Research On Recharge Ways Of Fissure Water Resource In Donggaodi Area

Rocket Base, namely Chinese Research Institute of Carrier Rocket, is located in Donggaodi area of Fengtai District, Beijing. Owing to historical conditions and geological location, the water for local production and living has been taken from self-provided wells by exploiting pore water from the local Quaternary aquifer. However, Quaternary pore water have been worsening in the recent years, it is not suitable for drinking. Under such conditions, Chinese Research Institute of Carrier Rocket entrusted Beijing Institute of Geological Engineering(BIGE) with the scientific research on the groundwater resource, trying to take the karst fissure water concealed in the bedrock under Quaternary aquifer as water source, and studying the feasibility. Research on recharge ways of karst fissure water in Donggaodi area has been carried out. Since the study level was lower in the past, there are only general knowledge about recharge, runoff and drainage of the local karst fissure water so far. It is thought that Cambrian karst fissure water in the local area is mainly recharged by side runoff from upstream water, having no obvious relationship with the local Quaternary water. Based on the stable isotope analysis, radioactive isotopic age determination, pump test, groundwater level trends analysis and many other ways, the paper discusses genesis of the water concealed in the bedrock in Donggaodi area, and set up preliminarily the concept model of recharging Cambrian karst fissure water, that is, the basic source of the water concealed in bedrock of the research area is atmospheric precipitation in the city of Beijing. There are two kinds of recharge ways, one is flow of the water concealed in bedrock from the upstream, another is leakage recharge from the local Quaternary pore water. For the groundwater in different depth, the water from two kinds of recharge ways constitute different contents of the total recharge amount. The shallow fissure water in bedrock is mainly recharged by leakage of above Quaternary pore water, and secondly, by side runoff of the water in bedrock from faraway place(upstream). Naturally, the deep fissure water in bedrock is mainly recharged by side runoff of the water in bedrock from faraway place(upstream), and secondly, by leakage recharge from the shallow fissure water concealed in bedrock. As amount of the exploited deep fissure water in bedrock is larger in recent years, the shallow fissure water in bedrock occupies more proportion in the deep fissure water in bedrock by vertical recharge. At last, in total recharged water for Cambrian karst fissure water, the local Quaternary fissure water occupies more and more proportion by leakage recharge from shallow fissure water, that is the result. The research on recharge ways shows that fissure water concealed in bedrock in the research area is related to Quaternary aquifer, it is obvious that leakage recharge is from Quaternary pore water to the fissure water in bedrock. One-sided knowledge of recharge water resource of carst fissure water in the research area is corrected by the conclusion, the basic direction of recharge resource measurement is clear. The work provides basis for deep research on recharge resource of karst fissure water and appraisement of exploitation amount of the karst fissure water in Donggaodi area.Since Quaternary pore water and karst fissure water in bedrock from the research area have worsened in quality, the data of hardness and solving solid are high, several data even higher than national standard, the paper raises concrete ways for protecting the water concealed in bedrock, in order to avoid worsening quality of the water in Donggaodi area by leakage recharge from Quaternary water. The two kinds of protection ways are controlling exploitation of the fissure water in bedrock and paying attention to the construction.