Study On Ecological Security Pattern Construction In Tang County Based On Land Ecological Risk Assessment

A sound ecological environment is the most universal benefit to people’s lives.In today’s rapidly developing society,land is increasingly used by human beings.The disturbance of human activities may lead to some irreversible ecological problems,and land use is facing a serious ecological risk situation,therefore,revealing the risk pattern of regional land use and constructing the ecological security pattern satisfying the sustainable growth of regional economy have become one of the hot issues studied by natural resource management departments and academic circles,which is of great significance to the construction of regional ecological security barrier.The high quality ecological pattern is the key to the high quality development of county economy.Based on risk theory,this study constructed an ecological risk assessment index system for land at the county scale from three dimensions:risk source,ecological quality and ecological fragility.Taking Tang County,a typical hilly area,as an example,this study analyzed the land use change and ecological risk in Tang County in 2000,2007 and 2018.On the basis of the risk assessment results,combined with the minimum cumulative resistance model and circuit theory,the ecological security protection factors at the county level were extracted comprehensively,so as to construct a systematic and complete ecological security pattern in Tang County,and put forward some suggestions on the optimization of ecological security pattern.The main conclusions are as follows:(1)The land cover of Tang County changed greatly in 18 years,the influence of regional human social and economic activities on the natural environment system showed a weakening trend.During the study period,the cultivated land,woodland and unused land area changed greatly.Among them,the area of cultivated land and woodland increased significantly,the unused land area decreased significantly.From the perspective of spatial distribution,the central and northern areas of Tang County changed obviously.From 2000 to 2018,a variety of interconversion phenomena occurred among different land use types in Tang County,among which the unused land conversion area was the largest.In the past 18 years,the dynamic attitude of comprehensive land use in Tang County has shown a very obvious decreasing trend,which indicates that the natural environment in Tang County is less affected by various social and economic activities from human beings..(2)During the study period,the ecological risk of land in the study area was significantly different,and the overall spatial pattern was lower in the north and higher in the south.this study constructed the ecological risk assessment index system of land in Tang County from three aspects:risk source index,ecological quality index and ecological fragility index to evaluate the ecological risk of Tang County,the average value of ecological risk of land in Tang County in 2000,2007 and 2018 was 0.22,0.26 and 0.25,respectively,showing a trend of first increasing and then decreasing.(3)In this study,the ecological pattern of Tang County was constructed based on the minimum cumulative resistance model and circuit theory.Based on the ecosystem services of high forest land,grassland and waters as alternative ecological source,ecological risk lower area is extracted as the ecological source,combined with the minimum cumulative resistance model and circuit theory to construct comprehensive resistance,and identify the various elements in the ecological security pattern of Tang County,including ecological corridors,ecological barriers and ecological pinch points,there were 21 ecological sources,covering an area of 9772.99hm2,54 ecological corridors and 20 ecological pinpoints were identified,so as to construct a complete ecological security pattern in Tang County.On this basis,some suggestions and measures for the optimization of ecological security pattern are put forward.This study has a certain reference value for the formulation of ecological protection planning in Tang County,is conducive to the improvement of ecological environment quality in Tang County,and also provides methods for reference for related regional research.