6Th Biennial Report

Total Page:16

File Type:pdf, Size:1020Kb

6Th Biennial Report 6th Biennial Report Submitted to National Marine Fisheries Service and United States Fish and Wildlife Service By Green Diamond Resource Company in fulfillment of requirements pursuant to NMFS Permit No. 1613 and USFWS Permit No. TE156839-0 March 15, 2019 TABLE OF CONTENTS PAGE I. Introduction ................................................................................................ 1 II. AHCP Compliance ..................................................................................... 2 A. AHCP Implementation Plan ........................................................................ 2 B. Field Trials with Mechanized Equipment .................................................... 2 C. Commercial Thinning ................................................................................. 5 D. AHCP Minor Modifications ......................................................................... 6 1. Minor Modification to AHCP Sections 6.2.3.5.9, 6.2.1.2.6 and 6.2.1.4.5 (Road Construction in RMZs) ............................................................... 7 2. Minor Modification to AHCP Sections 6.2.4.5.2 and 6.2.4.7 (Limited Use of Existing Skid Trails on Slopes Greater than 45 percent) ......... 10 3. Minor Modification to AHCP Sections 6.2.3.9.3 and 6.2.3.9.4 (Modifications to the Routine Road Maintenance and Inspection Plan: Schedule for RMAs and Mainline Roads) ........................................... 13 E. Forms for RPFs and Conservation Planning Staff to Document Pre- Harvest Conservation Measures for Each THP and Compliance with Those Measures Post-Harvest ................................................................. 16 F. Summary of THP Conservation Measures and Compliance with Those Measures While Operating Under the AHCP ........................................... 16 1. Notice of Filings .................................................................................. 16 2. Summary of Conservation Measures for Approved AHCP THPs ....... 17 3. Summary of Conservation Measures for Completed AHCP THPs ..... 17 III. Land Transactions and Plan Area Adjustments ....................................... 27 A. Notice of Transactions ............................................................................. 27 B. Land Transactions .................................................................................... 28 1. Plan Area Additions ............................................................................ 28 2. Plan Area Deletions ............................................................................ 28 3. Limitations on Plan Area Transactions ............................................... 28 4. Minor Modifications to the Plan Area .................................................. 29 C. Summary of Land Transactions and Plan Area Adjustments ................... 29 IV. AHCP Training Programs ......................................................................... 31 A. 2017 Training Programs ........................................................................... 31 B. 2018 Training Programs ........................................................................... 32 V. Road Management Measures .................................................................. 32 ii A. Programmatic Road Permits .................................................................... 32 B. Road Assessment Process ...................................................................... 34 C. Road Implementation Plan ....................................................................... 35 D. Road Maintenance and Inspection Plan ................................................... 44 VI. Geology .................................................................................................... 46 A. CMZ/Floodplain Delineation ..................................................................... 46 B. SSS Delineation Plan (AHCP Section 6.2.5.3.2) ...................................... 46 C. SSS Assessment (AHCP Section 6.2.5.3.3) ............................................ 47 1. Current Status of the SSS Assessment .............................................. 47 D. Mass Wasting Assessment (AHCP Section 6.2.5.3.4) ............................. 48 1. Purpose and Scope of the Assessment .............................................. 48 2. Current Status ..................................................................................... 48 VII. Budget ...................................................................................................... 49 VIII. Effectiveness Monitoring .......................................................................... 51 A. Rapid Response Monitoring ..................................................................... 52 1. Property-wide Water Temperature Monitoring .................................... 52 2. Tailed Frog Monitoring ........................................................................ 57 3. Southern Torrent Salamander Monitoring ........................................... 61 4. Road Treatment Implementation and Effectiveness Monitoring .......... 65 B. Response Monitoring ............................................................................... 66 1. Class I Channel Monitoring ................................................................. 67 2. Class III Sediment Monitoring ............................................................. 72 C. Long-Term Trend Monitoring .................................................................... 73 1. Long-Term Habitat Assessment ......................................................... 74 2. LWD Monitoring .................................................................................. 