Water Quantitytransportation And Water Quality Character Between Surface Water And Shallow Groundwater In Coal Mining Subsidence In Panji And Xieqiao Area

Huainan is situated at plain north of Huaihe, which has rich coal reserves, many thick and steady coal seams. Thick quaternary alluvium including aquifer and Impermeable layer covers on the coal seams, long time of exploitation caused large number of subsidence area, and different connection of hydraulic and quality appeared between suface water, shallow ground water and river. According to the relationship between subsidence water and river, two typical subsidence areas---open and closed subsidence water area----were named, and the dynamic development between surface and shallow ground water is the key of utilizing and protecting water of subsidence area.Open and closed subsidence water area were selected, and hydrogeological condition was analyzed and on the base of dynamic datas of water level between surface water and shallow ground water, type of ground water was confied as confined aquifer proved by large number of monitoring data, and two types of models were constructed to soluble, and hydrogeological parameters were identified, the process of transportation between surface water and ground water was calculated using Programm of finite element method and water quantiy transported between surface water and shallow ground water was studied to get the transportation rule of them.At the same time, water samples were collected and monitored of the two types subsidence area, the water quality was evaluated by several assessment methods such as single factor, fuzzy clustering, Nemerow and so on, then nitrogen was the characteristic indexes, using isotopic analysis to determine the source of nitrogen. Water variation with time and space beween surface water and shallow ground water and the main factors were studied using correlation analysis. Water quality of these two types subsidence area fluctuated between â…¢-â…¤ calss, ammonia was the characteristic index of shallow groundwater and total nitrogen in surface water, resource of nitrogen showed closed subsidence area was relatively isolated and the recycle contion was weaker than open subsidence area, then the pollution disperal concentration was lower than open subsidence area, although these two types subsidence water were all phosphorus limited type water. Factor such as precipitation, evaporation, input of agricultural nonpoint pollution human, fishery and solid waste could affect water quality variation between surface water and shallow groundwater, the risk of being polluted increased because of the frequent transportation.