The Evaluation Of Ecological Assets In Brahmaputra River Basins

Under the environment of"exploring and compiling the balance sheet of natural resources"proposed at the Third Plenary Session of the Eighteenth Central Committee,in order to provide data support for national and local decision-making and ecological trade-offs among investors,this paper evaluates the ecological assets of the Brahmaputra River basins through RS and GIS for the first time.According to Landsat 8 remote sensing images,the Brahmaputra River basins is divided into seven types of ecosystems:forest land,grassland,agricultural land,waters,swamp,construction land and unused land.Based on the analysis of ecological types,combined with MODIS remote sensing images,meteorological data,DEM data and soil data,the ecological parameters of vegetation coverage(FVC)and net primary productivity(NPP)were determined and calculated.The ecological assets evaluation system in Brahmaputra River basins was established with the organic production value,nutrient cycling value,air quality regulation value,water conservation value and soil-water conservation value as evaluation indexes.According to the evaluation indexes,establish remote sensing models respectively with alternative cost method,market value method,carbon tax method,shadow engineering method and opportunity cost method.The total value of ecological assets in Brahmaputra River basins is estimated to be 127.861billion yuan,averaging 521874.58 yuan/km~2,of which organic production value accounts for1.14%,nutrient cycling value accounts for 4.96%,air quality regulation value accounts for32.28%,water conservation value accounts for 36.64%,water-soil conservation value accounts for 24.98%.The overall performance is:water conservation value>air conditioning value>water-soil conservation value>nutrient recycling value>organic production value.From the perspective of individual ecosystems,the total value of forestland ecological assets is 44.096 billion yuan,and the total value of grassland ecological assets is 48.638 billion yuan,which is the main source of ecological assets in the Brahmaputra River basins.The overall performance is:grassland'value>forest land'value>waters'value>unused land'value>agricultural land'value>Swamp'value>construction land'value.From the perspective of spatial distribution,the higher value of ecological assets is mainly distributed in the middle and lower parts of the Brahmaputra River basins,which is part of the economic center of the Tibet Autonomous Region.It can be seen that the rich forest resources in the lower reaches of Nyingchi County and Medog County have contributed a lot to the ecological assets.According to the width of the river valley,the Milin wide valley in the downstream area has reached more than half of the ecological assets of the Brahmaputra River basins,followed by the Shigatse wide valley with a large area,accounting for 18.87%of the total ecological assets.It can also be seen that forest land and grassland have made great contributions to the estimation of ecological assets.