Quantitative Research On SDGs Related To Terrestrial Ecosystems At County Scale Based On Remote Sensing

The United Nations Sustainable Development Goals(SDGs)have proposed a blueprint for future sustainable development for all countries in the world.The Chinese government has also strongly responded in the promulgation of the Sustainable Development Agenda and attached great importance to the specific implementation of SDGs indicators in my country.In the assessment reports in recent years,Chinese overall ranking in the world has steadily improved,but there are still serious challenges in the scoring of relevant indicators related to the ecological environment.Focuses on the construction and management of the ecological environment are still necessary owing that the evaluation results of China has been in the red and orange scales from the perspective of SDG15,sustainable development of terrestrial ecosystem.Therefore,this study focuses on SDG15 goals and combines other indicators closely related to terrestrial ecosystems to construct a terrestrial ecosystem sustainability evaluation index system,so as to evaluate the situation of sustainable development within the study area and provide theoretical reference value for the localization of SDGs indicators.This study takes the Yangtze River Delta Eco-Green Integrated Development Demonstration Area as the research area.Because the establishment vision of the demonstration area is consistent with the core purpose of SDG15 goals,both highlight the need for “ecological green”,so it is important to evaluate the sustainable development of the demonstration area.It has practical significance and can provide theoretical support for the later planning and construction of the demonstration area.Based on this,this paper firstly constructs a sustainable evaluation index system for terrestrial ecosystems according to the connotation of SDGs indicators,combined with the territorial spatial planning of the demonstration area and the actual situation of the demonstration area,including biodiversity evaluation indicators,land degradation evaluation indicators,forest coverage indicators,Eight evaluation indicators,such as cultivated land holding amount index,per capita green space area index,road network density index,water body area ratio index,and construction land scale index,are used to calculate the weight value of each index using the analytic hierarchy process.Then,preprocess the basic data required for the research,and select 2013,2016,and 2019 for research.The basic data of land use classification used in the index calculation is obtained by visual interpretation,with a spatial resolution of 10 meters,and taking the township as the basic unit of evaluation,it can more accurately show the regional differences of the demonstration area.Combining remote sensing data and social statistical data to calculate each index,and finally weighted,superimposed and normalized the index calculation results to obtain the temporal and spatial changes of the sustainable development of the demonstration area from 2013 to 2019,and further proposed specific measures for the evaluation results.Sustainable development optimization and improvement path.The main conclusions in this research show that:(1)During the study period,the biodiversity level of the demonstration area showed a trend of first decreasing and then increasing.In 2013,2016 and 2019,the area of high-level biodiversity areas accounted for 40.54%,30.63%,and 37.01%,respectively.In 2013,there were 3 townships reached the optimal grade standard,1 in2016,and 3 in 2019.Among them,Zhujiajiao Town had the best biodiversity grade for three consecutive years,and Xujing Town had the best grade for three consecutive years.Red rating;During the period from 2013 to 2019,the biodiversity level of 8 townships showed an upward trend,and 20 townships showed a downward trend,so the biodiversity level of the demonstration area needs to be improved furtherly.(2)Overall,the demonstration area has achieved certain results in curbing land degradation.In 2013-2016,the total degraded land area accounted for 39.14% of the whole study area,and the restored degraded area hold a percentage of 60.86%;between2016 and 2019,the total degraded land area accounted for 39.73%,and the total restored and degraded area accounted for 39.73%.60.27%,the restored area is larger than the degraded area,indicating that all achieve the goal of "land degradation neutrality",but the degraded area shows an increasing trend.At the township level,the proportion of land degradation in 20 townships showed an increasing trend,and 8 townships showed a decreasing trend.(3)The overall sustainable development of the demonstration area showed a trend of first decline and then rising.From 2013 to 2019,the sustainable scores of the demonstration area were 38.96,34.94 and 36.21 respectively.The indicators that showed a better trend during the study period were SDG15.1.1 forest coverage index,SDG9.1.1 road network density index,SDG6.6.1 Water body area ratio indicator,SDG11.3.1 construction land scale indicator;SDG15.1.2 biodiversity indicator,SDG15.3.1 land degradation indicator,SDG2.4.1 cultivated land reserve indicator,SDG11.7.1 per capita green space indicator,the land degradation index is a reverse index,and the increase of land degradation area indicates that the index is getting worse.By calculating the sustainable development status at the township scale,it is found that the township with the highest average score from 2013 to 2019 is Jinze Town with 70.3points,followed by Liantang Town and Xitang Town with scores of 67.73 points and60.26 points,Xujing Town,Xiayang Street and Huaxin Town scored lower,with 7.79,20.68 and 23.03 points respectively.This paper quantitatively analyzes the sustainable development of the terrestrial ecosystem in the demonstration area,and proposes a specific improvement path,which provides a theoretical reference for the planning and construction of the demonstration area,and also provides ideas for the localization research of SDGs at the county scale.