Study On Water Environmental Characteristics And Water Quality Evaluation Of Closed Coal Mining Subsidence Area

China's coal mining methods are mainly based on well mining.In the Huai he River Basin in North China Plain,the phreatic water level is high and the coal beds are covered with thick loose layers,forming large-scale coal-mining subsidence areas,although the cheeks are reduced sharply.,changed the original local hydrological cycle model,but provided a large area of available water resources for the local area,and the rapid evolution of the subsidence area at small time scales(several years to decades)can also be regarded as The rapid evolution of special lakes.Coal mining subsidence areas will gradually increase their water depth and area with coal mining activities.According to whether the water area and the surface rivers are connected,the subsidence water will be divided into open and closed water areas,and open water areas.The water quality and quantity of water change greatly due to the impact of rivers,and its evolution rules are complex and changeable.It is difficult to obtain the evolution rules of the subsidence area itself;whereas the closed coal mining subsidence area is surrounded by only surface runoff,the wireless water flow The replacement of waste water,and the discharge of industrial sewage and domestic sewage,can represent the law of the change of water quality and water volume in the subsidence area of coal mining.Therefore,the study of the characteristics of water environment in closed coal mining subsidence areas and the evaluation of water quality not only provide evidence for the study of the evolution of water quality in subsidence areas,but also provide references for exploring the evolution of natural lake water quality.Therefore,the paper selects the closed coal mining subsidence area in Huainan as the research object and uses the water accumulation area of the Mazhuang Coal Mining Subsidence in the Panjipan ? Mine as an example to carry out a continuous one-month on-site investigation of the water environment and water quality monitoring.The characteristics of water environment time and space evolution,agricultural non-point source input,rainfall,and temperature are the main influencing factors of water quality in subsidence areas.The subsidence areas are "shallow-water lakes ",and the surrounding land use types and land types before the accumulation of water are of space for water quality.The distribution has a certain influence;a variety of evaluation methods are used to evaluate the water environment,and the water environment in the subsidence area is in the category ???.It is still clean or clean,there is no organic pollution,the nutrient status is medium nutrition,and it belongs to phosphorus.Restricted waters.It provides a theoretical reference for the protection of the local water environment,the recovery and management of subsidence areas,and the functions of water irrigation and fish farming.