| Mining in the mining area will not only cause surface cracking and subsidence,but also cause changes in soil moisture in the coal mining subsidence area,thereby destroying soil productivity and causing water and soil erosion and other hazards.Taking the Shiping mining area in Luzhou City,Sichuan Province as the research area,based on data collection and field investigations,the sentinel No.1 data was used to monitor the deformation of the mining area,and the subsidence area of the mining area was extracted,and GNSS measured values were used for verification.Using Landsat8 data to carry out soil moisture inversion,compare the difference in moisture between subsidence areas and non-subsidence areas,and finally quantitatively evaluate the damage to the surface caused by mining disturbances,and explore the mechanism of the impact of mining activities on soil moisture.The main research contents and results in the article are as follows:(1)Quantitatively analyze the influence of season and time baseline on D-In SAR technology.Based on 12 sets of differential interference pairs with different time baselines and different seasons,the coherence is quantitatively analyzed,and the influence of time baseline and season on coherence is revealed.Studies have shown that when the seasons are spring and summer,the time baseline is 36 days,and the correlation is the lowest,0.286856 and 0.288054,respectively,when the vegetation is the most lush.When the season is winter and the time base is 12 days,the coherence of the differential interference pair is the highest,which is 0.562701.At this time,the interference of vegetation on the surface is lower than in other seasons.(2)Based on D-In SAR technology,extract the subsidence area of Shiping mining area from January 11,2020 to March 23,2020,and verify the deformation results with GNSS measured values.The results of monitoring points 3,5,6,and 8 are all that the deformation of In SAR monitoring is smaller than that of GNSS monitoring,and the trends are consistent.The maximum subsidence value of the subsidence area extracted by D-In SAR is 50 mm.(3)Analyze the changes in soil moisture from the time scale of the mining area.From 2013 to 2020,the TVDI value first increased and then decreased,and the soil moisture first decreased and then increased.The soil moisture content from high to low is spring,winter,autumn and summer.In summer,plants on the ground surface grow violently and need to absorb a lot of water,so soil moisture is the lowest.From the perspective of the subsidence area and the comparison area,in winter,the average change ratio of the TVDI between the subsidence area and the comparison area is-6.9% and-18.21%,indicating that the TVDI value of the subsidence area is less than the TVDI value of the comparison area,indicating the subsidence area The moisture is higher than the moisture in the contrast area.(4)Count the number of visible cracks and their shapes in the mining area.Use the probability integral method to calculate the mining impact of the 11519 work on the surface.The calculation result is compared with the land damage level table of the work face as a moderate damage.From ground fissures,slopes,and ground sinks,the paper discusses the analysis of the changes in the soil moisture mechanism caused by coal mining,and deeply analyzes the mechanism of the changes in surface water caused by coal mining. |
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