RAINFALL DEPTH-DURATION-FREQUENCY RELATIONSHIPS FOR DRAINAGE DESIGN IN DEVELOPING COUNTRIES

One possible approach is described of the problem of construction a rainfall depth-duration-frequency relationship for a location in which the density of recording (autographic) rain gauges is low and/or the length of the available records is short. The properties of heavy rainfall in short periods are summarized, and methods of generalizing rainfall depth-duration-frequency relationships are discussed. The application of such generalized relationships to Portuguese Timor is described and the results are assessed. The procedure adopted in the application of relationships to Timor, involved the computation of reduction coefficients based upon the 2-year, 1-hour rainfall totals estimated by equations proposed by Bell. In order to synthesize the rainfall depth-duration-frequency relationship using the method proposed by Bell, the mean annual maximum observer-day rainfall total, and the mean annual number of thunderstorm-days are required. The study results show that subject to verification of equations at higher altitude sites and certain restrictions on duration and recurrence interval, the indirect method of synthesizing rainfall depth-duration-frequency relationships proposed by Bell may be applied to any station listed in the Annurio Climatologica de Portugal for which the mean annual maximum observer-day rainfall depth and the mean annual number of thunderstorm days can be estimated. The results are also discussed of an investigation of the possibility of extending the method to sites at which no meteorological observations are made.

  • Supplemental Notes:
    • Proceedings of the Seminar on Highway Design in Developing Countries held during the PTRC Summer Annual Meeting, 10-11 July 1975 at the University of Warwick, England.
  • Corporate Authors:

    Planning and Transport Res and Computation Co Ltd

    167 Oxford Street
    London W1R 1AH,   England 
  • Authors:
    • Hall, M J
  • Conference:
  • Publication Date: 1975-7

Media Info

  • Features: Figures; References;
  • Pagination: p. 107-117
  • Serial:
    • Issue Number: 5

Subject/Index Terms

Filing Info

  • Accession Number: 00144041
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Dec 22 1976 12:00AM