| The development of open coal mine seriously damages the ecological environment of the mining area.As a key place for ecological restoration of open coal mine,the ecological environment of dump is still fragile after reclamation.Its interference affects the stability of ecosystem reconstruction,directly relates to the success or failure of ecological restoration of the mining area.It is particularly important to the evaluation of the disturbance in the long-term restoration process.It has certain practical significance of the monitoring and restoration of the ecological environment of the reclaimed land.Based on the MODIS Global Disturbance Index and the combination of surface temperature and enhanced vegetation index,this paper constructs the Dump Reclamation Disturbance Index(DRDI)based on Landsat image,and calculates the28 year disturbance index and its spatial-temporal differentiation characteristics of the dump in Antaibao open coal mine,Pingshuo,Shanxi Province.According to the dynamic characteristics of the interference index time series,the interference types are divided by pixel.Through selecting,statistical analyzing and geographical detecting the terrain,soil,vegetation and other factors,its impact on the interference types is explored.The main results and conclusions are as follows:(1)DRDI can be used to evaluate the time limit of ecosystem stability of reclamation dump and effectively identify the spatial scope and severity of vegetation degradation in the disturbed ecosystem.DRDI can be used to evaluate the reclamation effect of waste dump,which will provide reference for optimizing the reclamation mode and improving the reclamation efficiency.In the early stage of reclamation,the area with strong disturbance shows strong spatial aggregation characteristics.The average time for vegetation structure and function to recover to the natural level is about 10 years,and the disturbed area of a single spoil bank can be reduced to between 1.32% and 17.76%.Four spoil bank in Antaibao open pit coal mine of Pingshuo show typical differences in stability time limit and interference distribution characteristics,which are driven by waste dump mode,reclamation direction,time limit,landform and other factors.(2)Among the terrain factors,when the overall elevation is relatively low,the interference tends to increase with the increase of elevation,and increases with the increase of slope,leading to the increase of interference.When the slope is large andthe slope direction is sunny,the interference type is easy to show as wave interference type.Among the soil factors,the higher the pH is,the stronger the disturbance will be;when the organic carbon and total nitrogen are restored to the original geomorphic level,the more stable the disturbance type will be with the increase of the content;when the effective phosphorus content is lower,the impact on the wave degradation type will be more significant.Among the vegetation factors,the anti-interference ability of different reclamation modes is: arbor shrub grass > shrub grass > arbor grass > grassland > cultivated land in turn;With the increase of reclamation time,the proportion of stable restoration and restoration degradation gradually increases,the proportion of early wave restoration gradually decreases,and the wave interference type is basically not affected by reclamation time.(3)The Geodetector indicates that the order of spatial differentiation interpretation power of interference type is: reclamation time > pH > elevation > total nitrogen > organic carbon > slope direction > slope > available phosphorus >reclamation mode,and both of them show nonlinear enhancement.The combination of reclamation time and elevation can explain 46.41% of the interference types with the strongest spatial differentiation,and the interaction between reclamation time and other influencing factors has stronger interpretation power. |
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