81 3. Summer Juvenile Population Estimates.............................................. 90 4. Outmigrant Trapping ........................................................................... 98 5. Turbidity Threshold Sampling ........................................................... 108 D. Experimental Watersheds ...................................................................... 109 1. Riparian Canopy Modification Experiment ........................................ 111 2. Pilot Project: SF Ah Pah Creek ........................................................ 113 3. Tectah Creek Riparian Canopy Experiment ...................................... 125 E. Protocol Updates .................................................................................... 128 iii IX. Adaptive Management Account ............................................................. 128 X. Changed Circumstances ........................................................................ 129 XI. Literature Cited ....................................................................................... 131 XII. Glossary ................................................................................................. 136 A. Abbreviations ......................................................................................... 136 B. Definitions .............................................................................................. 137 XIII. Appendices ............................................................................................ 151 A. Post-Harvest Forms of Completed THPs ............................................... A-1 B. Steep Streamside Slope (SSS) Assessment Field Data Sheet .............. B-1 C. Summary Table of Road Treatment Implementation and Effectiveness Monitoring Results from 2017 and 2018 ................................................ C-1 LIST OF TABLES PAGE Table 1. Summary of areas (acres) for each harvest type for the 98 approved THPs. .................................................................................................................. 19 Table 2. Summary of areas (acres) for each harvest type for 62 completed THPs. .................................................................................................................. 19 Table 3. Summary of the riparian features and the average length of each feature in the 62 completed THPs with prescribed AHCP protection measures, during the reporting period. ................................................................................. 20 Table 4. Summary of proposed road work and the average length of proposed road work in the 61 completed THPs with road work, during the reporting period. ............................................................................................................................ 20 Table 5. Summary of geomorphic features observed within THPs during the reporting period. .................................................................................................. 21 Table 6. The distribution of geomorphic features by watercourse type. ............. 22 Table 7. Summary of SSS prescriptions associated by watercourse type. ........ 22 Table 8. Summary of AHCP exceptions. ............................................................ 23 Table 9. Summary of timber harvest plans with alternative geologic prescriptions. ...................................................................................................... 23 Table 10. Summary of harvest-related alternative geologic prescriptions and area of alternative geologic prescriptions applied per THP. ................................ 24 Table 11. Summary of hazard abatement activities. .......................................... 25 Table 12. Summary of land transactions and minor modifications that occurred between January 1, 2017 and December 31, 2018. ..........................................
Recommended publications
  • Surficial Geologic Map of the Ahsahka Quadrangle, Clearwater County
    IDAHO GEOLOGICAL SURVEY DIGITAL WEB MAP 7 MOSCOW-BOISE-POCATELLO OTHBERG, WEISZ, AND BRECKENRIDGE SURFICIAL GEOLOGIC MAP OF THE AHSAHKA QUADRANGLE, Disclaimer: This Digital Web Map is an informal report and may be revised and formally published at a later time. Its content and format CLEARWATER COUNTY, IDAHO may not conform to agency standards. Kurt L. Othberg, Daniel W. Weisz, and Roy M. Breckenridge 2002 embayments that now form the eastern edge of the Columbia River Plateau where the relatively flat region meets the mountains. Sediments of the Latah Qls Formation are interbedded with the basalt flows, and landslide deposits QTcr occur where major sedimentary interbeds are exposed along the valley sides. Qcg Pleistocene loess forms a thin discontinuous mantle on deeply weathered surfaces of the basalt plateau and mountain foothills. In the late Pleistocene, multiple Lake Missoula Floods inundated the Clearwater River valley, locally Qcb Qcb depositing silt, sand, and ice-rafted pebbles and cobbles in the lower elevations of the canyon. QTcr QTlsr The bedrock geology of this area is mapped by Lewis and others (2001) and shows details of the basement rocks and the Miocene basalt flows and Qcg sediments. The bedrock map’s cross sections are especially useful for QTlbr Qls interpreting subsurface conditions suitable for siting water wells and assessing Qls the extent and limits of ground water. Qac Qls QTlsr SURFICIAL DEPOSITS QTlbr QTlbr m Made ground (Holocene)—Large-scale artificial fills composed of excavated, transported, and emplaced construction materials of highly varying composition, but typically derived from local sources. Qam QTlsr Alluvium of mainstreams (Holocene)—Channel and flood-plain deposits of the Clearwater River that are actively being formed on a seasonal or annual Qls Qls basis.
