REPORT OF SUB-COMMITTEE ON EROSION

THE FACTORS THAT APPEAR TO BE MOST IMPORTANT IN DETERMINING EROSION, AND THAT REQUIRE THE MOST INTENSIVE RESEARCH, ARE: (1) THE ERODIBILITY OF EXISTING SOILS, (2) THE DIMENSIONS AND DEGREE OF SLOPE OF BARE SOIL AREAS, (3) THE VELOCITY AND VOLUME OF SURFACE WATER REACHING THE HIGHWAY FROM ADJOINING LANDS, DEPENDING ON LAND USE, (4) THE DESIGN OF HIGHWAY SLOPE AND DITCH SECTIONS AND OF HIGHWAY DRAINAGE STRUCTURES, AND (5) TYPES OF GROUND COVERS EXISTING OFF THE HIGHWAY AND EXISTING OR ESTABLISHED UPON ERODIBLE AREAS WITHIN HIGHWAY LIMITS. IN THE PAST THE FOLLOWING FACTORS HAVE CONTRIBUTED TO HIGHWAY EROSION: (1) HIGHWAY SLOPES HAVE BEEN TOO STEEP FOR STABILIZATION OF EXISTING SOILS AND HAVE THUS PREVENTED READY ESTABLISHMENT OF VEGETATIVE GROUND COVER. (2) HIGHWAY CROSS SECTIONS HAVE FEATURED STEEP SLOPES WITH FLAT PLANE SURFACES THAT HAVE TENDED TO ENCOURAGE EROSION. (3) HIGHWAY SLOPES AND SHOULDER AREAS HAVE NOT BEEN PROVIDED WITH PROPER SUBSURFACE DRAINAGE. EARTH SLUMPAGE AND SLIDES HAVE RESULTED. (4) TOPSOIL HAS NOT BEEN CONSERVED DURING CONSTRUCTION OPERATIONS AND STERILE SOIL SURFACES HAVE BEEN LEFT UPON WHICH VEGETATION CANNOT BE ESTABLISHED UNTIL FERTILITY IS RESTORED. (5) DITCH SECTION, CULVERT, AND INLET AND OUTLET DESIGN HAVE IN SOME CASES FAVORED SURFACE SOIL EROSION ON HIGHWAY LANDS. THREE DEMONSTRATION PROJECTS AND FOUR SPECIFIC RESEARCH PROBLEMS ARE PROPOSED.

  • Authors:
    • Aust, F A
  • Publication Date: 1938-3

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Filing Info

  • Accession Number: 00204868
  • Record Type: Publication
  • Report/Paper Numbers: pp 8-12
  • Files: TRIS
  • Created Date: Jan 17 1972 12:00AM