Abstract:

When the drawdown of groundwater is a bit more than the suitable water-level of native vegetation will cause risk of vegetation, quantitative evaluation of the ecological risks can provide guidance for the vegetation ecological environment protecting and sustainable exploitation of groundwater resources. Take an example of Wulannao water resources,the research is based on a great deal of the vegetation sampling survey and hydrogeological field survey results, selects the Gaussian regression analysis method base on the mathematics of vegetation ecology to analyze the depth to groundwater table and data of vegetation, obtain the mathematical relationship model and suitable ecological water-depth of Wulannao, and build indicators of ecological risk assessment which variable is the depth to groundwater table. Build up the numerical model of groundwater flow of study area. Use the model to select exploration program and predict flow net of future period. On the basis of changes in the level of water table causes by groundwater exploration, calculate the ecological risk of vegetation and part study area into different risk zone. From the result of risk assessment under current exploration condition can see that 70% of research area is safe zone and low risk zone. According to the suitable ecological water-depth to make recommendations to the middle-risk zone and high-risk zone.

Key words: groundwater numerical simulation, suitable ecological water-level, vegetation ecological risk, groundwater, exploitation, Ordos basin