    [Show full text]
  • Mass Movement in Two Selected Areas of Western Washington County, Vania
    Mass Movement in Two Selected Areas of Western Washington County, vania GEOLOGICAL SURVEY PROFESSIONAL PAPER 1170-B MASS MOVEMENT IN TWO SELECTED AREAS OF WESTERN WASHINGTON COUNTY, PENNSYLVANIA Recent earthflows along concave-convex east- to north-facing slopes west of Prosperity, Pa. Mass Movement in Two Selected Areas of Western Washington County, Pennsylvania By JOHN S. POMEROY SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 1170-B Landsliding and its relation to geology and an analysis of various interpretive elements in a region of the Allegheny Plateau subject to landslides UNITED STATES GOVERNMENT PRINTING OFFICE, W AS H INGTON : 1 982 UNITED STATES DEPARTMENT OF THE INTERIOR JAMES G. WATT, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director Library of Congress Cataloging in Publication Data Pomeroy, John S 1929- Mass movement in two selected areas of western Washington County, Pennsylvania. (Shorter contributions to general geology) (Geological Survey professional paper ; 1170-B) Bibliography: p. Supt. of Docs, no.: I 19.16:1170-B 1. Mass-wasting-Pennsylvania-Washington Co. I. Title. II. Series: United States. Geological Survey. Shorter contributions to general geology. III. Series: United States. Geological Survey. Professional paper ; 1170-B. QE599.U5P65 551.3 80-607835 AACR1 For sale by the Distribution Branch, U.S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 CONTENTS Page Page Abstract ______________________________ Bl Short Creek area __________________________ BIO Introduction
    [Show full text]
  • Surficial Geologic Map of the Dent Quadrangle, Clearwater County, Idaho
    IDAHO GEOLOGICAL SURVEY DIGITAL WEB MAP 6 MOSCOW-BOISE-POCATELLO OTHBERG, WEISZ, AND BRECKENRIDGE Disclaimer: This Digital Web Map is an informal report and may be revised and formally published at a later time. Its content and format may not conform to agency standards. SURFICIAL GEOLOGIC MAP OF THE DENT QUADRANGLE, CLEARWATER COUNTY, IDAHO Kurt L. Othberg, Daniel W. Weisz, and Roy M. Breckenridge 2002 DESCRIPTION OF MAP UNITS Qcg Qcg Qls INTRODUCTION Qls Qcb Qcb The surficial geologic map of the Dent quadrangle identifies earth materials Qcg on the surface and in the shallow subsurface. It is intended for those interested in the area's natural resources, urban and rural growth, and private and DWORSHAK public land development. The information relates to assessing diverse Qcb conditions and activities, such as slope stability, construction design, sewage drainage, solid waste disposal, and ground-water use and recharge. Qls The geology was intensively investigated during a one-year period. Natural ELE VAT and artificial exposures of the geology were examined and selectively 16 IO RESERVOIRQcg 00 N collected. In addition to field investigations, aerial photographs were studied Qls to aid in identifying boundaries between map units through photogeologic mapping of landforms. In most areas map-unit boundaries (contacts) are approximate and were drawn by outlining well-defined landforms. It is rare that contacts between two units can be seen in the field without excavation Qls Qcg operations which are beyond the purpose and scope of this map. The contacts are inferred where landforms are poorly defined and where lithologic Qcg characteristics grade from one map unit into another.
