UID:
kobvindex_GFZ20190521150909
Format:
iv, 26 Seiten
,
Illustrationen
Series Statement:
CRREL Report 83-29
Content:
A literature review indicated that the effects or permafrost on streambank erodibility and stability are not yet understood because systematic and quantitative measurements are seriously lacking. Consequently, general controversy exists as to whether perennially frozen ground inhibits lateral erosion and bankline recession, or whether it increases bank recession rates. Perennially frozen streambanks erode because of modification of the bank's thermal regime by exposure to air and water, and because of various erosional processes. Factors that determine rates and locations of erosion include physical, thermal and structural properties of bank sediments, stream hydraulics and climate. Thermal and physical modification of streambanks may also induce accelerated erosion within permafrost terrain removed from the immediate river environment. Bankline or bluffline recession rates are highly variable, ranging from less than 1 m/year to over 30 m/year and, exceptionally, to over 60 m/year. Long-term observations of the physical and thermal erosion processes and systematic ground surveys and measurements of bankline-bluffline recession rates are needed.
Note:
CONTENTS
Abstract
Preface
Introduction
Stream bank erosional processes
Permafrost and related factors
Permafrost and erosion
General
Erosional processes
Bank zone processes
Bluff zone processes
Factors affecting perm afrost erodibility
Exposure to currents and wind waves
Texture and stratigraphy
Ice content, distribution and type
Slope aspect
Coriolis force
Timing and depth of thaw
Water level and temperature
Vegetation
Ice and snow cover
Groundwater
Rates and timing of erosion and recession
Overall effects of permafrost
Recommendations for research
Literature cited
Appendix A : Processes of stream bank modifications
In:
CRREL Report, 83-29
Language:
English
Keywords:
Forschungsbericht
URL:
https://apps.dtic.mil/docs/citations/ADA138410
URL:
https://hdl.handle.net/11681/9290
