Runoff continuous simulation of a large rural watershed with automatic calibration

In general, SWMM is known to be applicable only to runoff simulation in urban watersheds, but it can be used to continuously simulate runoff in large rural watersheds. In order to apply SWMM to rural watersheds, it is necessary to estimate the parameters of the groundwater and aquifer menus. However, it is difficult to estimate the parameters of groundwater and aquifer menus because there are some of conceptual and uncertain parameters. These parameters should be estimated through model calibration procedure. To verify the applicability of the runoff continuous simulation for rural watershed, SWMM was performed for 10 years period in the Namgang Dam Basin, Korea. The observed data used to calibrate the model is the inflow of the Namgang Dam and the parameters are automatically estimated using SWMM-SCE, an automatic model calibration program. There’re twenty-two estimation parameters of watershed runoff simulation including twelve parameters in the groundwater and aquifer menus. NSE (Nash-Sutcliffe efficiency) and AME (absolute mean error) are used for objective function. The results of SWMM simulation are compared with the results of TANK model simulation of the same watershed.
 

This was presented as a poster