    [Show full text]
  • Colluvial Deposit
    Encyclopedia of Planetary Landforms DOI 10.1007/978-1-4614-9213-9_55-1 # Springer Science+Business Media New York 2014 Colluvial Deposit Susan W. S. Millar* Department of Geography, Syracuse University, Syracuse, NY, USA Synonyms Colluvial depositional system; Colluvial mantle; Colluvial soil; Colluvium; Debris slope; Hillslope (or hillside) deposits; Scree (UK); Slope mantle; Slope-waste deposits; Talus (US) Definition A sedimentary deposit composed of surface mantle that has accumulated toward the base of a slope as a result of transport by gravity and non-channelized flow. Description The International Geomorphological Association recognizes colluvium as a hillslope deposit resulting from two general nonexclusive processes (Goudie 2004). Rainwash, sheetwash, or creep can generate sediment accumulations at the base of gentle slopes; or non-channelized flow can initiate sheet erosion and toe-slope sediment accumulation. The term “colluvium” is frequently applied broadly to include mass wasting deposits in a variety of topographic and climatic settings. For example, Blikra and Nemec (1998) describe colluvium as any “clastic slope-waste material, typically coarse grained and immature, deposited in the lower part and foot zone of a mountain slope or other topographic escarpment, and brought there chiefly by sediment-gravity processes.” Lang and Honscheidt (1999) describe colluvium as “slope wash and tillage sediments, resulting from soil erosion....” The composition of a colluvial deposit can therefore be coarse-grained, eroded bedrock, with an open-work structure and several meters thick (Blikra and Nemec 1998), to fine-grained soil, ranging from a few millimeters to meters in thickness (e.g., Lang and Hönscheidt 1999). Some deposits may exhibit distinct macro- and micro-fabric development, bedding structures, and evi- dence of distinct periods of accumulation (e.g., Bertran et al.
    [Show full text]
  • This File Was Created by Scanning the Printed Publication
    This file was created by scanning the printed publication. Text errors identified by the software have been corrected; however, some errors may remain. Editors SHARON E. CLARKE is a geographer and GIS analyst, Department of Forest Science, Oregon State University, Corvallis, OR 97331; and SANDRA A. BRYCE is a biogeographer, Dynamac Corporation, Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, Corvallis, OR 97333. This document is a product of cooperative research between the U.S. Department of Agriculture, Forest Service; the Forest Science De- partment, Oregon State University; and the U.S. Environmental Protection Agency. Cover Artwork Cover artwork was designed and produced by John Ivie. Abstract Clarke, Sharon E.; Bryce, Sandra A., eds. 1997. Hierarchical subdivisions of the Columbia Plateau and Blue Mountains ecoregions, Oregon and Washington. Gen. Tech. Rep. PNW-GTR-395. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 114 p. This document presents two spatial scales of a hierarchical, ecoregional framework and provides a connection to both larger and smaller scale ecological classifications. The two spatial scales are subregions (1:250,000) and landscape-level ecoregions (1:100,000), or Level IV and Level V ecoregions. Level IV ecoregions were developed by the Environmental Protection Agency because the resolution of national-scale ecoregions provided insufficient detail to meet the needs of state agencies for estab- lishing biocriteria, reference sites, and attainability goals for water-quality regulation. For this project, two ecoregions—the Columbia Plateau and the Blue Mountains— were subdivided into more detailed Level IV ecoregions.
