Identification Of Key Areas For Ecological Restoration In National Land Space Based On Ecological Security Patterns

With changes in land use and the expansion of human production activities,the structure and function of ecosystems have gradually been damaged,resulting in a series of ecological problems such as reduced biodiversity,increased soil and water erosion and degradation of environmental quality,hindering the sustainable and healthy development of society and the economy.To cope with the increasingly serious ecological and environmental problems,the Chinese government has given prominence to the construction of ecological civilisation,made the construction of an ecological security pattern a strategic goal,and actively promoted the systematic management of mountains,water,forests,fields,lakes and grasses to ensure the healthy and stable development of the ecosystem.The Gansu section of the Bailong River Basin is an important water source and ecological barrier in the upper reaches of the Yangtze River,but the fragmented terrain,severe soil erosion and geological hazards in the area have brought ecological and environmental problems to the fore.Therefore,it is important to conduct timely research on the ecological security pattern of the river basin and carry out ecological restoration of the national land space to ensure ecological security of the river basin,maintain ecological stability and promote sustainable and high-quality development.In this paper,the DEM,land use type,vegetation cover,slope,distance from rivers,rainfall,temperature,MODIS images and soil texture data of the Gansu section of the Bailong River basin are used as the basis to identify ecological source sites by comprehensively analysing the importance of ecosystem service functions and the sensitivity of soil erosion in the study area,determining the weights of multiple indicators through hierarchical analysis,and constructing a composite ecological resistance surface in the study area.The circuit theory model was used to identify ecological corridors,ecological "pinch points" and ecological barriers,and to construct an ecological security pattern for the study area.Finally,the results of the ecological safety pattern were combined with the actual ecological endowment of the watershed to identify priority areas for ecological protection and restoration,which were divided into conservation areas,restoration areas and enhancement areas,and the corresponding protection and restoration recommendations were made.The main research findings are as follows:(1)A total of 84 ecological source sites with a total area of 3642.28km2 were identified in the Gansu section of the Bailong River Basin,mainly in the southeastern part of Wen County,the central part of Diebu County and the southern part of Wudu District,with a relatively uneven spatial distribution;a total of 200 ecological corridors with a total length of about 1753.07 km were identified,with the exception of Tanchang County,where the distribution of ecological corridors is relatively small,and the rest of the counties are relatively evenly distributed.The ecological source sites and ecological corridors in the study area are mainly woodlands,grasslands,arable lands and waters with strong ecological service functions and rich biodiversity.(2)A total of 49 ecological "pinch points" have been identified in the Gansu section of the Bailong River Basin,with a total area of 8.18km2,It is mainly located in areas with low ecological resistance values,with the exception of Tanchang County,where the distribution is relatively small,the remaining counties and districts are relatively evenly distributed and located within the scope of ecological corridors.The current land type distribution in the region is mainly forest land,grassland,cultivated land,and water areas with rich ecological service functions;a total of 27 ecological obstacle points were identified,with a total area of 5.65km2,they are located at the gap between adjacent ecological sources.Except for Tanchang County,where there are no ecological obstacles,the distribution of other counties is relatively uniform.The current land type distribution in the region only includes forest land,grassland,cultivated land,and water.(3)Based on the ecological security pattern of the Gansu section of the Bailong River Basin and the actual ecological endowment of the study area,the key areas identified for protection and restoration were divided into ecological conservation areas,ecological restoration areas and ecological enhancement areas.The ecological conservation zone covers an area of 4073.10km2,with high habitat quality,and should focus on the protection and maintenance of this area,abiding by the principle of natural restoration,prohibiting all kinds of development and construction activities,and relying on water resources and biological resources to enhance the landscape richness,achieve natural restoration of community structure and form a sustainable ecological cycle.The ecological restoration zone,with an area of 1625.06km2,is the most important area in need of restoration and improvement,and should focus on ecological restoration,supplemented by human intervention to control environmental pollution,improve habitat quality,and build biological channels to enhance ecological connectivity and ensure smooth species migration.The ecological improvement area covers an area of 2139.52km2,it is an important ecological barrier for the stable development of the research area.It is necessary to combine the ecological endowment of the research area,fully utilize regional ecological resources,develop environmental protection industries such as characteristic agriculture and ecotourism,build new ecological towns,focus on improving the quality of the ecological environment,and explore green spaces.