Land Ecosystem Health Evaluation And Key Area Identification In Xi’an City

Promoting the healthy and coordinated development of living organisms and the natural environment is an important foundation for achieving harmonious coexistence and high-quality development between humans and nature.With the rapid advancement of population and land urbanization,the land ecosystem has been negatively affected by human unreasonable activities,resulting in a gradual decline in its quality and carrying capacity.The lack of structural and functional stability and resilience is becoming increasingly evident.Analyzing the spatiotemporal characteristics of land ecosystem health based on existing research results,and diagnosing degraded areas based on the differences in key factors of regional land ecology,identifying key areas for restoration and governance,is an important path for carrying out ecological restoration and ensuring national security.Therefore,conducting regional land ecosystem health assessment is a hot topic in the research of sustainable land use and ecological civilization construction.On the basis of reviewing relevant research at home and abroad,combined with the current situation of land ecology in Xi ’an,this paper selects 60 evaluation indexes from six aspects of natural disturbance,human disturbance,system vulnerability,structural integrity,productivity and resilience to build Xi ’an land ecosystem health evaluation system.At the same time,the 1000m×1000m grid is taken as the research unit.The entropy weight method and comprehensive evaluation method were used to calculate the land ecosystem health index of Xi ’an from 2010 to 2020.On this basis,Moran’s I index and hot spot analysis were used to describe the temporal and spatial characteristics of land ecosystem health.In addition,on the basis of the above evaluation results,the land ecosystem degradation areas in Xi ’an were comprehensively diagnosed by constructing ecological security pattern and analyzing the ecosystem service value difference,vegetation coverage and landscape disturbance change,and the key areas and types of restoration and governance were further identified.The main conclusions are as follows:(1)The overall health status of the land ecosystem in Xi’an City showed a continuous improvement trend from 2010 to 2020,with a slow increase from 2010 to2015 and a linear increase from 2015 to 2020.At the same time,the spatiotemporal differentiation characteristics of the land ecosystem in Xi’an City were significant during the three periods of 2010,2015,and 2020.Among them,the northern foot of the Qinling Mountains is the area with good health status of the land ecosystem in Xi’an City,while the health status of the land ecosystem in the low hills of the Lishan Mountains and the Wei River Basin still needs to be treated and protected according to the situation.(2)From the perspective of each subsystem of the PSR model,the health index of the pressure subsystem,the state subsystem,and the response subsystem generally shows an upward trend.The spatiotemporal differentiation of the health status of the land ecosystem in the pressure subsystem is mainly characterized by differences in the north and advantages in the south.The spatiotemporal differentiation of the state and response subsystem is closely related to socio-economic development,so its spatiotemporal differentiation is mainly characterized by the development of administrative divisions;Overall,the health status of the land ecosystem at the pressure,state,and response levels in Xi’an is continuously improving,but it still cannot be separated from the policy support of the local government and the rational allocation of resources.(3)Based on the comprehensive evaluation results of the health status of the land ecosystem in Xi’an,combined with the difference in land use change value,landscape disturbance index,and forest cover change,a land ecosystem security pattern in Xi’an was constructed.At the same time,a comprehensive equal weight method was used to identify the degraded areas of the land ecosystem in Xi’an;From the results,it can be seen that the prominent problem in the degradation of land ecosystems in Xi’an is the fragility of urban and agricultural ecosystems,and the insufficient stability of land ecosystem structure and function.The land ecosystems in the Weihe River Basin and the low hills of Lishan Mountain have shown significant degradation,and effective governance and restoration measures are urgently needed.However,the forest ecosystem in the northern foot of the Qinling Mountains has been well protected.(4)Based on the above comprehensive evaluation results and diagnosis of the health status of land ecosystems in Xi’an City,the key areas and types of ecosystem degradation such as farmland,water,and forest were identified for their restoration and governance,and improvement suggestions were proposed based on the ecological problems faced by the areas.