The Study On Early Warning And Regulation Of Eco-risk Of The Ecological Migration Resettlement Region

Ecological migration gives consideration to dual goals of poverty alleviation and ecological environment construction.the ecological environment in the emigration area should be relieved,and the stability of the ecological environment in the immigration settlement region should be ensured in the meanwhile.On the basis of Hongsibu District in 1995-2015 phase of remote sensing image data,based on the principle of landscape ecology,ecological carrying capacity and so forth,taking landscape disturbance and landscape vulnerability to construct ecological risk index,and the ArcGIS software was used for spatial Kriging interpolation.the analysis and evaluation of land use types,landscape structure and landscape ecological risk in the region were taken.The temporal and spatial variation characteristics of landscape ecological risk were analyzed and on this basis,using BP neural network model to predict and early warning the ecological risk in the future,the conclusions are as follows:(1)From 1995 to 2015,the landscape type structure changes significantly,grassland area continued to decline,which reducing 29744hm2 with a change rate of 18.76%,construction area is increasing,the total area increased by 4314hm2 with the change rate 79.78%,the forest land area increased 59.66%,water and farmland area were increased by 26.26%and 21.28%respectively,compared to the pre-immigration,sandy land and unused land area remained unchanged roughly.For the landscape pattern index,the overall number of landscape patches increased.During the whole study period the overall landscape fragmentation was increased and landscape isolation was of the rise,the dispersion degree becomes larger,and the landscape stability decrease,the landscape is faced with the risk of being further isolated and fragmented,and the landscape loss index also shows a rising trend.(2)The change of landscape structure leads to the difference of ecological risk in the study area.For the landscape type,the average ecological risk index of different landscape types was grassland>cultivated land>sandy land>unused land>forest land>water area>construction land.From the view of spatial variation,there are obvious spatial differences in the ecological risk in the Hongsibu District mainly with medium,higher and the highest risk grade area,the ecological risk spatial distribution showed a trend that the central and northern regions of Hongsibu town,Taiyangshan town,and Liuquan town,the southwest of Dahe town are higher,while the central and eastern Xinzhuangji town,Dahe town,and the southern Liuquan town are lower.From 1995-2015,the low and lower ecological risk area in Hongsibu District increased by 163.19km2 to 514.82km2,the proportion of the total land area increased from 5.92%to 18.68%;little change in area of medium risk areas,the proportion increased from 15.48%to 24.90%;higher and the highest risk region decreased from 2166.63km2 to 1554.31km2,which accounted for the proportion of the total land area reduced from 78.6%to 56.41%.(3)During the study period,the ecological risk early warning index of each year is between 0.1339-0.1847,although there is a certain gap,but the gap is not large.The Hongsibu town marks the highest point of the ecological risk early warning while decreasing in the vicinity.According to the prediction of BP neural network model,the early warning indexes of 2020 and 2025 were respectively 0.1847 and 0.1821,which is among the serious warning degree.During the whole study period,the ecological risk warning situation of the Hongsibu District showed the volatility change process of"mitigating-stabilizing-aggravating".From 2015 to 2025,the early warning index is on the rise,and the growth rate is gradually rising,the whole district still facing some threat.(4)Based on the comprehensive analysis of the status and development trend of ecological risk in Hongsibu District,and build on the static ecological risk evaluation in the past and the present as well as the results of dynamic ecological risk early warning to futher put forward the Hongsibu district ecological risk zoning management countermeasures and comprehensive governance model.