THE EFFECT OF URBANIZATION ON KINETIC ENERGY DISTRIBUTIONS IN SMALL WATERSHEDS

Surface runoff and the suspended and dissolved solid loads carried from two similar watersheds are expressed in kinetic energies for a variety of rainfall events. One watershed is rural, the other urbanized, so comparison of their responses is used to determine the effect of urbanization on energy distributions. In the rural watershed, an average of only 0.053 percent of the gravitational potential energy of rainfall is converted to kinetic energy of runoff. The conversion in the urban watershed is 7.8 percent on the average, meaning substantially more of the rainfall's energy is transformed into a form which can perform erosion within the watershed. Transport of material is suspended or dissolved form from the urban watershed is tremedously higher as a consequence. In addition, urbanization changes the erosion pattern from one where dissolved loads predominante over suspended loads to one where both loads are of equivalent magnitude. Kinetic energies are also considered as functions of the recurrence interval of the events, called energy spectra. In the rural watershed for the range of runoff events monitored, significantly more kinetic energy is present in the outflow during baseflow conditions than in that from surface runoff events. Baseflow kinetic energies are 100-1,000 times larger than their runoff counterparts. After urbanization, however, the energy spectra for runoff and suspended and dissolved loads are all dominated by surface runoff. Surface runoff has from 4-200 times more kinetic energy than baseflow. Within the range of event recurrence intervals monitored, 0.02-0.15 years, dominant energies in the urban watershed generally occur at a recurrence interval between 0.07 and 0.08 years. /Author/

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  • Corporate Authors:

    University of Chicago Press

    1427 E. 60th Street
    Chicago, IL  USA  60637-2954
  • Authors:
    • Cherkauer, D S
  • Publication Date: 1978-7

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 505-515
  • Serial:
    • Journal of Geology
    • Volume: 86
    • Issue Number: 4
    • Publisher: University of Chicago Press
    • ISSN: 0009-3920

Subject/Index Terms

Filing Info

  • Accession Number: 00182787
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 12 1978 12:00AM