第二松花江流域实际蒸散发的时空变化特征和影响因素

Spatiotemporal variation characteristics and related affecting factors of actual evapotranspi- ration in the second tributary of the Songhua and River basin,Northeast China.

根据1971—2012年气象、水文资料和基于互补相关理论的平流-干旱模型,采用线性趋势分析、Mann-Kendall秩次相关检验、反距离加权(IDW)插值、Pearson相关系数等方法研究了第二松花江流域实际蒸散发(ET a)的时空变化特征和影响因素。结果表明:第二松花江流域多年平均实际蒸散发量为435.99 mm,1971—2012年实际蒸散发量以11.82mm·10 a-1的速率呈显著的上升趋势,并与流域潜在蒸散发的下降存在互补关系,春夏秋季实际蒸散发的上升对年际尺度实际蒸散发的上升具有明显的贡献;流域南部河源区以及北部流域下游存在两个高值中心,年实际蒸散发量分别为540.7和461.1 mm,低值中心在中部的吉林,年实际蒸散发量为223.0 mm;整个流域实际蒸散发量均呈一致的上升趋势,但其北部置信度较南部高;平均气温、最高气温、最低气温、气压、实际水汽压的上升造成辐射能量项的上升,是造成实际蒸散发上升的主要原因;风速下降和实际水汽压的上升使空气动力学项呈现减少趋势,空气动力学项的减少在一定程度上贡献于实际蒸散发的增加。

By using the meteorological and hydrological data in 1971-2012 and the Advection- Aridity model which is based on the complementary relationship method, this paper studied the spatiotemporal variation of actual evapotranspiration （ETa ） and related affecting factors in the second tributary of the Songhua River basin, China by the linear trend analysis, Mann-Kendall rank correlation analysis, Inverse Distance Weighted interpolation method, and Pearson＇ s corre- lation coefficient. In the second tributary of the Songhua River basin, the average annual actual ETa was 435.99 mm. The actual ETa in 1971-2012 had a significant increasing trend with a rate of 11.82 mm · 10 a^-1 , and showed a complementary relationship with the decrease of potential e- vapotranspiration. The increase of the actual annual ETa in spring, summer, and autumn had an obvious contribution to the increase of yearly actual ETo. There were two centers of high ET in south area （540.7 ram） and north area （461.1 mm）, and one center of low ETa（223.0 mm） in the central part of Jilin City. The actual ETa in the whole basin showed a consistent increasing trend, but the confidence was higher in northern basin than in southern basin. The increase of average air temperature, maximum air temperature, minimum air temperature, atmospheric pres- sure, and actual water vapor pressure in this basin caused the increase of the radiation-energy item, and then, caused the increase of the El＇. The decrease of wind speed and the increase of actual water vapor pressure contributed more to the decrease of the aerodynamics item, and the final effect was to accelerate the increase of the ETa.