Research On Identification And Strategy Of Key Areas Of Ecological Protection And Restoration Based On Circuit Theory

Ecosystem preservation and restoration of Mountain-River-Forest-Farmland-Lake Grass System is very important for national ecological security.Xixia belongs to Danjiang River System in Hanjiang District of the Yangtze River Basin.Maintaining the water conservation capacity of Xixia County is of great significance for the protection of Danjiang Reservoir.At present,Xixia County is mainly faced with ecological and environmental problems caused by industrial and mining development,such as soil erosion,geological disasters and so on.Based on the ecological background of Xixia County,how to build the basic ecological security pattern and identify the key areas of ecological protection and restoration is an important means to improve the regional ecological environment.Based on Xixia County ecological land,through the construction of multi index evaluation system to identify different levels of importance of ecological space,and then comprehensive screening to get the ecological source,using the minimum cumulative resistance model to build the basic ecological security pattern,and using the circuit theory to extract the ecological corridor,ecological pinch point and obstacle point,identify the key areas of land space ecological protection and restoration,Finally,the implementation strategies of ecological protection and restoration are put forward from multiple perspectives.The results are as follows:(1)The distribution structure of ecological spatial importance showed that the bottom limit ecological space area was 91673.36hm~2,accounting for 29.61%of the ecological land area;The intensive ecological space area was 73521.67hm~2,accounting for 23.75%of the total ecological land area,and the buffer ecological space area was 111274.1hm~2,accounting for 35.94%of the total ecological land area;The general ecological space area is the smallest,which is 33099.31hm~2,accounting for 10.69%of the total ecological land area.(2)The ecological resistance value of most areas in Xixia County is maintained at a low level,because nearly 90%of the total land area in Xixia County is ecological land,the landscape connectivity is high,and the resistance of species migration is small as a whole.The land use types in this area are mainly woodland,garden,grassland and cultivated land,the habitat quality is good,and the disturbance of human activities is small,It is conducive to the migration of species.The areas with high resistance value are mainly distributed in the county center and Township Center,and the land use type is mainly construction land.The frequent human activities and the dense distribution of rivers in this area play a negative role in species migration and material information energy exchange to a certain extent.(3)A total of 42 ecological corridors were extracted in Xixia County,and the overall distribution of corridors showed a pattern of"one horizontal and three vertical".There are 25 key ecological corridors,accounting for 59.52%of the total number,and the total length is 123.07 km,accounting for 38.86%of the total length.They are scattered among the ecological source plates in Xixia County.There are 16 ecological"pinch points",which are the areas to be repaired,covering an area of 1843.51hm2,mainly distributed in zhaigen Township,MIPING Town,DINGHE town and Shuanglong town.There are 40 ecological barriers in Xixia County,with a total area of 8425.68hm2,mainly distributed in the middle of the county,and a small amount in the west of the county.Based on the identification results and distribution of ecological source,important ecological"pinch points"and obstacle points,the ecological protection and restoration strategies were discussed from the aspects of classification and hierarchical management,core source protection and key elements restoration.