Numerical Simulation On Karst Groundwater Protection In Northern China

On the Northern China platform, off the east of Helan—Liupan mountain, to the south of Shenyang—Yinshan mountain, take Huai river and Yellow Sea—Tan-Lu fault as the north and west edge. Where distributed68.5x104km2carbonate rocks, which contains karst groundwater with a volume of108.8x108m3/a. The Karst groundwater play a very significant role as load bearing in people’s daily life and production. But with the increasing human activities, the karst groundwater in quality and quantity are facing increasingly serious threat. So it is necessary to take human intervention to protect groundwater resources, for the purpose of achieving the quality and quantity can satisfy the requirements of sustainable development of human.This paper selected the typical karst groundwater system in northern China-Shanxi’s Niangziguan spring area, with system theory as the guiding ideology, aimed at the karst groundwater resources protection as research direction. Use the FEFLOW software as the main tool, based on the aquifer medium characteristics of research area and the groundwater movement characteristics of spring area, Simplified the system boundary and the process of supply、runoff and drainage, established a concept model, and then use a set of strict mathematical equation to describe concept model. After that chose a suitable simulation time, given the solution conditions, figured out the equations and validated the model in FEFLOW. Acquired a approximate expression of groundwater flow system in the numerical model and a set of parameters of groundwater aquifer system which can reflect the characteristics of medium characteristics. Finally, using response matrix method as mathematical foundation, to balance supply and spring protection as the ultimate goal, put forward the concept of groundwater quantity vulnerability and established classification standard. At last, applied the established model and parameters according to the grading standard to calculate water quantity vulnerability, and delineated the karst groundwater quantity protection area.In the course of the study, this paper obtained the following results:1, Set up the North China typical karst groundwater system-Niangziguan spring area2-D flow numerical model.2,In view of the present groundwater vulnerability concept ignored problems of water quantity, separated " water quantity vulnerability" from groundwater vulnerability concept, undertook preliminary definitions and proposed classification scheme.3, Applied the numerical model and the water quantity vulnerability concept and its dividing standards, got a balanced between the water supply and spring flux as the goal, carved out the water protection area.