    [Show full text]
  • NREM 301 Day 9
    NREM 301 Day 9 • Quiz on Thursday! • Continue discussing sequences (focusing on central IA) • Discuss Soil Taxonomy and major soil orders • Lab Today – “Identifying Soil Bio- and Toposequences” – Individual Assignment – due Thurs. Oct. 2. Soil Definition for Soil • A Natural Body • Unconsolidated Mixture • Mineral & Organic Matter • Living & Dead • Developing in Place Over Time Dirt So - soils vary dramatically spatially & temporally Because of: Soil = f(Cli, p, r, o, t) Cli = climate P = parent material R = relief O = organisms T = time High elevation – cold Soil = f(Cli, p, r, o, t) Cli = Climate What Soil Differences Would 5,000 ft – warm, humid You Expect? Why? Granite Glacial Till Soil = f(Cli, p, r, o, t) P = Parent Material What Soil Differences Would You Expect? Why? Soil Parent Materials – the raw mineral material soils are developing in. Rocks and Minerals Deposited in oceans -marine sediment Deposited in lakes ----lacustrine sediment Deposited in streams -alluvium – floodplain, delta terrace, fan ice Deposited by ice ----glacial till --- moraines transport Deposited by water --outwash – alluvium, marine lacustrine Deposited by wind - eolian --- loess, eolian sand, Residual sediment volcanic ash parent material (bedrock weathered Deposited by gravity –colluvium – creep, landslides in place) types of examples of deposits landforms or deposits Modified from Brady and Weil. 2002. The nature and properties of soils. 13th edition. Prentice Hall. N or E facing S or W facing Soil = f(Cli, p, r, o, t) r = Relief/Topography What Soil
    [Show full text]
  • Mass Movements General Anatomy
    CE/SC 10110-20110: Planet Earth Mass Movements Earth Portrait of a Planet Fifth Edition Chapter 16 Mass movement (or mass wasting) is the downslope motion of rock, regolith (soil, sediment, and debris), snow, and ice. General Anatomy Discrete slump blocks Head scarp Bulging toe Road for scale Disaster in the Andes: Yungay, Peru, 1970 Fractures rock, loosens soil particles. Seismic energy overstresses the system. Yungay, Peru, in the Santa River Valley beneath the heavily glaciated Nevado Huascarán (21,860 feet). May, 1970, earthquake occurred offshore ~100 km away - triggered many small rock falls. An 800-meter-wide block of ice was dislodged and avalanched downhill, scooping out small lakes and breaking off large masses of rock debris. Disaster in the Andes: Yungay, Peru, 1970 More than 50 million cubic meters of muddy debris traveled 3.7 km (12,000 feet) vertically and 14.5 km (9 miles) horizontally in less than 4 minutes! Main mass of material traveled down a steep valley, blocking the Santa River and burying ~18,000 people in Ranrachirca. A small part shot up the valley wall, was momentarily airborne before burying the village of Yungay. Estimated death toll = 17,000. Disaster in the Andes: Yungay, Peru, 1970 Before After Whats Left of Yungay. Common Mass Movements Rockfalls and Slides Slow Fast Debris Flows Slumping Lahars and Mudflows Solifluction and Creep These different kinds of mass movements are arranged from slowest (left) to fastest (right). Types of Mass Movement Different types of mass movement based on 4 factors: 1) Type of material involved (rock, regolith, snow, ice); 2) Velocity of the movement (slow, intermediate, fast); 3) Character of the movement (chaotic cloud, slurry, coherent mass; 4) Environment (subaerial, submarine).
    [Show full text]
