Elementary School, Redwood City, CA; Ms.
    [Show full text]
  • Air Photointerpretation and Satellite Imagery Analysis Techniques for Mapping Cattail Coverage in a Northern Everglades Impoundment
    Air Photointerpretation and Satellite Imagery Analysis Techniques for Mapping Cattail Coverage in a Northern Everglades Impoundment Ken Rutchey and Les Vilchek Abstract 20 wetland categories using ERDAS software. The thematic ac- Color-infrared aerial photography taken in 1991 and 1995, curacy of this 20-wetland-class image, determined by analyz- and SPOT satellite imagery taken in 1991, were utilized to ing 241 stratified random ground reference points located create cattail coverage maps for Water Conservation Area 2A using global positioning system (GPS)instruments, was 70.9 (WCAZA), an impounded portion of the remnant Everglades. percent. A final consolidation of these 20 classes to form a Cattail stands were delineated and classified using conven- 12-class image gave an overall accuracy of 80.9 percent tional air photointerpretation and digital image processing (Rutchey and Vilchek, 1994). techniques, respectively. Four interacting confounding factors The methods used in the Rutchey and Vilchek (1994) (i.e., water depth/color, impacts from fire, periphyton species study were chosen because (1)there was a need to assess the composition, and growth morphology within a single species) utility of satellite imagery for mapping Everglades wetlands; are implicated as possible elements that complicated vegeta- (2) the equipment (both software and hardware) were avail- tion classification. Photointerpretation techniques showed an able; (3) it was more economical than using photointerpre- increasing trend in cattail encroachment from 421.6 hectares tation; and (4) the results could be digitally reproduced. of monotypic cattail in 1991 to 1646.3 hectares in 1995. A Overall, the accuracy results were modest for this type of 1991 SPOT classified image appears to have overestimated digital classification.
    [Show full text]
  • Engineering Geology Field Manual
    Chapter 15 REMOTE SENSING TECHNIQUES Introduction This chapter briefly summarizes the capabilities, limitations, and requirements of typical remote sensing techniques. Depending on the nature of the data and the objective of the study, geologic interpretation of remotely sensed data may be simple or complicated. Remote sensing is a tool that makes some tasks easier, makes possible some tasks that would otherwise be impossible, but is inappropriate for some tasks. Depending on the individual situation, remote sensing may be extremely valuable. Some remote sensing interpretations can stand on their own with confidence, but for most, establishing ground truth is essential. Imaging Systems There are three main types of imaging systems, two of which are widely used in terrestrial applications: Photographic.—Cameras and film are used. Photography provides the best spatial resolution but less flexibility in spectral data collection and image enhancement. Spatial resolution is dependent on alti- tude, focal length of lenses, and the types of film used. Spectral resolution is limited to visible and near infrared wavelengths. Electronic Spectral Sensors.— Detectors are used, usually scanners, that may have less spatial resolution than photographs but can gather spectral data over wide spectral ranges that enable a wide variety of imaging processing, mineral, and geologic identification. These remote sensing systems include satellites, such as Landsat, airborne sensors carried on aircraft, and FIELD MANUAL spectrometers carried on the ground. This type of remote sensing has several categories, including multi- spectral, hyperspectral, and imaging spectroscopy. Vidicon. – A television-type system. Vidicon systems generally are inferior to other types both spatially and spectrally. They are used mostly on space probes because of operational constraints.
    [Show full text]