Red Line Delimitation Of County Ecological Protection Based On Super Learner

In recent years,China’s economy has developed rapidly,the scale of urban areas has gradually expanded,people’s income has gradually increased,and living conditions have been improving day by day.But the rapid economic development has also had a negative impact,ecological land is decreasing,resources and environment are destroyed,restricting people’s desire for healthy life and social sustainable development.In order to improve the ecological environment and ensure the sustainable development of economy and society,the Eighteenth National Congress of the Communist Party of China proposed to vigorously promote the construction of ecological civilization and optimize the pattern of land and space development.The Third Plenary Session of the Eighteenth Central Committee proposed to delimit the red line of ecological protection and protect the ecological environment.Which land use can be classified as the red line of ecological protection and how to delimit the red line of ecological protection have become an important scientific issue that needs to be studied urgently in the construction of ecological civilization.It is of great significance to scientifically delimit the red line of ecological protection and the Sansheng space,to promote the harmonious coexistence between human beings and the natural environment and to promote the sustainable development of social economy.In this study,Longkou City,Shandong Province,was taken as the research area,and an ecological evaluation index system including the importance of ecological function and ecological sensitivity was constructed.The importance of ecological function and ecological sensitivity were evaluated by comprehensive evaluation of multi-factors and spatial analysis of GIS.The red line of ecological protection was initially delineated.On this basis,based on Super Learner machine learning model,no decision was made.With the goal of protection,we should optimize the red line of ecological protection.The main contents and results of the study are as follows:(1)Assessment of the Importance of Ecological FunctionConsidering the natural conditions and environment of Longkou City,three indexes of water conservation,soil and water conservation and habitat maintenance were selected to evaluate the ecological importance function.Water conservation function is calculated by water decomposition model method,soil and water loss equation method,and habitat quality maintenance function is calculated by In VEST model method.Three kinds of ecological function importance are calculated and graded.Based on weight superposition,the important results of ecological function in Longkou City are obtained.The results show that Longkou City has good ecological function,which can be divided into five levels: extremely important,important,medium important,generally important and unimportant.The area with extremely important ecological function is 17.39 square kilometers,accounting for 1.94% of Longkou’s area,mainly distributed in Shiliang,Qijia and Xiadingjia towns.The main areas with important ecological functions are Wangwu Reservoir,Xiadingjiazhen West,Longgang Street West and North,Zhuyuguan Town,with an area of 31.41 square kilometers.The rest of the region is in general ecological condition.(2)Assessment of ecological sensitivityThree ecological sensitive functions,soil erosion,desertification and coastline erosion,were selected to evaluate.After grading and assigning according to the evaluation factors,the importance of three types of ecological functions was calculated,and the results of ecological sensitivity of Longkou City were obtained by overlapping the weights.The results show that the ecological sensitivity of Longkou City can be divided into five levels: extremely sensitive,highly sensitive,moderately sensitive,slightly sensitive and insensitive.The area of ecologically sensitive area is 0,and the area of ecologically highly sensitive area is 14.07 square kilometers.The main influencing factor is seawater erosion,which is 1.56% of the area of Longkou City,located on the west coast of Longkou City.The moderately sensitive areas are located in the north of Longkou City,with an area of 5.37 square kilometers,accounting for 0.6% of the county area.The most ecologically slightly sensitive areas are located in Longkou City.The rest are ecologically insensitive areas with an area of 18.40 square kilometers,2.05% of Longkou’s area.(3)Delimitation of red line for ecological protection based on Super LearnerBased on the evaluation of the importance of ecological function and the evaluation of ecological sensitivity,the prediction probability is taken as the target value and the six factors of ecological importance and sensitivity are taken as independent variables.Based on Super Learner model,six algorithms,random forest,decision tree,neural network,generalized additive model,stepwise regression and generalized linearity,are selected to predict the red line probability of ecological protection by 10 fold cross-validation.Rate,set different targets such as prediction probability,area proportion and total area,and delineate the red line of ecological protection.Considering the social and economic characteristics of Longkou City,the red line area of ecological protection is finally delineated with a total area of 20%.The results showed that the red line area of ecological protection was 182.85 square kilometers,accounting for 20.29% of the total area of Longkou City.It mainly distributes in the mountainous and hilly areas of Southeast China,and concentrates on continuous distribution.Compared with the traditional delineation method,the area of ecological protection red line increased by 50.16 square kilometers.The three cities with the largest area of ecological protection red line are Shiliang Town,Xiadingjia Town and Dongjiang Street,covering 41.86 square kilometers,32.82 square kilometers and 20.65 square kilometers respectively.The layout of eco-protected areas is more reasonable,which is conducive to maintaining the stability and integrity of its ecosystem,maintaining its good ecological environment,continuously providing ecosystem services for mankind,and promoting the harmonious development of man and nature.Selecting the evaluation index system of ecological function importance and ecological sensitivity,using Super Learner model to optimize the preliminary delimitation results,taking into account the basic situation of Longkou City,and finally delineating the red line of ecological protection.To make up for the shortcomings of previous single delineation method,rough quantification of ecological indicators,unreasonable prediction of future ecological environment,improve the scientificity of ecological protection red line division,provide flexibility for decision-making and management,provide scientific basis for future dynamic changes of ecological protection areas,and improve the efficiency of division.