Accession Number:

ADA106253

Title:

Adjustment of Peak Discharge Rates for Urbanization.

Descriptive Note:

Technical paper,

Corporate Author:

HYDROLOGIC ENGINEERING CENTER DAVIS CA

Personal Author(s):

• Gundlach,David L.

Report Date:

1979-02-01

Pagination or Media Count:

9.0

Abstract:

Various investigators have shown that changes from rural to urban conditions within a watershed, in general, significantly affect flood flows. Recorded annual peak discharge rates or peak discharge rates above a given base for a basin that has been undergoing a change in land-use conditions represent a nonstationary time series. The series must be adjusted to a specific land-use condition typically present conditions prior to performing a statistical frequency analysis. It was the aim of this note to present a procedure utilizing a single event rainfall-runoff model for transforming recorded peak discharges at a gaging station to a consistent set that reflects existing land-use conditions. Methods presented can be used as a guide to determine an existing-condition discharge frequency curve of annual peaks or peak discharge rates above a given base when utilizing a single event rainfall-runoff model. The multiplan-ratio option of HEC-1 permits the user to calculate systematically the hdyrologic response of several storm events for a given set of land-use conditions. The adjustment procedure described is also applicable when predicting runoff for estimated future conditions. Author

Descriptors:

• *PEAK VALUES
• *WATER FLOW
• *WATERSHEDS
• *URBAN AREAS
• *URBAN PLANNING
• TIME SERIES ANALYSIS
• RATES
• STORMS
• RAINFALL
• LAND USE
• BASINS(GEOGRAPHIC)
• RUNOFF
• FLOOD CONTROL
• RURAL AREAS

Subject Categories:

• Hydrology, Limnology and Potamology
• Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE