基于潜在蒸散量对青海湖流域干旱气候以及影响因素的分析  

Evaporation and its impact upon drought climate around the Qinghai Lake Basin based on potential Evaporation

作　　者：白爱娟[1,2] 假拉 徐维新[1,4] 

机构地区：[1]中国气象局干旱气候变化与减灾重点开放实验室,甘肃兰州730020 [2]成都信息工程学院大气科学学院,四川成都610225 [3]西藏自治区气象台,西藏拉萨850001 [4]青海省气象科学研究所遥感中心,青海西宁810001

出　　处：《干旱区地理》2011年第6期949-957,共9页Arid Land Geography

基　　金：国家自然科学基金面上项目(40975020);"十一五"国家科技支撑计划项目(2007BAC30B05-4);干旱气象科学研究基金项目(IAM200812);成都信息工程学院科研项目(KYTZ200914)共同资助

摘　　要：通过分析青海湖流域及周边地区的潜在蒸散量及其水平分布与年内和年代际变化特征,并与中国其它流域的蒸发皿观测和估算的蒸发量变化特征进行对比,得出了青海湖流域干旱气候特征与潜在蒸散量的关系。结果表明:青海湖流域以西干旱沙漠地区是潜在蒸散量的高值区,流域以东是潜在蒸散量的低值区,青海湖是从干旱的高蒸发量区向半干旱的低蒸发量区的过渡地带,体现了其作为"我国西北生态保护的天然屏障"作用。总体而言,近37 a来青海湖流域潜在蒸散量有减弱的趋势,但在1985年以后呈上升趋势,这与黄河上游地区蒸发皿蒸发量和其它方法估算的蒸发量变化结果相似,与我国其它流域蒸发量变化特征也相似,与预期的随着西北地区气温显著升高,蒸发量相应增加的结论相反,与青海省西北部和东南部蒸发量的增加趋势也相反。虽然青海湖流域的潜在蒸发量与气温有显著的正相关关系,与降水量有负相关的关系,但青海湖流域蒸发量的变化是多个要素综合的结果,简单地从气温的升高得到蒸发量增强会引起谬误。青海湖流域潜在蒸散量减弱的趋势,以及降水量的增加,使青海湖流域的干旱气候有所缓解。This paper valued the potential evaporation around the watershed of Qinghai Lake basin,as well as its neighborhood,and analyzed the spatial distribution,its yearly and monthly variability.Additionally the characteristics of potential evaporation over Qinghai Lake were compared with that over other rivers and lakes in China.At last,the relationship between the drought climate and potential evaporation were explored over Qinghai Lake basin.All the results show that,the potential evaporation over the southern part of Qinghai Lake watershed is the highest value,where there is the arid desert area,while over the eastern part of the watershed,the semi-arid area and agricultural region,the potential evaporation is much lower.As a result,the watershed of Qinghai Lake is the important transitional area from high-evaporation arid climate area to semi-arid moisture area,which is a significant barrier for ecology environment over northwest China.During the past 37 years,the potential evaporation over the Qinghai Lake displayed a decreasing trend,which is similar with either calculated or pan-observed evaporations in the upper reaches of the Yellow River.At the same time,the decreasing trend of potential evaporation is similar with other rivers and lakes over China.But the evaporation did not increased as the scientists had estimated,because they think that with the increasing temperature the evaporation should have increased.It is not the same with the northwestern and southeastern part of Qinghai Province,where the evaporation has increased significantly.In one word the evaporation was not only influenced by temperature and rainfall markedly,but also influenced by a lot of other meteorology factors.There would be a mass if you want to get the result that the evaporation will get up just based on the increasing temperature.The decreasing trend of evaporation and increasing precipitation over Qinghai Lake basin,are all the factors that weaken the arid climate of Qinghai Lake during the past presently years.

关 键 词：青海湖流域 潜在蒸散量 气候 降水量 干旱 

分 类 号：P426.2[天文地球—大气科学及气象学]