Study On Ecological Footprint And Biocapacity Of Yanhe Watershed

With the development of China's ecological civilization,sustainable development has been established as the core development strategy of the country.It emphasizes the protection of the ecological environment and highlights the importance of following nature's law as the criterion to establish a harmonious relationship between man and nature.To fulfill this target,further research and quantitative analysis of the role of human activities in ecosystems and their impacts on the ecological environment are needed.The Ecological Footprint(EF)and Biocapacity(BC)accounting method can reveal the balance between the demand of human for natural resources and the supply capacity of natural resources,and provide a reference for the quantitative assessment of regional ecological sustainable development.This paper takes a typical ecological environment fragile area,Yanhe Watershed,as the research area.Firstly,the data support role of remote sensing technology in EF and BC accounting process of Yanhe Watershed was discussed.Based on Landsat-5 TM remote sensing image,the MST-NDWI water extraction method was proposed,which effectively solved the problem of water extraction in the Yanhe Watershed.Based on Sentinel-2 MSI remote sensing imagery to construct NDVI time series data,the method of extracting cultivated land information was studied.For non-spatial statistical data,the statistical data was estimated and then extended to the Yanhe Watershed through the spatial heterogeneity of land use data.The EF and EC improvement model with “watershed hectare” as the accounting unit is constructed and key parameters of the model are corrected based on local data.Finally,the EF and BC of the Yanhe Watershed are completed under the watershed scale utilizingthe revised model.By analyzing the accounting results of Yanhe Watershed in 2000,2010 and 2017,the quantitative indicators of regional Ecological Reserve(ER)/Ecological Deficit(ED)were further obtained.In 2000,the per capita ER of Yanhe Watershed was 0.15 hectares;in 2010,the per capita ED was 1.92 hectares;in 2017,the per capita ED was 1.41 hectares,which was better than 2010.The preliminary conclusions are as follows:1)In recent years,the use of natural resources by human activities in the Yanhe Watershed has exceeded the rate of renewal of natural resources.The influence of human activities in ecologically fragile areas has significantly affected regional sustainable development;2)the pivotal reason for the ED in the Yanhe Watershed is closely related to the economic growth mode of Yan'an City,which is the mainstay of the development of petroleum heavy industry;3)the stability of the ecosystem in Yanhe Watershed has been effectively improved through carrying out ecological environment construction and restoration projects,which have played an important role in improving the status of ecological environment and sustainable development.This paper provides suggestions for the sustainable development of Yanhe Watershed from the perspective of EF and BC,and explores how humans can protect Earth's tolerance under the condition of extreme dependence on natural resources.