Evaluation Of Land Ecological Restoration In Arid And Semi-arid Mining Areas

The report of the 20 th National Congress of the Communist Party of China clearly pointed out that how to improve the effect of ecological restoration has become an urgent problem to be solved in the process of ecological civilization construction.Shenfu Dongsheng mining area plays an important role in resource and energy rationing as an important development zone of energy resources.Shendong Mining area is located in the Mu Us Sandy Land and the Loess Plateau transition zone.It belongs to an area where natural ecological factors such as heat,moisture and light change rapidly,and its ecosystem is extremely fragile.It is also an area where human activities are intense.Monitoring and evaluating the change of ecological restoration effect in mining areas is an important link to ensure the regional ecological environment.The significance of this work is to provide theoretical basis for land ecological restoration in similar mining reclamation areas.Taking Shendong mining area as the research area,this paper summarizes the research progress at home and abroad on ecological restoration and evaluation of restoration effect by sorting out relevant data.Using software such as Arc GIS and In VEST,Landsat and Modis remote sensing images from 2006,2012,2016,2019 and 2021 and measured soil data from different periods in the study area were used.The change of vegetation index,geomorphic index,soil index and landscape index in the well mining area from 2006 to 2021 was analyzed.Two first-level indexes and 15second-level indexes were selected to construct an evaluation system of ecological restoration effect.The ecological restoration effect in the mining area was evaluated by combining with the analytic hierarchy process,and the obstacle degree model was used to analyze the factors affecting the ecological restoration effect in the Shendong mining area.Put forward scientific ecological restoration suggestions.The results show that:The index of land ecological restoration showed a good trend over time.From 2006 to 2021,the vegetation index increased gradually,and the spatial distribution was high in the middle and low in the east and west.The net primary productivity of vegetation in the study area increased from 2006 to2019,and decreased slightly in 2021.The mean vegetation coverage increased from 0.43 in 2006 to 0.50 in 2021.Soil erosion intensity decreased first and then increased from 2006 to 2021.The soil moisture value showed a continuous increase,and the concentration area of high value was more.The surface temperature decreased first and then increased.Soil carbon storage fluctuated and increased during the 15 years,and the low value was mainly concentrated in the southwest of the study area.The land use type in the north of Shendong Mining area has the most obvious change,and the land for industrial and mining storage is the most obvious change.Grassland had the greatest impact on landscape pattern.The landscape shape index(LSI)and Shannon diversity index(SHDI)showed a downward trend during 2006-2016,while the landscape shape index(LSI)and dispersion index(SPLIT)showed a slight upward trend during 2016-2021.As a whole,the patches in the study area tend to be irregular due to the construction of some infrastructure.The effect of land ecological restoration gradually improved over time.The evaluation score of ecological restoration effectiveness increased from0.4486 in 2006 to 0.4714 in 2021,and the area of ecological restoration effectiveness grade I increased gradually,reaching 304.92km2 in 2021,accounting for 2.49% of the total area.The research evaluation value showed a state distribution of low east-west and high in the middle.The central part has a good foundation of ecological restoration effect and it is still getting better in recent years,while the southeast part is the area where the ecological restoration effect is gradually improving.The feature of obstacle degree factor analysis was obvious,and each factor had significant influence on the repair effect.The top three indexes affecting the ecological restoration in the study area are soil carbon storage(C9),soil moisture(C8)and FVC(C3).The influence of soil carbon storage,soil moisture and vegetation coverage on the ecological restoration in the study area cannot be ignored.It is suggested that in the future ecological restoration process,we should improve the multi-subject participation mechanism of mine ecological restoration,close to nature,zoning planning,improve the restoration technology,realize the dual protection of coal and water,give ecological priority,and pay attention to the ecological "carbon sink" ability.