Modelling of regional groundwater flow of the Chaiwopu Basin and the river valley in the Urumqi River catchment

Groundwater in the Chaiwopu Basin and the river valley provides important sources of water supply for the city of Urumqi.For the purpose of formulation of sustainable groundwater development plan,a regional groundwater flow model was constructed for the area.Hydrogeological parameters were calibrated against observed groundwater level hydrograph and flow field.The model was used to analyze the flow system,groundwater balance,changes in groundwater levels and direction of groundwater monitoring.The results of this study show that there are two dominant regional flow systems in the area: one is along the main course of the Urumqi River;another is the capture zone of the Chaiwopu Lake and the Salt Lakes.Large groundwater storage could adjust seasonal variations in groundwater recharge and impacts of groundwater abstraction,resulting in stable groundwater level variations and a gradual decline.Current groundwater level observation wells are located in discharge areas and river valley.It is very important to have also observation wells in recharge areas along the main river alluvial fans and mountain front zones.Observation of spring discharge will provide valuable information for better calibration of the groundwater flow model.