COMPUTER-AIDED CATCHMENT CALIBRATION : DEVELOPMENT AND APPLICATION

Abstract

A series of new features has been introduced into the knowledge-based system for Storm Water Management Model, KBSWMM (Lum 1990; Liong et al. 1991a; Liong et al. 1991b). The new model, KBSWMM2: ( 1) is developed with version 11 of X Window System, Xll; (2) includes the Extran block, in addition to the Runoff block, of SWMM. The inclusion of Extran block allows users to apply KBSWMM2 to catchments under backwater impact; (3) has a new catchment calibration approach based on the Response Surface method. This approach is to yield the global optimum values for the calibration parameters. The application of the user-friendly KBSWMM2 was demonstrated on two catchments in Singapore, the Upper Bukit Timah (UBT) catchment and the Mid-Bukit Timah (MBT) catchment. The UBT catchment has a long hydrologic record; thus, the proposed calibration approach was tested on this catchment. The results are highly promising. For wider applicability the approach should be tested on other catchments. The telemetric equipments for water level and rainfall measurements at the MBT catchment have only been recently installed. Thus, only limited valuable data can be used for study. With the limited simulation runs conducted in this study, KBSWMM2's simulated water level compare satisfactorily with their counterpart.