Sensitivity Analysis in Parameter Calibration of the WEAP Model for Integrated Water Resources Management in Unda Watershed

WEAP or Water Evaluation and Planning is a model that is used to simulate integrated water resources management. To get a model that is able to represent the real condition, a calibration process is needed. This study aims to determine the optimum parameter value through sensitivity analysis and to determine the parameter value to obtain the optimum model reliability value during the calibration process. Based on the sensitivity analysis process for several calibration parameters of the WEAP model, it is found that some parameters have similar characteristics. Change in Z1, DWC, RRF, RZC value is directly proportional to the RMSE value, the greater the parameter value, the greater the RMSE value obtained. Whereas change in Z2, DC, SWC, PFD value is inversely proportional to the RMSE value, the larger the parameter value, the smaller the RMSE value obtained. After the sensitivity analysis was carried out, the efficiency coefficient of the Nash Sutcliffe model was obtained 0.512 which was satisfactory. The Index of Agreement and the correlation coefficient of calibration also show good results with values of 0.848 and 0.743. From these results, it can be concluded that the WEAP model for the Unda watershed is satisfactory.