  • Weathering, Erosion, and Mass-Wasting Processes
    Weathering, Erosion, and Mass-Wasting Processes Designed to meet South Carolina Department of Education 2005 Science Academic Standards 1 Table of Contents (1 of 2) Definitions: Weathering, Erosion, and Mass-Wasting (slide 4) (Standards: 3-3.8 ; 5-3.1) Types of Weathering (slide 5) (Standards: 3-3.8 ; 5-3.1) Mechanical Weathering (slide 6) (Standards: 3-3.8 ; 5-3.1) Exfoliation (slide 7) (Standards: 3-3.8 ; 5-3.1) Frost Wedging (slide 8) (Standards: 3-3.8 ; 5-3.1) Temperature Change (slide 9) (Standards: 3-3.8 ; 5-3.1) Salt Wedging (slide 10) (Standards: 3-3.8 ; 5-3.1) Abrasion (slide 11) (Standards: 3-3.8 ; 5-3.1) Chemical Weathering (slide 12) (Standards: 3-3.8 ; 5-3.1) Carbonation (slide 13) (Standards: 3-3.8 ; 5-3.1) Hydrolysis (slide 14) (Standards: 3-3.8 ; 5-3.1) Hydration (slide 15) (Standards: 3-3.8 ; 5-3.1) Oxidation (slide 16) (Standards: 3-3.8 ; 5-3.1) Solution (slide 17) (Standards: 3-3.8 ; 5-3.1) Biological Weathering (slide 18) (Standards: 3-3.8 ; 5-3.1) Lichen, Algae, and Decaying Plants (slide 19) (Standards: 3-3.8 ; 5-3.1) Plant Roots (slide 20) (Standards: 3-3.8 ; 5-3.1) Organism Activity: Burrowing, Tunneling, and Acid Secreting Organisms (slide 21) (Standards: 3-3.8 ; 5-3.1) Differential Weathering (slide 22) (Standards: 3-3.8 ; 5-3.1) 2 Table of Contents, cont. (2 of 2) Types of Erosion (slide 23) (Standards: 3-3.8 ; 5-3.1) Fluvial (slide 24) (Standards: 3-3.8 ; 5-3.1) Aeolian (slide 25) (Standards: 3-3.8 ; 5-3.1) Ice: Glacial and Periglacial (slide 26) (Standards: 3-3.8 ; 5-3.1) Gravity (slide
    [Show full text]
  • Characteristics of the Ecoregions of Montana (Continued) Second Edition
    DRAFT 2 Summary Table: Characteristics of the Ecoregions of Montana (continued) Second Edition 41. CANADIAN ROCKIES 43. NORTHWESTERN GREAT PLAINS Level IV Ecoregion Physiography Geology Soil Climate Potential Natural Vegetation* Land Cover and Land Use Level IV Ecoregion Physiography Geology Soil Climate Potential Natural Vegetation* Land Cover and Land Use Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Ross, R.L., and Hunter, H.E., 1976 (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 miles) (feet) Regimes (inches) (days) July min/max (oF) miles) (feet) Regimes (inches) (days) July min/max (oF) or Seasonality 41a. Northern Front 592 Glaciated. Forested mountains east of the 4500-7700/ Quaternary glacial drift, alluvium, and Alfi sols (Cryoboralfs), Loberg, Garlet, Evaro, Cryic/ 20-90 30-70 Long cold Subalpine fi r and Douglas-fi r Recreation is the major land use within 43a. Missouri Plateau 3425 Unglaciated (or not signifi cantly modifi ed by 2000-3550/ Quaternary terrace deposits. Primarily, Mollisols (Argiborolls, Chama, Morton, Bainville, Frigid/ 11-16 100-130 0/26; Wheatgrass–needlegrass. Mosaic of rangeland and farmland; Continental Divide are in the rainshadow of 400-2000 colluvium. Cretaceous undifferentiated Inceptisols (Cryochrepts), Mikesell, Whitore, Mord, Ustic, winters, moist forests. Glacier National Park; elsewhere, glaciation). Rolling hills and gravel-covered 50-500 Tongue River and Slope members of the Calciborolls, Flasher, Farnuf, Turner, Ustic 54/90 spring wheat, hay, barley, and oats are the Rocky Mountains and are underlain mostly sedimentary rock; also thrust-faulted, Mollisols (Cryoborolls) Helmville, Cowood, Cheadle, Udic springs logging, recreation, rural residential benches are extensive.
