Research On Land Ecological Security Evaluation And Sustainable Utilization Countermeasures In The "Golden Triangle Of Shanxi,Shaanxi,Henan And Yellow River"

The land system is fundamental to human survival,reproduction and sustainable development,and it is an ecosystem that covers a variety of complex factors and contains many types of composite factors.With the approval of the State Council’s "Jin-Shan-Yu Yellow River Golden Triangle Regional Cooperation Plan" in 2014 and the first national level of ecological environment protection and ecological environment restoration "National Major Ecosystem Protection and Restoration Master Plan(2021-2035)" since the 19 th National Congress of the Communist Party of China in June 2021,it has a profound impact on the economic and social development of the study area.At the same time,the improvement of people ’ s living standards leads to obvious population growth,making limited land resources in short supply,as a scarce and limited land resources beyond its carrying range.At the same time,the development of human beings in the process of land development and utilization is larger,which makes the situation in some areas with fragile ecological environment more serious,and brings serious hidden dangers to the future work of soil and water conservation and land sustainable development.Therefore,it is urgent to accurately grasp the problems existing in the process of land use,promote the coordinated development of human-land system and realize the ecological security of land system.This paper takes the "Jin-Shaan-Yu Golden River Triangle" area as the research object,analyzes the natural and social profiles,the current situation of land use and its changes in the "Jin-Shaan-Yu Golden River Triangle" and each county and city(district).According to the sustainability of natural environment,coordination of economic development and adaptability of social development,18 indicators were selected to establish the evaluation index system of land ecological security in the study area,and the entropy weight method and comprehensive index method are used to determine the weight and evaluate the research.According to the rating criteria,the land ecological security of the counties(districts)in the study area is classified and the spatial pattern evolution is analyzed.Based on the analysis results,the influencing factors of ’ nature-economy-society ’ are analyzed.Finally,according to the research results and the actual situation of the study area,the sustainable utilization countermeasures of land resources are put forward.The conclusions are as follows :(1)Through the interpretation and analysis of remote sensing data from 2005 to 2018 in the counties and cities(districts)in the "Golden Triangle of Shanxi,Shaanxi,Henan and Yellow Rivers",In the past 14 years,due to the increasing demand for land,land reclamation and unused land development occurred in 46 counties(districts).The land area of 22counties(districts)increased and the land area of 24 counties(districts)decreased,resulting in a decrease of 237.73hm2 of land area in this area,and the proportion of the reduced area was less than 0.1% of the total area of the study area.In terms of changes in land use structure in the study area,the six types of land use were in a trend of change from 2005 to 2018.The area of construction land has always been increasing with the largest increase,and the proportion of changes in other land types is small.(2)The evolution of the spatial pattern of land use structure in the study area.From2005 to 2018,the proportion of cultivated land area accounted for 48%-49%,which is the largest land type among the 6 types of land use types;the forest land area changed little,accounting for 24%;the grassland area remained at 21 per cent by 2018,in addition to a slight decline in 2010;the area of construction land has increased the most,but its proportion has remained at 5% from 4% in 2005 to 2010-2018;The share of unused land in 2005-2018 was small and consistently less than 1 per cent%.At the spatial level,the counties with the highest and lowest proportion of cultivated land,forest land,grassland,water area and construction land in the land area of each county are Pucheng County and Xi County,Lushi County and Hejin City,Daning County and Quwo County,Hubin District and Ji County and Yima City and Ji County;the unused land area accounted for the smallest and the smallest,and the unused land area in Dali County accounted for the largest proportion of the counties.(3)In terms of land use structure transformation.During the 14 years from 2005 to2018 in the study area,among the six major land types,the land area decreased the most was cultivated land,and construction land,forest land,and water areas were the main destinations for the decrease in cultivated land.The forest area increased first and then decreased slightly,and the increased forest area mainly came from cultivated land.The grassland area is decreasing.The overall water area is in a downward trend.The area of construction land has been increasing in the past 14 years,and the cultivated land,forest land and water area flowed into the construction land the most,followed by grassland and unused land.The unused land showed a trend of first decrease and then increase from 2005 to 2018.(4)In terms of time series changes of land ecological security.From 2005 to 2018,the comprehensive index of land ecological security in the study area showed a gradual upward trend,and the change range was small;the changes of natural ecological subsystem,economic ecological subsystem and social ecological subsystem were all small.The comprehensive index of land ecological security was in an unsafe state(Ⅱ)from 2005 to 2010,and was in a critical state(Ⅲ)from 2015 to 2018.The natural ecological subsystem and the social ecological subsystem are the main factors affecting the land ecological security in the study area.The low level of land ecological security is still an urgent problem to be solved by relevant government departments.(5)In terms of changes in the spatial pattern of land ecological security.In 2005,counties and cities(districts)in extremely unsafe(I),unsafe(II)and critical state(III)in the study area accounted for 10.87%,80.43% and 8.70% respectively.By 2018,the safety evaluation level of the comprehensive index of land ecological security in the study area was unsafe(II)and critical state(III),accounting for 23.91 % and 76.09 %,respectively.The evolution of the critical state(III)level of the comprehensive index of land ecological security in the study area was sporadic distribution in Hejin City,Houma City,Huazhou District,and Yima City in 2005.By 2018,the overall trend from northeast to southwest was better than that of northwest and southeast.(6)In this paper,the grey correlation method is used to determine the influencing factors of ’ nature-economy-society ’ and put forward the countermeasures of sustainable land use : strict control of arable land to improve the yield and quality of arable land;increase the area of forest and grassland and maintain a reasonable proportion of water area;pay attention to development and protection to optimize the structure of land use;coordinate economic and social development and industrial structure adjustment;strictly control the emission standard of industrial "three wastes" to reduce environmental pollution;develop highquality ecological industrial system to reduce land pollution;Adjust the population structure and enhance coordination between man and land;reasonably control the proportion of construction land area;reduce the use of chemical fertilizers and pesticides plastic film to enhance land quality;improve laws and regulations and establish an early warning and monitoring system for land ecological security.