河西走廊潜在蒸散发时空格局变化与气象因素的关系OA北大核心CSTPCD

Several factors affect the evapotranspiration process.Potential evapotranspiration(ET0)interacts with meteorological variables in a complex manner.Therefore,there is an urgent need to determine the response mech-anism of ET0 changes to meteorological variables.Based on meteorological data from 21 meteorological stations in the Hexi Corridor,Gansu Province,China and its surrounding areas,qualitative and quantitative methods were adopted to reveal the spatiotemporal variation of ET0 and to clarify the sensitivity of ET0 to changes in various meteorological factors and contributions by taking two spatial scales of the Hexi Corridor as a whole and three subdistricts.The results showed the following:(1)ET0 in both the Hexi Corridor and the subdistrict showed a sig-nificant fluctuating upward trend(Z>1.98),with a linear change rate of 2.94 mm·a-1,and the most obvious change was observed in the Heihe subdistrict.(2)ET0 increased from the southeast to northwest.It was smaller in the Shi-yang River subdistrict(1003.78 mm)and Heihe subdistrict(1031.30 mm)in the central and eastern parts of the Hexi Corridor,and larger in the Shule River subdistrict(1171.89 mm)in the western part of the Hexi Corridor.(3)The sensitivity of ET0 to changes in meteorological factors in the Hexi Corridor was ranked as relative humidi-ty(RH),daily maximum temperature(Tmax),sunshine duration(n),average wind speed(u),and daily rainfall(P),with ET0 being the most sensitive to decreases in RH and least sensitive to changes in P.(4)The increase in u was the main cause of the increase in ET0 in the Hexi Corridor,followed by a decrease in RH,increase in Tmax,and in-crease in n.(5)The ET0 in the subdistricts of the Shule River,Heihe River,and Shiyang River showed an increas-ing change,with the factors that contributed the most being Tmax(5.13%),u(8.22%),and Tmax(5.97%),respective-ly,and the factor that contributed the least being n.Variations in wind speed and air temperature were important factors that influenced the ET0 change in the Hexi Corridor.The research results are significant for the rational planning of irrigation water use and improvement of the utilization efficiency of agricultural water resources.