Study On The Carry Capacity Of Reclaimed Soil Environment In Datun Coal Mining Area

On the basis of systematic summary of related fields both at home and abroadabout ecological risk assessment, evaluation factors were selected according to thespecific situation of Datun mining area in this paper. Bearing capacity saturationindex and bearing capacity of risk index are adopted to evaluate the pollution extentof heavy metals, such as As、Cr、Zn、Pb、Cu、V、Co、Ni、Cd、Hg on lake mudfilled venue, deep-digging and shallow-filling venue, collapsing venue and originaltopography venue. Thus the soil environment bearing capacity of the three kinds ofvenue are evaluated; Soil fertility capacity index model was adopt to evaluate thecapacity of soil environment capacity, taking soil pH, organic matter, total nitrogen,total potassium, total phosphorus as fertility factors, using the method of principalcomponent analysis to get the weight of factors. This research can provide atheoretical basis for crop security on filled reclaimed soils; meanwhile providereference for filled reclamation and environment government in the mine subsidencearea.The major achievements and conclusions were obtained.(1) Carrying capacity of soil environment on lake mud filled venue, deep-diggingand shallow-filling venue, collapsing venue and original topography venue based onheavy metal pollution: Using the bearing capacity saturation method, the soilenvironmental capacities of four venues are basically the same with the rates between1and1.5, and with the grades of "medium". Using the bearing capacity of riskmethod, the soil environmental capacity rates of four venues are all less than150, thedegree are all “very high”. The carrying capacity of soil environment in the study areais in a good level. Both of the soil on the lake mud filled venue and the deep-diggingand shallow-filling venue are not polluted. The carrying capacity of soil environmentof the soil on the lake mud filled venue is the best, then the deep-digging andshallow-filling venue, original topography venue and collapsing venue in descendingorder.(2) Carrying capacity of soil environment on lake mud filled venue, deep-diggingand shallow-filling venue, collapsing venue and original topography venue based onsoil fertility: The comprehensive bearing index are0.3472,0.1823,0.1616and0.1704,and the levels are "moderate ","low","low" and "low". Lake mud filling reclamationis obviously better than other reclamation mode in the study area, which can provide some guidance for China’s utilization of lake mud filling reclamation. It can alsoprovide certain reference for soil environment bearing capacity of other kind ofartificial soil. It can provide some basis for the safety of mine filling reclamation soilfor planting crops. It is of great significance to the health, stable filling andsustainable utilization of reclaimed soil in mining area.(3) The soil in study area itself is poor, particularly in the absence of organicmatter, nitrogen and phosphorus. In order to increase agricultural production capacity,it is necessary to use biological, chemical and other measures to increase soil organicmatter and activity, and to improve soil physical and chemical properties.