Classification of disturbance types and influencing factors of reclamation dump in ecological fragile area

The reclamation effect of open-pit mining reclamation dumps plays a key role in rebuilding the stability of the ecosystem,and the reclamation effect is mostly analyzed through long-term monitoring of vegetation changes after reclamation. The open-pit mining dumps in ecologically fragile areas are susceptible to external disturbances,and the restoration stability presents large spatial differences. Taking the structural and functional characteristics of vegetation in the optimal state in the long-term series as the comparison standard,on the basis of the early construction of the Reclamation Dump Disturbance Index (DRDI),the disturbance types are further divided according to the dynamic characteristics of disturbance. And analyze natural and human-made factors that influence disturbance types. Four dumps of the Antaibao open coal mine in Pingshuo,Shanxi Province were selected as the study area. Their reclamation types,reclamation start times,and durations were different. Based on Landsat remote sensing images,calculate the DRDI of the research area from 1986 to 2017. The disturbance types were divided into continuous disturbance type,reclamation stable type,disturbance recovery type and reclamation degenerative type. From the aspects of terrain,soil conditions,and reclamation types,factors that may have an impact on the type of disturbance are selected for GeoDetector analysis. The research results show that the internal disturbance of the reclamation dump presents different dynamic characteristics after the occurrence of the disturbance,the type of disturbance has spatial heterogeneity. There is spatial aggregation of the same type in the spatial distribution of the same soil at a small scale,and the reclamation stable type and disturbance recovery type are the most obvious. The degree of influence of a single factor on the reclamation is followed by the type of reclamation,soil physicochemical properties and topography. At the same time,there is mutual influence among the factors,which affects the reclamation. The reclamation time has a greater impact on the disturbance type after the combined action of total nitrogen,elevation,available potassium and organic carbon,followed by the interaction between total nitrogen and pH. The interaction between factors is mainly nonlinear enhancement. But reclamation time and vegetation type affect reclamation through factors such as soil elements,and linear enhancement is the main method.The research results reveal the spatial heterogeneity of the disturbance and reclamation in the small-scale mining area and its relationship with the influencing factors. Provide suggestions and references for the reclamation of the mining area.