LOW FLOW MODELING IN SMALL STEEP WATERSHEDS

On some small steep mountain watersheds the magnitude of low streamflow is almost uniform for prolonged periods. Thie phenomenon is exhibited by three small drainage areas within the Entiat Experimental Forest of central Washington State. On these watersheds about two-thirds of the annual precipitation is in the form of snow. Annual hydrographs for each area are characterized by an almost uniform flow with a complex snowmelt hydrograph superimposed between March and August. The only distinct recession curve occurs at the end of the snowmelt season and continues to decrease until a relatively uniform streamflow typified by the watershed is reached. In a computer simulation study of the three drainage areas, a linear groundwater reservoir submoldel based on the recorded streamflow recession curves was found to be inadequate during low flow periods. Modifications to the subsurface part of the simulation model to improve the representation of the prolonged period of relatively uniform low flows are described in this paper.

Media Info

  • Features: Appendices; Figures; References;
  • Pagination: p. 1225-39
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00141801
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #12374
  • Files: TRIS
  • Created Date: Jan 16 1977 12:00AM