金沙江流域石鼓断面上游水汽含量与降水量特征

Characteristics of Water Vapor Content and Precipitation in the Upstream of Shigu Section in Jinsha River Basin

在流域尺度上研究水文循环过程中的水汽含量和降水量,为流域综合治理和水资源开发利用提供依据。基于ASTER GDEM V2地形数据、ERA-Interim逐月再分析资料及降水资料,研究金沙江流域石鼓断面上游上空水汽含量和降水量的时空分布特征,并讨论两者的相关性。研究表明:研究区上空水汽含量由南向北、由东向西呈递减趋势,西南部呈斜倒“U”型,东南部呈正“U”型;多年平均降水量自西北向东南逐渐增加;年平均水汽含量和降水量呈现上升趋势,四季水汽含量和降水量从大到小均依次为“夏、秋、春、冬”,多年平均月水汽含量和降水量为单峰型分布;年平均水汽含量同降水量之间为弱相关关系,各季节相关性差异显著,逐月相关性更具有指导意义。

The water vapor content and precipitation in hydrological cycle process are studied on basin scale to provide a basis for the comprehensive management of river basin and the development and utilization of air water resources. Based on topographic data ASTER GDEM V2,ERA-Interim monthly reanalysis data and precipitation data, we studied the temporal and spatial characteristics of water vapor content and precipitation over the upper reaches of Shigu Section in the Jinsha River basin, and discussed the correlation between the two. Our research reveals that the water vapor content over the study area displays a decreasing trend from south to north and from east to west, an oblique “U” shape trend in the southwest, and a positive “U” shape in tthe southeast. The average precipitation over the years has gradually increased from northwest to southeast. The annual average water vapor content and precipitation are on the rise. The water vapor content and precipitation in summer are the largest, followed by those in autumn, spring and winter in sequence. The average monthly water vapor content and precipitation for many years distribute in a unimodal type. Moreover, the annual average water vapor content is weakly correlated with precipitation, and the correlation differs significantly among four seasons. The monthly correlation is more instructive.