摘要
利用泾河上游流域1973—2012年的径流和蒸发皿观测资料,验证了该区域蒸散发量存在互补关系;在此基础上,利用区域内1966—2012年的气象资料,采用蒸散发互补关系模型估算区域实际蒸散发量,并进一步分析实际蒸散发的变化趋势及成因。结果表明,泾河上游流域蒸散发互补关系显著,平流—干旱模型计算该区域1966—2012年多年平均实际蒸散发量为529.4mm,总体呈减少趋势,变化率为-4.64mm/(10a)。季节变化上,春、夏、秋季的实际蒸散发量均呈下降趋势,其中夏季实际蒸散发量下降趋势显著,冬季蒸散发略有上升。通过分析实际蒸散发与气象因子的相关关系以及各气象因子变化趋势可知,研究区实际蒸散发的变化与降水、相对湿度和日照时数呈正相关关系,而与风速的变化呈负相关,该区域年实际蒸散发减少的主要原因可能是由于日照时数减少导致太阳辐射能量下降及降水量减少使可供蒸发的水量减少。
Based on the runoff, precipitation and pan evaporation data from the upper reaches of the Jinghe River basin from 1973 to 2012, the complementary relationship of evapotranspiration was analyzed. The monthly actual evapotranspiration from 1966 to 2012 was calculated by the complementary relationship evapotranspiration model, the variation of actual evapotranspiration and its causes were analyzed. The results indicated that there existed an obvious complementary relationship of evapotranspiration in the study area. The average annual actual evapotranspiration in the upper reaches of the Jinghe River basin was 529.4 ram, and it had a downward trend at a rate of 4.64 mm/decade. All of the actual evapotranspiration in spring, summer and autumn presented the downward trend, and the decreasing trend of actual evapotranspiration in summer was significant at the level of 0.01. An upward trend was observed in the actual evapotranspiration in win- ter. Through the analysis of the correlation between actual evapotranspiration and meteorological factors and the changing trend of various meteorological factors, precipitation, sunshine hours and relative humidity have the effective effect on the actual evapotranspiration, while wind has the negative effect. The decrease of actual evapotranspiration is mainly due to the reduction in solar radiation caused by the decrease of sunshine hours and the reduction of the available water for evapotranspiration caused by the decrease of precipitation.
出处
《水土保持研究》
CSCD
北大核心
2016年第2期143-147,共5页
Research of Soil and Water Conservation
基金
国家自然科学基金项目(41301030
41301496
91325201)
关键词
实际蒸散发
蒸散发互补关系
平流—干旱模型(AA模型)
泾河流域
actual evapotranspiration
complementary relationship of evapotranspiration
Advection-Aridity model （AA model）
the Jinghe River basin
