Evapotranspiration Estimation Of Qaidam Basin And Its Impact Factors

Evapotranspiration is composed with soil evaporation and vegetation transpiration, which is the mainway of energy, water transport and transformation in the soil-plant-atmosphere system.48%of solarradiation is consumed in the evaporation process;64%of precipitation get into the atmosphere inevapotranspiration, and it directly involved in the Earth’s water cycle. Evapotranspiration is an importantpart of energy balance and water balance. Accurate measurement and estimation of evapotranspiration isnot only important for studying global climate evolution, environmental issues and water resourcesassessment, but also important for drainage irrigation, monitoring of agricultural drought,and improving theutilization of agricultural water resources.Located in west part of Qinghai Province, Qaidam basin is one of three important inland basins. It‘srich in mineral resources and is called treasure bowl‘. With little precipitation, the eco-environment of thebasin is fragile and overgrazing results in degradation of grassland. The soil salinization is serious and theunreasonable utilization of water resources results in cone of depression. The existing hydrogeologicmaterials can not satisfy the demand of test zone of circular economy, the construction of localdevelopment and utilization of groundwater resource, and evapotranspiration is an impoutant part of thewater cycle, directly or indirectly correlated with elevation,topography,vegetation and some meteorologicalfactors. Therefore, analysis of their relationship is signicant for protection of eco-environment, reasonableutilization of water resources, monitoring of agricultural drought and improvment of economic planBased on surface energy balance system, the evapotranspiration of september from2001to2010and the evapotranspiration on January to December in2010was estimated in thisstudy. The time series variation of evapotranspiration and its spatial distribution was analyzed.The spatial distribution of different type of land use was also analyzed in this study. Therelation between evaporation and meteorological factors (temperature, rainfall, etc),topography and vegetation was discussed at last. The result will provide scientific referencesfor reasonable utilization of water resources in Qaidam basin.