Evaluation Of Ecosystem Services In Karst Basin Based On InVEST Model

The diversity of ecosystem service functions plays a vital role in the sustainable development of the natural ecological environment and human society and economy.With the population growth and rapid economic development,the unreasonable development and utilization of natural resources by humans have led to ecological System environmental problems are becoming more and more prominent,which further deteriorates the ecosystem service function.The rational and scientific assessment of the various functions of the ecosystem has important guiding significance for the sustainable development of the economy and the sustainable use of natural resources in the region and the maintenance of the balance of the natural system,which can provide scientific management and planning for related departments.reference.The karst development in the Zunyi section of the middle reaches of the Wujiang River Basin is obvious.The topographic difference in the basin is large,and the rapids are mostly typical mountainous watersheds.Not only is it an important part of the entire Wujiang River Basin,but also an important ecological barrier and water conservation area in the upper reaches of the Yangtze River Basin.In this paper,the Zunyi section of the middle reaches of the Wujiang River Basin in Guizhou is taken as the research area.Based on RS and GIS technology,the soil erosion changes in the study area are calculated by GIS spatial analysis,and the InVEST model is applied to the Zunyi section of the middle reaches of the Wujiang River Basin in 2000,2005,2010,and 2015,respectively.The water production,carbon storage,and habitat quality functions of the five phases of the year and 2017 are dynamically evaluated.Analyze the spatial change characteristics of three ecological service functions and the ecological function under different land use types in different periods,and finally divide the importance of each ecological service function by integrating them.The main findings are as follows:(1)From 2000 to 2017,the land use types in the study area were mainly forest land and dry land,and the dry land was mainly converted into forest land and grassland.(2)From 2000 to 2017,the soil erosion in the study area was mainly light,followed by moderate erosion.With the implementation of returning farmland to forests and grasslands,the area of moderate erosion,strong erosion,very strong erosion,and severe erosion has been reduced.(3)The spatial distribution of the fifth-stage water production in the study area from 2000 to 2017 all showed a trend of gradual increase from southwest to southeast.In the past 17 years,the overall change trend of water production in the study area has decreased first and then increased.Its spatial distribution and change trend characteristics have a direct relationship with rainfall,terrain,temperature,and vegetation coverage.(4)From 2000 to 2017,the spatial distribution pattern of carbon storage function in the study area did not change much.The areas with higher carbon storage values were mainly located in the middle and southeast of the study area,and the lower areas were mainly located in the southwest.In the past 17 years,total carbon stocks have shown a trend of decreasing first and then increasing.(5)From 2000 to 2017,the spatial distribution pattern of habitat quality in the study area changed little,and the areas with improved habitat quality were mainly distributed in the central,northern,and southeastern regions.The habitat quality index showed an overall upward trend,with evergreen broad-leaved forest having the highest habitat quality index,followed by deciduous broad-leaved forest,coniferous and broad-leaved mixed forest,shrub forest,and grassland.(6)The important ecological function division of three ecosystem service functions from 2000 to 2017 was analyzed.It was found through analysis that the three ecosystem service functions of water production,carbon storage and habitat quality are all very important.The area is30.13km~2,Accounting for 0.15%of the total area of the study area,where the terrain is relatively high and the distribution is relatively scattered,mainly concentrated in coniferous and broad-leaved mixed forest,evergreen broad-leaved forest,deciduous broad-leaved forest area.