The numeric simulation and the per-protocol analysis of the combined use of surface and ground water in Shijin district of Hebei province

The groundwater level has been descending continuously in Shijin irrigation district of Hebei province.The hydrogeological conditions of Shijin Irrigation System were analyzed,and a 3Dtransient surface-groundwater interaction model was established using MODFLOW software.The model was calibrated against observed groundwater level data.The results show that the model performance is acceptable and it can be used to simulate and forecast the groundwater dynamic of Shijin irrigation district.The model was applied in the well irrigation area and in the well-canal combined patterns region.Considering the well irrigation times,the well irrigation quota and the canal irrigation quota of the factors and so on,five kinds of schemes were put forward.The results show that the second scheme is the best.The well-canal combined patterns and adjustment of the time of irrigation should be used in Shijin irrigation area.The well irrigation patterns should be arranged in March,the well irrigation quota is45m3/h;the well-canal combined patterns should be arranged in May and October,and the canal irrigation quota is 1 800m2/hm2.It is simple and effective to control the groundwater level and to improve water efficiency in Shijin irrigation district.