Research On The Impact Of Coal Mining On The Surface And Soil Environment Around The Four Lakes In South Shandong

With the high-intensity development of coal resources,a series of serious environmental problems have been brought about.Ground subsidence,ground fissures,gangue accumulation,waste gas,and waste water discharge caused by coal mining are very common.Development has a negative impact.The study area is located in the southwestern part of Shandong Province,and the administrative divisions are under Jining City and Zaozhuang City.The surrounding area of Nansi Lake is a typical area where coal mining has an impact on the environment.This paper adopts a combination of qualitative analysis and quantitative evaluation,development status analysis and environmental status analysis Combining the principles of combining status investigation and dynamic analysis,combining coal development environment and resource protection analysis,comprehensively and scientifically analyze the impact of coal mining activities and the status of subsidence caused by mining area,in order to realize reasonable planning of coal resources in Nansihu area,Provide scientific basis for orderly development,environmental protection and coordinated development of regional economy and society.This paper takes the mined-out subsidence area and soil environment in the area affected by coal mining around Nansi Lake as the research object.Through on-site investigation,sampling and testing,the soil geochemical characteristics,main ion content and heavy metal content changes,and temporal and spatial distribution characteristics are analyzed.Cluster analysis and factor analysis are performed to analyze the impact of coal resource development activities on the ecological and geological environment around Nansi Lake,and predict the future development trend of mined-out subsidence,and finally put forward corresponding prevention and control countermeasures.Obtain the following knowledge and conclusions:(1)There are many coal mining enterprises in the Nansihu area.The main mining horizons include 3 upper,3 lower,10,12,14,16 upper,and 17 coal seams,with an area of 123.20 square kilometers of mined-out area.Goaf collapse occurred in 37 coal mines,with a total area of 133.90 square kilometers.The arable land area affected by the collapse is 81.88 square kilometers,the residential area is 15.83 square kilometers,the woodland is 8.48 square kilometers,the grassland is 3.8 square kilometers,the road is 1.22 square kilometers,and the construction area is 1.35 square kilometers.(2)Using the probability integral method,by predicting the development trend of the subsidence area,coal mining will eventually lead to the formation of a subsidence basin within the coal mining area of the minefield,and the amount of subsidence will gradually decrease outward.The severity and affected area of goaf collapse are directly related to the layout of underground mining face,mining speed,and mining distance.(3)Both Cl^-and SO₄^2-in the soil in the Nansi Lake area may have been affected by mining activities,while the p H of the soil is obviously acidic in the mining area.The concentration of Cu,Zn and Cr⁶⁺in the soil has been significantly increased compared to the historical concentration,and the relatively high value area has a good correlation with the mining area of coal mines,which may be affected by coal mining activities.The soil environmental quality in the study area is generally good,and no problem of heavy metals exceeding the standard has been found.It is believed that coal mining activities in the Nansihu area have not caused the risk of soil environmental pollution in the area in the short term.The first-class soil environmental quality areas are mainly distributed in the northernmost part of the study area,central and western and central-eastern Tengzhou urban areas,which together account for more than 50%of the total area of the area.The second-class soil environmental quality area runs through the whole area from north to south and is distributed along the lake.There is no poor soil environment in the study area.(4)According to the phreatic level monitoring data during the wet and dry seasons,the phreatic level of the whole area is showing a downward trend.Firstly,it is closely related to the rapid development of urbanization and the continuous increase of industrial and agricultural water consumption;secondly,it has a certain relationship with coal mining.