Study On Temporal And Spatial Dynamics Of Groundwater In Shiyang RiverBasin

Shiyang River Basin is one of the typical Water Resource Scarcity in the Semi-Arid Northwestern China.Since the 1960s, a large-scale groundwater has been exploited. The social and economic sustainable development is restricted by eco-environment problems resulted from the long-term over-exploitation of groundwater. Therefore, the researches on groundwater in Shiyang River Basin not only have a scientific significance in applications of groundwater resources, but also have a practical and directive significance in rational use of groundwater resources and ecological recovery and construction.First, between 1984 and 2006,the levels of different groundwater monitoring wells not only have their own dynamic change model, but also have the commonness of groundwater's declining year after year. While a higher correlation exists between all groundwater levels and annual runoff in Hongya and Caiqi, the both maximal change-points occurred in 1994. Thus it is clear that the declining of groundwater monitoring wells is the most direct reflection of annual runoff decreasing year by year and the process of runoff's dynamic change will greatly affect the variation of groundwater levels.Second, water table has an obvious southwest-northeast waterlevle belts. An obvious regional difference exists in the falling extent and the falling rate of the groundwater level and it is comparatively bigger in Minqin than other regions.Third, the basin shows a high degree of spatial variability .Although there is a annual growing tendency in Basin's spatial correlation,the spatial correlation still be at the middle correlative level and it's degree of impaction on the total variance don't rise year by year.Fouth, the distribution of water table is uneven regional. The regions of which the groundwater level is less than 1325 meters are approximately 16.5 percent and between 1525 and 1550 meters are 12.9 percent.The water table in study areas is maily more higer and lower.Fifth,in the transfer of water table between neighbored types,except the transfer to the most lowest water or from the most highest water,the area of groundwater which the high water transferred into low water is growing year by year.It indicates that the water table is overall declining.Sixth,based on the data of more than ten thousand electromechanical wells in Minqin,the establishment of digital groundwater table modle using Simulation of Surface Runoff ,thus simulation result can identify the groundwater in in Minqin Oasis and is generally creditable.