| Evaporation plays an important role in grassland productivity,biodiversity and stability,so the study of evaporation change of degraded grassland in Inner Mongolia is helpful to understand the water cycle of degraded grassland ecosystem in this area.It also provides an important basis for the rational utilization of grassland water resources in this area.In this study,Duolun County,Inner Mongolia,was used to retrieve the spatial distribution and variation of vegetation coverage and daily evaporation in Duolun County,Inner Mongolia,by using the MODIS data of the growing period in 2017.The effects of land use and grassland degradation on evaporation were analyzed.The results show that:(1)It is feasible and reasonable to use SEBAL model to retrieve daily evaporation in Duolun County.(2)Except for humid grassland,the distribution of daily evaporation of other vegetation types is consistent with the distribution of vegetation coverage in space.(3)Under different land use types,the forest has the highest vegetation coverage,followed by farmland and residential construction land;The daily evapotranspiration is the highest,followed by forest land and farmland.(4)? and ? grassland were the main grassland in the study area,accounting for 98%of the total grassland area.The area of low grade grassland showed a downward trend,while the area of high quality grassland showed an upward trend,which indicated that the grassland environment of Duolun County had been improved to a certain extent.(5)The vegetation coverage and daily evaporation of grassland in the study area showed synchronous interannual dynamic changes.Except for the decreasing trend of daily evaporation of grade I grassland,the change of daily evaporation of other grades of grassland was not obvious.(6)Vegetation coverage in the study area is an important factor to determine the daily evaporation,and the daily evaporation increases gradually with the increase of vegetation coverage. |
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