Evaluation And Pattern Optimization Of Watershed Ecological Security From The Perspective Of Human-land Coordination

Ecological security is to maintain the ecological environment of a region or country or even the world from threats,and it can provide ecological guarantee for the safety and sustainable development of the entire ecological economic system.Ecological security research should not only consider its pattern and process,but also consider the impact of landscape factors that reflect landscape structure and functional characteristics on ecological security.This study evaluated the spatio-temporal changes in the ecological security and landscape pattern in the middle and lower reaches of the Shule River Basin from 1987 to 2015.Determined the correlation coefficients of the two through correlation analysis and measurement methods,and discussed the key landscape pattern factors affecting ecological security based on land.Using type and landscape pattern factors,establish an ecological corridor network that includes ecological sources,ecological corridors,ecological nodes,and ecological resistance surfaces,explore the internal ecological processes that form an ecological security pattern,and achieve regional human-land coordination through optimization of the ecological security pattern In the course of research,the following conclusions were drawn:(1)The temporal and spatial differences of ecological security in the middle and lower reaches of the Shule River basin are significant: in terms of time,the overall score of the ecological security composite index from 1987 to 2015 is less than 0.5,which is between less safety and general safety,and shows periodic "U"-shaped fluctuation changes,and the change period is gradually shortened.High in space,by 1987,"Chinese and western,southeast low" transition to born in 1996 the pattern of "two high,intermediate low,back to the 2015" Chinese and western south high,east low "pattern,in the middle and lower reaches of shule river basin in fluctuation trend of ecological security is stable,risk control,improving ecological environment,improve to the coordinated development of contradiction;(2)Landscape pattern has obvious stage characteristics and spatial characteristics: in terms of time,from 1987 to 1996,landscape fragmentation was lower,landscape shape was more complex and irregular,landscape interaction was enhanced,and spatial pattern complexity increased;From 1996 to 2008,the dispersion between the same type of patches became larger,the landscape connectivity became worse,and the balance increased year by year.From 2008 to 2015,the distance between plaques of the same type became smaller,the distribution trend of agglomeration was enhanced,and the equilibrium still increased year by year.In space,the eastern region and southwest landscape less affected by human activities,landscape complexity is low,the landscape type is relatively single,while the central region and the northwest of human activities,the landscape patch shape more hasten is complex and irregular,strengthen mutual interference between the landscape types of sex,at the same time the balance of landscape increases;(3)The size,shape,quantity,type and spatial configuration of landscape have an important impact on ecological security.In a period when human activities have a weak impact,ecological security is mainly related to landscape index.With the increase of human activities,the shape,fragmentation and connectivity of landscape patches change greatly,resulting in changes in the structure and composition of the ecosystem,thus affecting ecological security.In 2015 eight of the 14 landscape index is closely related to the ecological security index,shows that with the increase of human activities,landscape shape,fragmentation,connectivity,etc have changed significantly,the landscape fragmentation degree,the types of landscape richness increased,landscape shape,the more complex,landscape interfere with each other,the more conducive to landscape balance increase,to help improve the quality of ecological security level;(4)This study conducted an ecological security evaluation from the perspective of human-land coordination.It was evaluated that the comprehensive indexes of ecological security in the middle and lower reaches of the Shule River Basin are low,and the regional ecological security pattern is optimized through the evaluation of natural high ecological service value.The ecological security index of the optimized ecological security pattern is improved significantly,and presents a harmonious and unified spatial pattern of small regions.Among them,47.83% of the towns and villages reach the safest level,and 39.13% of the towns and villages reach the safer level.The overall ecological security after optimization presents a pattern of "low in the east and high in the Midwest",and towns of all levels are relatively continuous and tend to be divided into small regions.The optimization of ecological security pattern improves the contradiction between man and land,accelerates the process of harmonious unity between man and nature,and provides reliable basis for the coordinated development of man and land in the region.