Using Limited Observations to Inverse Dynamically Groundwater Spatial Distribution: A Case Study from the Lower Reaches of Tarim River, China

Tarim River is a typical inland river.Riverbank plant communities mainly depend on the flood and groundwater to maintain their growth. The groundwater table depth, one of eco-environment factors, determines constitution, distribution and growth of natural plant. Since 2000,continuously monitoring of groundwater has been carried by Tarim River Management Bureau and Xinjiang Institute of Ecology and Geography, Chinese Academy of Science, with setting cross section and observation wells, and some pertinent researches and analyses have been done (Chen et al., 2003, Deng, 2005). Using limiting observation data to inverse groundwater spatial distribution will play a more dominant role in rational evaluation and scientific ecosystem management in the lower reaches of Tarim River. In this paper, the groundwater flowing processes and the water-table fluctuating processes during the past 3 years were simulated to obtain the spatial and temporal distribution of groundwater table by means of the GIS-assisted FEFLOW modeling based on the Digital Elevation Model data (DEM) and hydrogeologic data obtained in the Alagan section, one representative section of 12 groundwater monitoring sections, in the lower reaches of Tarim River. The model can be applied with relatively limited data to reappear the dynamic change of groundwater. Then groundwater table and calculated groundwater table depth can be used to analyze the relationship between groundwater and eco-environment. The results of model showed that groundwater was affected by river leakage, the main effective transverse region was 1.0 km from the river and within this effective region the groundwater depth was below 9 m.