    [Show full text]
  • Experimental Forests and Ranges of the USDA Forest Service
    United States Department of Experimental Forests and Ranges Agriculture Forest Service of the USDA Forest Service Northeastern Research Station General Technical Report NE-321 Revised Abstract The USDA Forest Service has an outstanding scientific resource in the 79 Experimental Forests and Ranges that exist across the United States and its territories. These valuable scientific resources incorporate a broad range of climates, forest types, research emphases, and history. This publication describes each of the research sites within the Experimental Forests and Ranges network, providing information about history, climate, vegetation, soils, long-term data bases, research history and research products, as well as identifying collaborative opportunities, and providing contact information. The Compilers MARY BETH ADAMS, soil scientist, LINDA H. LOUGHRY, secretary, LINDA L. PLAUGHER, support services supervisor, USDA Forest Service, Northeastern Research Station, Timber and Watershed Laboratory, Parsons, West Virginia. Manuscript received for publication 17 November 2003 Published by: For additional copies: USDA FOREST SERVICE USDA Forest Service 11 CAMPUS BLVD SUITE 200 Publications Distribution NEWTOWN SQUARE PA 19073-3294 359 Main Road September 2004 Delaware, OH 43015-8640 Revised March 2008 Fax: (740)368-0152 Revised publication available in CD-ROM only Visit our homepage at: http://www.nrs.fs.fed.us Experimental Forests and Ranges of the USDA Forest Service Compiled by: Mary Beth Adams Linda Loughry Linda Plaugher Contents Introduction
    [Show full text]
  • The Influence of Debris Flows on Channels and Valley Floors in the Oregon Coast Range, U.S.A
    EARTH SURFACE PROCESSES AND LANDFORMS, VOL. 15, 457-466 (1990) THE INFLUENCE OF DEBRIS FLOWS ON CHANNELS AND VALLEY FLOORS IN THE OREGON COAST RANGE, U.S.A. LEE BENDA Department of Geological Sciences (AJ-20 ), University of Washington, Seattle, Washington 98195, U.S.A. Received 24 August 1989 Revised 2 January 1990 ABSTRACT Debris flows are one of the most important processes which influence the morphology of channels and valley floors in the Oregon Coast Range. Debris flows that initiate in bedrock hollows at heads of first-order basins erode the long- accumulated sediment and organic debris from the floors of headwater, first- and second-order channels. This material is deposited on valley floors in the form of fans, levees, and terraces. In channels, deposits of debris flows control the distribution of boulders. The stochastic nature of sediment supply to alluvial channels by debris flows promotes cycling between channel aggradation which results in a gravel-bed morphology, and channel degradation which results in a mixed bedrock- and boulder-bed morphology. Temporal and spatial variability of channel-bed morphology is expected in other landscapes where debris flows are an important process. KEY WORDS Debris flows Mountain channels Channel aggradation INTRODUCTION Debris flows in the west coast of North America form as landslide debris liquifies and moves through steep, confined, headwater channels for distances up to several kilometres at speeds up to 10-15 m s t . The flows are extremely erosive and incorporate additional sediment from channels, as well as or ganic debris and water, and they deposit this material in lower-gradient channels and valley bottoms.
    [Show full text]
  • Geological-Geotechnical Properties of a Colluvial Soil in a Natural Slope Cut by a Pipeline
    ISSN: 1980-900X (online) GEOLOGICAL-GEOTECHNICAL PROPERTIES OF A COLLUVIAL SOIL IN A NATURAL SLOPE CUT BY A PIPELINE PROPRIEDADES GEOLÓGICO-GEOTÉCNICAS DE UM SOLO COLUVIONAR EM ENCOSTA NATURAL CORTADA POR UMA DUTOVIA Talita Gantus OLIVEIRA1, Alberto Pio FIORI1, Rodrigo Moraes da SILVEIRA2 1Universidade Federal do Paraná. Rua XV de Novembro, 1299 - Centro, Curitiba – PR. E-mails: [email protected]; [email protected] 2Lactec – Instituto de Tecnologia para o Desenvolvimento. Avenida Comendador Franco, 1341. Jardim Botânico, Curitiba - PR E-mail: [email protected] Introduction Geological Aspects and Location of Study Area Methods Field Investigation Remote Sensing Soil Classification Determination of Geotechnical Properties Geomechanical Parameters Hydraulic Parameters Results and Discussion Conclusions Acknowledgments References ABSTRACT - The Serra do Mar, in the state of Paraná, Brazil, is marked by a relief with unstable areas, which is eventually subjected to mass movements along their slopes, primarily caused by the large amounts of rainfall that occur in such area. Within this scenario fits a pipeline conduit for the transportation of fuels, often bordering slopes in a situation of precarious balance. It is widely known that lithological, structural and geomorphic features play a major role in the slopes stability. Thus, it is important to understand the dynamics of these movements in order to preserve the physical integrity of the duct. Areas where the slope represents critical points of instability were selected for the study along the pipeline section. The main objective of this work is to investigate the geological and geotechnical features of the area cut by the pipeline in order to assess possible mass movements.
    [Show full text]