Effects Of Coal Mining Subsidence On Soil And Vegetation And Protection Management

Surface cracks and subsidence caused by coal mining have changed the initial conditions of soil and vegetation growth in the mining area and surrounding areas,and a series of ecological environment destruction problems have become important limiting factors of sustainable development in the mining area.Therefore,aiming at the mining subsidence area,it is particularly important to actively explore various ways and measures to control the impact of the existing subsidence on the environment and the prevention and control of the new subsidence.Taking the soil and vegetation in Shendong mining area as the research object,through field investigation and laboratory experiment,the changes of soil properties and vegetation species distribution in the initial period,active period and decline period of mining subsidence were analyzed.Based on the data of Sentinel-2 and CLCD land cover products,the spatial and temporal changes of vegetation coverage and the relationship between land type change and subsidence were explored by using photography,binary pixel model,unitary linear regression method and transfer matrix.In order to grasp the influence of mining subsidence on soil and surface vegetation;On the basis of the above research,the existing problems in the protection and management of the subsidence area in Shendong mining area were explored,and the effective measures to improve soil quality and vegetation restoration were proposed.The main conclusions are as follows:(1)The soil sand content in the study area was more than 84%.In the initial stage of subsidence and early active stage,soil coarse-grained was aggravated,nutrient content decreased,vegetation degradation was significant,plant species gradually enriched,and vegetation coverage was high;In the later stage of active subsidence,the soil quality continued to decline,and perennial herbs were gradually replaced by one or two year herbs,resulting in poor plant growth and reduced coverage.During the period of subsidence and decline,the soil nitrogen and phosphorus content gradually approached to the level of non-subsidence area,and vegetation also recovered to different degrees.(2)From 2000 to 2019,the change of land type in the study area was mainly among cultivated land,grassland and unused land.Under subsidence disturbance and human intervention,FVC of Shendong Mining Area showed a slow decreasing trend from 2017 to 2021 except 2018,with an average change rate of 0.01/a.The vegetation coverage changes differently in different subsidence stages and site conditions.(3)There are still problems in soil reconstruction,such as fissure filling,soil fertilizer improvement,soil pollution,plant species selection and vegetation management in the mining area.It is suggested that on the basis of the existing management and protection measures,The cracks filling materials,soil fertilization,acid and alkaline improvement and heavy metal pollution control,subsidence edge blocking,plant species selection,vegetation management and protection,soil nutrients and vegetation growth monitoring technology in subsidence area were improved.In order to shorten the recovery period of subsidence area and improve the ecological environment of mining area.