Research Of Theevolution Of Ordovician Karst Water Environment In The Feng Feng Coal Mining Influence

Water resources is the irreplaceable material base for human being, groundwater is the most important drinking water source. Karst water because of water, good quality, was considered the most reliable and the highest quality of drinking water source. For the karst regions in the North China, the strong drainage of the coal mining process has evolved into the most important drainage way.Fengfeng coal mining area as the north is representative of the large and medium-sized coal mine, for coal mine of Ordovician karst groundwater environment evolution of the in-depth study, from of recharge, runoff and discharge and water chemistry field and conducted a comprehensive analysis. The change of filling method,(1)Due to the coal mining caused the water level decline, resulting in the Fuyang River by limestone exposed reverse supply and ground subsidence caused the overlying aquifers of the karst water recharge, runoff area of local groundwater flow system development and retention area increased, underground watershed boundary change, change of groundwater seepage field, the formation of new local hydrogeological sub unit, karst water system has by natural springs excretion evolved into mine drainage and artificial exploitation excreted mainly type.(2)The water flow velocity of the karst water is obviously slow and the hydraulic gradient is large.. The evolution of the water system is a single water flow system, the strong runoff zone disappears, the medium runoff zone and the weak runoff belt develop. The karst water evolved from the high K++Na+, then gradually to the high SO42-, and the regional groundwater flow characteristic of the high salinity was evolved.. The change of water chemistry field,(1) karst water chemistry characteristics to develop in the direction of pore water, type, tend to complicate; macro ions K+ + Na+, Mg2+, SO42-, mineralization degree and total dissolved solids concentrations were significantly increased, dissolved more heavy metal elements.(2) enhanced karst water dissolved mineral dissolution ability, more dolomite.(3) the water quality of karst water is deteriorating, and some areas are obviously polluted, and the pollution index is sulfate and heavy metals.Using a combination of environmental isotope tracer and hydrogeochemical way, a preliminary study found that coal mining of karst water chemistry pollution ways:(1) the main source in mining production chain such as power coal and other airpollutants are rainfall directly into the exposed bedrock recharge area access recharge;(2) only in obviously collapse area are the top pore water and coal and sandstone water leakage recharge.