金沙江下游流域大气降水氢氧稳定同位素特征及水汽来源  

Hydrogen and Oxygen Stable Isotopic Characteristic and Moisture Sources of Precipitation in the Lower Jinsha River Basin

作　　者：金可 于江 张乾柱[1] 周火明[1] 万丹 赵姹 胡月 吴颐杭 JIN Ke;YU Jiang;ZHANG Qian-zhu;ZHOU Huo-ming;WAN Dan;ZHAO Cha;HU Yue;WU Yi-hang(Chongqing Branch,Changjiang River Scientific Research Institute,Chongqing 400026,China;Environmental Protection Department of China Three Gorges Projects Development Co.,Ltd.,Chengdu 610023,China)

机构地区：[1]长江科学院重庆分院,重庆400026 [2]中国三峡建工(集团)有限公司环境保护部,成都610023

出　　处：《长江科学院院报》2024年第5期26-34,共9页Journal of Changjiang River Scientific Research Institute

基　　金：国家重点研发计划项目(2021YFE0111900);中央级公益性科研院所基本科研业务费项目(CKSF2021464/CQ,CKSF2023299/CQ);乌东德、白鹤滩水电站消落带修复试验项目(JG/19042B,JG/19043B)。

摘　　要：金沙江下游流域地处干热河谷气候影响区,大气降水对该区域水文循环至关重要。分析了金沙江下游流域降水稳定同位素组成的季节变化特征及其影响因素,结合同位素示踪和HYSPLIT模型探讨了流域大气降水水汽来源。结果表明:金沙江下游流域降水δ^(2) H和δ^(18) O雨季偏负而旱季偏正,气温和降水量对同位素组成影响较大而高程效应不显著;流域大气降水线斜率和截距均低于全球和我国大气降水线,主要受到非平衡蒸发作用影响;流域大气降水水汽来源和昆明地区类似,雨季降水主要受到西南与南亚季风影响,旱季降水潜在来源为西风带或极地大陆气团。研究成果对金沙江下游区域水文循环具有重要指导意义。The lower Jinsha River Basin is situated in a region impacted by dry and hot valley climate.Atmospheric precipitation plays a pivotal role in the hydrological dynamics of the basin.We scrutinized the seasonal fluctuation patterns of stable isotopic composition in precipitation within the basin,and identified its influencing factors.Furthermore,employing isotope tracing techniques alongside the HYSPLIT(Hybrid-Single Particle Lagrangian Integrated Trajectory)model,we elucidated the sources of atmospheric precipitation in the area.Findings reveal distinctive seasonal trends in isotopic values,with negative values ofδ^(2) H andδ^(18) O observed during rainy season and positive values in dry season.Temperature and rainfall emerge as primary influencers on the isotopic composition of local precipitation,while elevation exerts minimal impact.Notably,the local meteoric water line exhibits lower slope and intercept values compared to global and Chinese atmospheric precipitation lines,primarily due to non-equilibrium evaporation effects.Moisture sourcing analysis indicates a similarity between the precipitation origins in lower Jinsha River Basin and those in Kunming.Rainfall during the rainy season predominantly stems from the southwest and south Asian monsoons,while dry season precipitation potentially results from the westerly belt or polar continental air masses.These research outcomes are of substantial significance for understanding regional hydrological cycle within the lower Jinsha River Basin.

关 键 词：大气降水 氢氧稳定同位素组成 影响因素 水汽来源 金沙江下游流域 

分 类 号：P426[天文地球—大气科学及气象学]