Quantitative analysis of causes for temporal and spatial variation characteristics and evolution of potential evapotranspiration in Gansu Province during recent 30 years
Evapotranspiration is an important part in the water and energy balance of earth's system.The research on the variation of potential evapotranspiration (ETp) is of great significance for a better understanding of the impact of climate change on hydrological cycle and water resources allocation. Based on Penman-Monteith model recommended and revised by FAO,by use of meteorological data collected from 32 meteorological stations in or around Gansu,the paper analyzed the spatial and temporal variation characteristics of potential evapotranspiration in recent 30 years. Moreover,it analyzed the sensitivity of meteorological factors to potential evapotranspiration and the spatial distribution of sensitive coefficient,and quantitatively reveal the dominant factor of ETp's variation.The result can provide reference for studying the impact of climate change on hydrological cycle,improve agricultural irrigation efficiency,adjust utilization structure of water resources and optimizing the allocation of water resources in Gansu Province.