Ecological Service Assessment Of Lhasa River Basin Based On SWAT Model

Ecosystem of Qinghai-Tibet Plateau vulnerable to human and climate.Ecological service assessment can clearly reflect the problems of ecological protection and resource utilization policies.Therefore,it is important to evaluate the ecological services of the Qinghai Tibet Plateau.Based on data from 1980 to the present,this paper established the SWAT model of the Lhasa River Basin and analyzed the changes of hydrological components.This paper improved the ecological service assessment method and given suggestions for ecological protection.Results are as follows:(1)Both the coefficient of determination and the Nash coefficient of the SWAT model were above 0.8.Hydrological components of sub-basin included precipitation,evapotranspiration,water production,surface water catchment and underground water catchment.The results showed that the trend of hydrological components decreases from east to west,except for evapotranspiration.There was a large downward trend in precipitation from 2005 to 2010,and a small upward trend after 2010.(2)Precipitation in the Lhasa River Basin was less than the sum of water production and evapotranspiration.Glacier meltwater in the Lhasa River Basin accounts for a high proportion of runoff.In most years,precipitation and glacial meltwater in the Lhasa River Basin were not stored in the soil.Water flowed out of the basin in the form of evapotranspiration or runoff.Therefore,the ecological service assessment method of the Lhasa River Basin should use water supply instead of water conservation.(3)The ecological service assessment included material production,tourism,biological protection,soil and fertilizer conservation,carbon fixation and oxygen release,and water supply.High ecological service values gradually move from southeast to south.From 2000 to 2010,water supply,carbon fixation and oxygen release accounted for a relatively high proportion in ecological services.After 2010,tourism accounted for a relatively high proportion of ecological services.This indicated that local ecological services are gradually affected by social factors(4)Ecological services in ten counties and one protected area of the Lhasa River Basin were analyzed.Nagqu,Sangri,and Kali should focus on grassland restoration.The remaining counties should focus on the ecological impact of tourism growth.Protected area had a significant role in promoting ecology.