Water Resources Research Act Program

Details for Project ID 2006HI144B

Hydrologic Analysis of Hawaii Watersheds for Flood Control and Water Quality Management

Institute: Hawaii
Year Established: 2006 Start Date: 2006-03-01 End Date: 2008-08-31
Total Federal Funds: $35,905 Total Non-Federal Funds: $72,357

Principal Investigators: Clark Liu

Abstract: The principal objective of this proposed research is to develop techniques of watershed modeling based on the linear systems theory. The new modeling techniques allow a ready simulation of flood runoff and pollutant loading generated by a watershed with given rainstorm input. Modeling rainfall-runoff processes in Hawaii watersheds is a major challenge because the watersheds have steep slopes and small drainage area and because the watersheds often experience short-duration and high-intensity storms. Currently, the rational formula is used for urban drainage design, and whereas the more sophisticated unit hydrograph method is used for the analysis and design of major flood-control facilities. The unit hydrograph method is based on the linear systems theory. According to this theory, the instantaneous unit hydrograph (IUH) of a watershed characterizes its response to rainfall. After the IUH of a watershed is constructed, runoff generated by future rainstorms in the watershed can be calculated by a convolution integration of IUH and rainfall input. Like IUH, an instantaneous pollutograph (IPG) can characterize the watersheds response to rainfall and pollutant input. After the IPG is constructed, waste loadings generated by future rainstorms in the watershed can be calculated by a convolution integration of IPG and rainfall input. In this project, IUH and IPG will be derived and applied for selected Hawaii watersheds.