The Study On Numerical Model Of Groundwater Flow And Urban Water Supplyment Safety In Three Districts And Suburbs Of Baotou City

With the acceleration of urbanization, water resources cannot meet the demand of city, seriously hampered the further development of city, urban water supply security gets more attention.Baotou is a serious water shortage city. Currently it relies on the Yellow River water supply mainly, but there is a certain risk in Yellow River water supplement, thus, the Baotou city may suffer from water supply crisis, and this is harmful to the social stability and economic development. This paper established the groundwater flow model of three districts and suburbs of Baotou City, and on this basis of the study , area water supply security is studied.Firstly, According to the data from October 2008 to October 2009, the Groundwater Model System (GMS) software is used to construct the hydrogeological conceptual model of the three districts and suburb of Baotou City. Coupled with the application of MAPGIS, ARCVIEW, a large number of data about sources and sinks are processed by ACCESS and VBA programming into specific format which is required by GMS, and then the numerical model of groundwater is build up. The results obtained are as follow: in the simulation period, the total amount of the groundwater recharge is 17233.81×104m3/a and the total amount of the excretion is 25448.94×104m3/a, Therefore, the change of the groundwater storage is negative, about -6271.16×10~4m~3/a. Next, the study about water supply security was proposed. Considering 2020 as the situation of extremely dry year, the water supply and demand balance is progresses. By analyzing, when water supply crisis occurs, the exploitation of the groundwater should be increased, about 7077×10~4m~3/a, it is allocated to the Qingshan water plant (located in the upper of Kundulun alluvial fan). The groundwater flow model is used to predict the change of the groundwater level and the recharge and discharge terms. The results indicate that the dewatering level of the unconfined aquifer water is acceptable, so the plan is feasible. Under the emergence situation, in 2020, the amount of total recharge is 8437.27×10~4m~3/a, and total discharge is 27637.13×10~4m~3/a, the change of the groundwater storage is negative, about -19199.87×10~4m~3/a.From the above analysis, the rainfall infiltration and lateral inflow of northern piedmont are the dominant recharge source, and the extraction is the dominant discharge way. In the emergency period, since the increment of the groundwater extraction, amount of storage capacity of the unconfined aquifer is consumed. At last, the suggestion for the security of water supply in Baotou City is proposed, which provides a reference for the Baotou water supply.