CALIBRATION AND VALIDATION OF PMWIN MODFLOW WITH TANDO MUHAMMAD KHAN DISTRIBUTARY COMMAND AREA

Abstract

Since Sindh is in the lower reaches of the Indus River, it is most vulnerable to a variety of upstream water development challenges. To overcome these challenges, HEC has launched the project “Sustainable Freshwater Management (LIB) for Irrigated Agriculture in the Lower Indus River Basin”. Under the umbrella of this project, Muhammad Khan's distributary was selected as the study. The aim of this study is to Calibrate and validate PMWIN MODFLOW with Tando Muhammad Khan distributary command Area to highlight the groundwater potential. Documented pumping test data located in Muhammad khan distributary command area was simulated in PMWIN MODFLOW software to determine Sustainable usage of groundwater. For PMWIN MODFLOW the input data was obtained from distributary via pumping test and from already calculated data from various literatures. There were two tube-wells (head and tail); both were given no flow conditions in boundary conditions of mesh. The head values obtained at different intervals were used to calibrate and validate as well. Discharge was kept 70.5 m3/hour. The calibration was performed on a single time whereas for validation two simulated runs were generated. To verify the results, the root mean square deviation was calculated which states that the results are less than 10%. Time versus Hydraulic Head graphs presented to illustrate the conclusions graphically of the calibration and validation of the model.

Keywords- Muhammad khan distributary, Lower Indus Basin (LIB), PMWIN MODFLOW, Calibration and Validation.