Assessment On Ecological Risk Of Land Remediation

Land remediation is not only an important method to improve land quality and promote land intensification but also an effective method to implement balance between occupation and compensation of farmland.But large-scale land remediation may have an impact on the local ecological environment.At present,ecological land management is widely advocated,and ecological risk assessment is the basis of ecological land remediation.Therefore,this paper takes the land remediation planning of Wushan county as the research object to evaluate the possible ecological risks in the land remediation,Research results showed that:(1)The risk source of land remediation plan in Wushan county was four types of remediation projects,by calculating the different risk source relative risk value,found that the highest risk is farmland remediation,followed by is undeveloped and suitable for farm,and then the rural construction land control,the smallest risk is land reclamation.(2)Through the analysis of the implementation process of this remediation plan,six land types were selected as the habitat of this study according to the objects affected by land remediation activities.By calculating the relative risk value of different habitats,it is found that the risk of cultivated land is the highest,followed by the residential area,undeveloped land,woodland and mining land,and the risk value of grassland is the lowest.(3)Combining potential ecological risk of land reclamation planning analysis with the choice of habitat types,screening ecosystem function damage of ecosystem that creature live caused by the activity in the renovation plan,ultimately selecteing four types of ecological receptors,through the calculation of relative risk value of different ecological end receptors,found that the value of highest risk is soil quality,followed by landscape pattern,then the water environment,the smallest risk is biodiversity.(4)The relative ecological risk values of 15 risk zones in Wushan county are calculated.According to Arc Gis natural breakpoint method,it is divided into five grades.Value between 0.11 with 0.44 is the lower area with an area of 21792.54hm2,accounting for 7.66% of the total area of the county.Value between 1.56 with 2.35 is low-risk areas with an area of 82545.51 hm2,accounting for 41.35% of the total area of the county.Value between 4.30 with 5.68 is medium risk areas with an area of 44306.99 hm2,accounting for 22.2% of the total area of the county.Value between 14.44 with 19.82 is higher risk areas with an area of 35691.82 hm2,accounting for 17.88% of the total area of the county.Value is 29.77 is a high-risk area with an area of 15281.95 hm2,accounting for 7.66% of the total area of the county.The high risk area will improve the quality of cultivated land,the agricultural production condition and land ecological environment.The higher risk area actively implements the slope land reform to the terrace project,strengthens earth ditch and earth slope,s comprehensive management,advances the protection of farmland and the construction of ecological environment.The middle risk area mainly focuses on improving the network of drainage and irrigation channels,constructing farmland that still have a good harvest while drought and waterlogging,and focusing on land consolidation that construct road.The lower risk area is mainly to expand the cultivated land area,establish the high-yield and stable field,strengthen greening,and control the river wall.Low risk area is not suitable for the implementation of the land reclamation project,the region should strive to self-sufficiency,promote the comprehensive development of agriculture,forestry,animal product industry.The part of the hilly area which not suitable for farming can consider returning farmland to forest land,And offer advice for the implementation of the plan and the project arrangement.