Refined Spatial Simulation And Analysis Evaluation Of Ecosystem Services In Beijing-Tianjin-Hebei Region

The Beijing-Tianjin-Hebei region is an important ecological barrier in the North China Plain,and it is also the region with the largest economic scale and the highest development level in northern China.With the accelerating process of urbanization,the contradiction between people and land in the Beijing-Tianjin-Hebei region has become increasingly prominent,the ecological environment has become increasingly fragile.In order to better realize the major national strategy of Beijing-Tianjin-Hebei coordinated development and achieve sustainable development,it is particularly important to carry out fine spatial simulation and analysis and evaluation of ecosystem service function in Beijing-Tianjin-Hebei region.Based on multi-source data such as high-precision land use data,DEM data,rainfall data,soil data and statistical yearbooks,this thesis simulates and analyzes four key ecosystem services in Beijing-Tianjin-Hebei region,including water conservation,soil conservation,urban heat dissipation and carbon storage,which are closely related to the current ecological environment protection and restoration.The main research contents and conclusions are as follows:(1)The InVEST model was used to evaluate the four ecosystem services of water conservation,soil conservation,urban heat dissipation and carbon storage in2017 and 2018 respectively,and then analyze and explore them from the perspectives of time and space.The analysis results show that:Water conservation increased 14.64mm in the two years,with a total increase of 202 million cubic meters.Spatially,the water conservation conditions in the western mountainous areas were better than those in the southern plains.Soil conservation service increased by 1.68×10~8t in the two years,showing high mountain area and low plain in space.The change range of urban heat dissipation function in two years is small,and the urban heat dissipation function in northern and western mountainous areas and eastern coastal areas is better.The carbon storage function increased by 0.29 Tg in two years,and the carbon density in mountainous areas was higher than that in plain areas.Overall,the ecosystem service function in the north and northwest of Beijing-Tianjin-Hebei region is better than other cities.Water conservation and soil conservation function in most areas of the study area show a gain state,and HMI and carbon storage function in most areas show a loss state.(2)By using the hotspots analysis and Geodetector to analyze the cold and hot spots and influencing factors of various ecosystem services,it is concluded that:The results showed that the hot spots of water conservation were located in the eastern plain area with high rainfall,the hot spots of soil conservation were distributed in the mountainous areas in the central and western regions,and the hot spots of HMI and carbon storage were distributed in the mountainous areas in the northwest and north.Ecosystem services are mainly affected by natural factors.Rainfall is the dominant factor of water conservation,and elevation is the dominant factor of soil conservation,HMI and carbon storage.From the perspective of human activities,construction land occupation has the greatest impact on soil retention,HMI and carbon storage.In summary,the interaction of any two influencing factors is higher than that of a single factor,and elevation is the most important factor affecting the ecosystem service function.The possible reason is that in areas with high elevation,vegetation coverage is high,human activities are less,and disturbance to ecosystem services is less.(3)By using the Moran index and the difference comparison method to analyze the trade-off and synergy of ecosystem services,it is concluded that:There is spatial autocorrelation between any two ecosystem services.Water conservation,soil conservation and carbon storage are mainly synergistic.The main trade-off between the HMI and the other three may be due to the large-scale decline of the HMI index in the northwestern and northern mountainous areas during the study period,while the other three mainly show a gain state in these areas.The synergistic relationship mainly occurred in the northern and northwestern mountainous areas,which may be due to the retention of water and soil in areas with high vegetation coverage,and the interception ability is strong.(4)By using K-means clustering analysis,the Beijing-Tianjin-Hebei region is divided into four ecosystem service clusters:urban living area,water conservation area,carbon sequestration function area and ecological balance area.The same cluster has obvious spatial correlation,and there are obvious differences between different clusters.Urban functional areas are mainly distributed in plain areas,water conservation areas are mainly distributed in the western and central foothills,carbon sequestration areas are mainly distributed in the western and northern mountainous areas,and ecological balance areas are mainly distributed in the central foothills.