Groundwater Dynamic Response Study Of Coal Mining In Shanxi Wind Sand Area

Yulin city is a national energy base in heavy industry, also is the main support regional economic development of Shaan Xi province. Its mineral resources are abundant, but the lack of water resources. UNESCO designate Shanbei region in one of the emphasis of the water shortage area. Industrial and agricultural production and local residents drinking heavily reliant on groundwater resources, how to protect the area in the process of coal mining with water supply significance of groundwater resources should be extremely important..This thesis uses the embedded depth of groundwater data of 12 observation Wells between 29 years(1980-2008) yu Yang area and hengshan town of yulin area as the foundation, draw the embedded depth of groundwater depth contour map, changing with time curve, combined with the natural geographic and geological background condition of yulin city, hydrogeological condition and human activity effect, reveal the dynamic change rules of groundwater, determine the main influencing factors of groundwater dynamic change. On this basis, the use of fuzzy clustering analysis method to study the type of groundwater, and analyzes the main characteristics of each type. Finally gives the Suggestions and measures for the sustainable development of groundwater resources.In this thesis, we get the following conclusion:(1) Groundwater depth of Yuyang district and Hengshan County in space is generally increases gradually from northwest to Southeast, at the time, overall the groundwater level downward trend. During the period of 1980-1990 years, the groundwater level stay stability. In 1991-2000 years, the groundwater level declines slowly, and in 2001-2008 years, the groundwater level decreased significantly, the 301 observation wells in 2008 suddenly dropped by 6.4m. The groundwater of observation wells of desert area in the lag time of water level change relative rainfall shorter than the sand loess area.\(2)According to the fluctuation of groundwater level, using Fuzzy cluster analysis method, the dynamic types of groundwater level is divided into 3 categories, namely, water level changes strongly type, medium changes type water and weak changes- basically stable variation type. Ba Lasu、Mahe town is located in the the study area and other areas of the observation well(404, 406,etc.) belongs to the level of strongly change type, variance than other two kinds, maximum variance of series is 0.45, the fluctuation of water level gradually strongly, in the 1980-1990 years maximum amplitude difference and the minimum monthly amplitude difference are 0.24~0.44 m and 0.04~0.10 m, for 1991-2000 years are 0.30~0.44 m and 0.10~0.14 m, during the period of 2001-2008 for 0.35~0.56 m and 0.12~0.17 m.In the research area of Xiao Haotu、Meng Jiawan twon,the observation wells(405, 409, etc.) belong to the middle type. the variance is between the change of two type, maximum variance is 0.16. During the period of 1980-1990, 1991-2000, 2001-2008 years, the maximum monthly amplitude difference and the minimum monthly amplitude difference are 0.15~0.27 m,0.2~0.28m;0.35~0.54 m,0.02~0.10m;0.07~0.12 m, 0.04~0.14 m.In the study area of Jin Jitan, Ma Huangliang area, depth of the observation wells(429, 417)is deep, the fluctuation of water level is not obvious, which belongs to the weak variation-basically stable level, its variance is minimum, the maximum variance is only 0.06. During the period of 1980-1990, 1991-2000, 2001-2008 years,the maximum amplitude difference and the minimum monthly amplitude difference were 0.10~0.17 m, 0.05~0.19m;0.07~0.22 m, 0.01~0.09m;0.01~0.12 m, 0.01~0.1m. Located in the southwestern part of the study area, called Bu Langhe town,the observation wells(403) is weak change basically stable, too, but by the impact of coal mining in 21 st Century, after 2007 year the change increases, even for moderate changes in medium changes type.(3)Dynamic change of groundwater in the study area is mainly influenced by natural factors and human’s activity factors, natural factors are mainly precipitation and Landform and topography, Landform and topography determines the groundwater depth, precipitation makes the groundwater level fluctuation cycles. As the study area belongs to the energy industry base, so the main human’s activity factors is the mining of coal and other energy, its changed aquifer water conditions, and lead to abnormal changes of the groundwater table. According to the basic situation of yulin city and groundwater resources change, on the premise of protection of groundwater resources, put forward reasonable Suggestions to groundwater resources sustainable development as the goal, with the coal resources of energy such as coal, natural gas, petroleum mining.