甘肃省1960—2008年潜在蒸散量时空变化及其影响因子

基于甘肃省27个气象站点1960—2008年逐日气温、 降水、 风速、 日照时数、 太阳总辐射和相对湿度数据,应用Penman-Monteith模型和Kriging插值法,分析其潜在蒸散量的时空变化及其影响因子。结果表明:近49 a来,甘肃省不同气候区年均潜在蒸散量变化除河西走廊外均呈上升趋势,并以甘南高寒湿润区上升最显著,变化率为10.36 mm/10 a(α=0.001);在四季变化中,夏季最大,春秋次之,冬季最小,各气候区变化趋势有别。潜在蒸散量空间差异显著,表现为自西北向东南递减,且甘南高原最小,河西暖温带最大。河西、 陇南、 陇中、 甘南及祁连山区年均潜在蒸散量分别与平均风速、 太阳总辐射和最高气温正相关最显著,典型站点与之一致,且辐射项主要受太阳辐射影响,动力项主要受风速影响。

Temporal and Spatial Change of the Potential Evaporation and Its Impact Factors in Gansu Province

Based on the daily temperature,precipitation,wind speed,sunshine hours,total solar radiation and related humidity data of the 27 weather stations of Gansu Province from 1960 to 2008,evapotranspiration(ET0) was estimated with the methods of Penman-Monteith model and the temporal-spatial variation of ET0was analyzed by using Kriging interpolation in different climate regions of Gansu Province.The results indicated that ET0 was different in different climate regions of Gansu and changing trends of ET0 were increasing except for Hexi Corridor.The changing trend of ET0 was increasing most obviously in high-cold humid area of Gannan,the change rate was 10.36 mm/10 a(α=0.001).In four seasons,summer ET0 was maximum,autumn and spring ones occupied the second place,and winter ET0 was minimum.ET0 had the characteristic of remarkable spatial variation,with the decreasing from northwest to southeast,with the smallest in Gannan plateau,while the biggest in the warm temperate zone of Hexi Corridor.But the changing trend was different in different climate regions of Gansu Province.There was remarkable positive correlation between the mean annual ET0 and the annual mean wind speed,the annual total solar radiation,the annual mean highest temperature,respectively in the warm-temperate zone,cold-temperate zone,arid region of Hexi Corridor and Longnan humid region,semi-arid region of Longzhong,Gannan and Qilian mountainous regions of Gansu.Climatic influencing factors of the typical weather stations of each climate region were similar as those of the seven climate regions and the ETrad was mainly impacted by the total solar radiation,while the ETaero was affected by the wind speed.