Time-Parameter Estimation for Applicable Texas Watersheds

Details

• Creators:
  Roussel, Meghan C ; Thompson, David B. ; Fang, Xing ; Cleveland, Theodore G. ; Garcia, C Amanda
• Corporate Creators:
  United States. Geological Survey. Oklahoma-Texas Water Science Center
• Corporate Contributors:
  Texas Department of Transportation. Research and Technology Implementation Office
• Subject/TRT Terms:
  Design Drainage Rainfall Runoff Watersheds
• Publication/ Report Number:
  FHWA/TX-05/0–4696–2
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Texas
• Edition:
  Technical Report September 2004–August 2005
• Corporate Publisher:
  Texas. Department of Transportation
• Abstract:
  Characterization of hydrologic processes of a watershed in the context of drainage design requires estimation of specific time-response characteristics. The time-response characteristics of a watershed frequently are represented by two conceptual time parameters, the time of concentration and the time to peak discharge. The study described in this report assesses various approaches for estimating watershed characteristics necessary to estimate time of concentration for applicable Texas watersheds, assesses various established approaches of estimating time of concentration, describes a preferable approach for time of concentration estimation, and evaluates the conversion of values of time of concentration from the preferable method to values of time to peak. A comparison of various approaches (manual and automated) for estimating watershed characteristics indicates that time of concentration is relatively insensitive to the specific approach. For the 92 watersheds considered in the study (applicable watersheds), drainage areas are approximately 0.25 to 150 square miles, main-channel lengths are approximately 1 to 50 miles, and dimensionless main-channel slopes are approximately 0.002 to 0.02. Based on the analysis, the preferable approaches for estimation of time of concentration are the Kirpich-inclusive approaches and more specifically, the Kerby-Kirpich approach for applicable watersheds. The preference is based on simplicity of approach and ease of input-data acquisition. The Kerby-Kirpich approach is straightforward to use and produces time of concentration values, which, through the conventional Natural Resources Conservation Service conversion, mimic time to peak from auxiliary analysis of observed rainfall and runoff data for the 92 watersheds. Comparison of time of concentration and time to peak values substantiates the preferable method. Visually fitting a linear relation between time of concentration and time to peak indicates that alternative conversions to the Natural Resources Conservation Service conversion are more appropriate when the Kerby-Kirpich approach is used.
• Format:
  PDF
• Funding:
  0–4696
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:1d4836d6465d1d163e9be54c9995ac6aff2683ed0b484c9e88bd5f5b0dcd99446d49c4426155509975abcecaf544546644dab1f72df45add42bdaf19550a7742
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88540/dot_88540_DS1.pdf
• File Type:
  [PDF - 3.41 MB ]