Benefit Analysis Of Ecological Restoration Measures In Abandoned Mining Area,Altay Mountains

Recovery of mining area is one of the focuses of sustainable utilization of land resources in twenty-first Century.This paper takes the damaged mining area of the Reservation of Two River in Altai Mountain as research area.In the process of gold mining,destroyed the topography and physiognomy of the mining area,the soil particle finer completely disappeared,the surface is covered with gravel,vegetation disappeared.According to the local conditions,from four aspects of topography,soil,vegetation and soil,Set up 11 measures,77 superimposed measures,Five indexes of soil rock ratio,vegetation coverage,species diversity,vegetation similarity index and aboveground biomass were selected,Monitoring of plots,The ecological restoration effects of different restoration measures on mining area are discussed,Considering the cost of governance,Finally,2 kinds of recovery measures suitable for large-scale extension were screened out.The main results were as follows:(1)After the gold mining activities,serious damage to the local natural landscape,Formed a very uncoordinated appearance with the surrounding environment,Mainly in: 90% ore section of abandoned land topography,increase the vertical drop increased from 1m to 20-30m;the content of soil decreased by 98% compared with the original grassland,soil erosion has been completely lost;the average height of grass decreased 30-50 cm,grass cover decreased 20%-40%,biomass and species diversity decreased dramatically,almost 0.In the face of a wide range of damage,the severity of the status quo,if only by the ability of self-regulation of the ecosystem,even after hundreds of years may not be able to achieve the restoration of ecological structure and function.(2)From the point of soil content(soil-stone ratios),The soil-stone ratios is 40 times more than that of abandoned mining area,River flooding measures to restore effective;From the angle of comprehensive recovery of vegetation,vegetation coverage,species diversity index,similarity index and aboveground biomass of four indicators,ecological benefit calculation of mining area recovery,Cover soil measures had the best effect on vegetation restoration,reaching 2.4.(3)After considering the ecological and economic benefits,different restoration measures are compared.Take river flooding,artificial resow governance measures,low cost,suitable for large scale promotion.After restoration measures,the restoration effect of soil and surface vegetation is more and more obvious with the increase of restoration period.Taking the cover soil measure as an example,if the ratio of soil to rock,aboveground biomass and community similarity of abandoned mining area will be restored to the original grassland level,also needs 10.7 years,14.8 years and 30 years,if you want to achieve functional recovery even longer.(4)Taking single restoration measures can improve the ecological benefits of abandoned mining area,But the recovery cycle is long,and the superposition measures can more effectively restore the ecological benefits of abandoned mining areas.In the case of low cost,it is recommended to take the "Roughly leveling+ Spray mud 3 times " measure.In the condition of sufficient funds,take the "Precision leveling+ Cover foreign soil 14 cm + Plant Ribes nigrum + Resow" measures.After adding mud injection measures alone,The ecological benefit normalization index increased by 0.476,while the normalization index of governance cost increased by only 0.041,The ratio of the two,that is,the ecological benefit per unit cost is 11.55.It shows that this measure is very effective and more reasonable for recovering abandoned gold mining area.