The Study Of Land Use Status And Ecosystem Service Value In Endorheic Basin

Land use and land cover is one of the important fields of global environmentalchange studies. Shiyang River lies at the eastern part of Hexi Corridor in GansuProvince, and is one of three main endorheic rivers in Hexi Corridor. In the past years,influenced by excessive human activities, several ecological and environmentalproblems appeared in Shiyang River Basin, including the decrease of natural supplyfrom groundwater, regional groundwater recession, land desertification, soilsalinization and vegetation degradation. At the same time, great changes of land usehave taken place in study area. So the research on land use change in Shiyang RiverBasin is helpful for understanding the ecological process and human’s influence, andcan provide a scientific reference of regional sustainable development.Based on the data derived from Landsat TM imagery acquired in2000and2010,with the help of GIS technology, mathematics model and landscape ecology theory,the land use change of seven counties and districts （Minqin County, LiangzhouDistrict, Jinchang City, Yongchang County, Gulang County, Tianzhu County, andSunan County） in Shiyang River Basin was investigated, including the structure, rateand degree changes of land use, and relative change rate and transfer of land use types,as well as spatio-temporal characteristics of ecosystem service value （ESV）, spatialgradient differentiation, and sensitive analysis. The conclusions are as follows:（1） According to the data of remote sensing in2000and2010, we found the landuse types in Shiyang River Basin change significantly in the past decade, especially ofcultivated land, unutilized land and grassland, cultivated land, forest land andgrassland generally decreased, unutilized land generally increase and in the middleand lower reaches of the drainage basin.（2） The spatial analysis of ESV showed that ESV per unit area changes with anobvious gradient from upstream to downstream in the whole basin, and the order ofESV is Tianzhu County> Sunan County> Gulang County> Jinchang City>Liangzhou District> Minqin County. ESV in the upstream mountain area is abouttwice as that in the middle reaches (up to800000yuan RMB·km²a^-1), and that in thedownstream area is the lowest (only150000-250000yuan RMB·km²a^-1). （3） All the sensitivity coefficient of ESV on total ESV are less than0.5,especially of waters and unutilized land （less than0.1）, and the order is grassland>forestland> cultivated land> unutilized land> waters.（4） According to the spatio-temporal differentiation of ESV, ESV in the middleand lower reaches with relatively poor ecological environment showed a decreasingtrend, but that in the upper reaches with nice ecological environment was increasing,and the change in the middle and lower reaches were more significant than that in theupper reaches. The ecological environment protection and treatment in the habitationof downstream area is the vital part of comprehensive control in Shiyang River Basinin the future.