柴达木流域参考作物蒸散变化成因  

Cause Analysis of Evapotranspiration Variations of Reference Crop in the Qaidam Basin of Qinghai-Tibetan Plateau

作　　者：张存桂[1] 刘峰贵[1] 沈彦俊[1,2] 郑双飞[1] 

机构地区：[1]青海师范大学生命与地理科学学院,西宁810008 [2]中国科学院遗传与发育生物学研究所农业资源研究中心,石家庄520021

出　　处：《南水北调与水利科技》2012年第6期123-127,131,共6页South-to-North Water Transfers and Water Science & Technology

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-EW-J-5);国家自然科学基金项目(40761003)

摘　　要：基于11个气象站点的实测数据,应用Penman-Monteith模型估算并分析了1970年-2010年以来柴达木流域参考作物蒸散(ET0)对气候变量的敏感性及气候变量对ET0的影响。结果表明:(1)41年来柴达木流域的ET0以-17.8mm/10a的变化率呈显著下降趋势,很可能与风速和净辐射的减小有关。(2)ET0对净辐射最敏感,对气温的敏感性最低,且气温的敏感性最不稳定。ET0对实际水汽压的敏感性逐年减小,而对净辐射、气温和风速的敏感性逐年增大。(3)风速是柴达木流域对ET0贡献最大的气候变量;尽管气温的相对变化(64.4%)远远大于风速的相对变化(49.9%),但贡献却小于风速;净辐射和实际水汽压对ET0减小的贡献不明显。结果显示气温对ET0的变化为正贡献,而风速、净辐射和实际水汽压对ET0的变化均为负贡献。Crop reference evapotranspiration （ETo） is often used to determine crop water requirement. In this study, the ETo values were calculated using the Penman-Monteith model based on the 41-year measured meteorological data of daily net radia-tion, actual vapor pressure, mean air temperature, mean wind speed, and precipitation at 11 meteorological stations in the Qai-dam basin during the period of 1970-2010. The sensitivity of ETo to the variation of climate variables was estimated and the effects of climate variables on ET0 were analyzed. The results showed that： （1） Over the past 41 years, the climate in the Qai-dam basin has a trend toward warm-humid conditions, and the ET0 has a decreasing rate of-17.8 mm/10a. From the perspec-tive of qualitative trend analysis, the decreasing of ETo is likely to be associated with the decreasing of wind speed and net radi-ation. （2） In terms of the sensitivity of ETo to climate variables, the sensitivity of ETo to actual vapor pressure decreases every year, but the sensitivities of ET0 to net radiation, air temperature, and wind speed increase every year. ET0 is most sensitive to net radiation while least sensitive to temperature. Also, the sensitivity of ETo to temperature is the most unstable. （3） Over the past 41 years, the relative changes in wind speed reached 49.9%, which contribute the most to ET0 in the Qaidam Basin. Although the relative changes in temperature were up to 64.4%, but their contribution to ETo was less than that of wind speed. Meanwhile, the contributions of net radiation and vapor pressure to ET0 were not obvious. The spatial contribution of temperature to ET0 was positive, while the spatial contributions of wind speed, net radiation, and actual vapor pressure to ET0 were negative. Wind speed was the dominant factor affecting the variations of ET0 in the Qaidam Basin.

关 键 词：柴达木流域 参考作物蒸散 趋势 敏感系数 贡献率 

分 类 号：S161.4[农业科学—农业气象学]