SOIL EROSION--SEDIMENT YIELD RESEARCH IN PROGRESS

In discussing the great body of sedimentation research data that exist today and summarizing research in progress in this field, this report first analyzes the three components of the sedimentation process. The first component, soil erosion, varies with climate, soil, topography, and land management. Upland erosion is usually categorized into sheet, rill, and gully components; farther downstream, flood plain erosion usually includes valley scour and channel erosion. Mass wasting, including soil slippage and soil creep, is a special form of erosion that normally occurs on very steep or mountainous areas. Other aggravated erosion is caused by urban building activities, by strip and open-pit mining, and by highway and other right-of-way construction. The other two components of the sedimentation process are soil transport and soil deposition. The amount of suspended sediment transported by rivers to the sea each year is tremendous. It has been estimated that the average annual fluvial- sediment discharge to oceans and estuaries from the conterminous U.S. for the 20-year period 1950-69 was 491 million tons. Bed load was estimated to be an additional 10% of the suspended sediment transported. The second half of this report refers to research in progress, or just completed, that analyzes variations in sediment yield, determines the effectiveness of various conservation practices, develops equations for estimating sediment yeilds, and summarizes sediment yield modeling. In conclusion, the authors found (1) considerable work and excellent progress in research to isolate and quantify basic variables affecting erosion, including methods of determining soil erodibility; (2) much-needed effort to identify problem areas of mass wasting and to quantify sediment yield from these sources; (3) good research on erosion due to construction, including a quantification of the sources of this type of erosion (as well as regulations designed to control such erosion); and (4) some excellent work on developing models for predicting sediment yield. They also noted several advancements in measurement technology. Included are several new devices for measuring bedload, several excellent automatic pumping samplers, and other equipment to measure sediment yield more accurately.

  • Corporate Authors:

    American Geophysical Union

    1909 K Street, NW, Division of Hydrology
    Washington, DC  USA  20006
  • Authors:
    • Heinsemann, H G
    • Piest, R F
  • Publication Date: 1975-3

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Filing Info

  • Accession Number: 00084681
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 7 1975 12:00AM