摘要
径流量、输沙量一定程度上可反映流域的环境特性以及水土流失程度。拉萨河作为雅鲁藏布江的一级支流,对其输沙量的长期变化特征以及影响因素缺少精确定量评估。开展拉萨河水沙变化特征及归因识别研究,分析西藏农业及生活用水的格局,对区域生态保护和高质量发展具有重要意义。本文基于1980—2018年拉萨水文站径流泥沙和流域降水数据,采用Mann-Kendall趋势分析、小波分析和双累积曲线等方法分析了拉萨河近40 a的径流、输沙演变规律和周期性特征,并结合降水变化和人类活动探讨了流域水沙变化的主要影响因素。研究结果表明:(1)近40 a拉萨河年径流量和输沙量整体均表现为不显著的增加趋势,其多年变化呈多峰波动,逐年变化方向基本同步;二者年内分配极为不均,汛期(5—10月)径流量占全年总径流的85.79%,输沙量占比达99.62%。(2)年径流量在2005年发生突减变化,年输沙量分别在1994年和2005年发生突增和突减变化。(3)拉萨河年径流量近40 a经历了3次丰-枯循环交替变化,15 a为主周期;年输沙量经历了6次丰-枯循环交替变化,9 a为主周期。(4)拉萨河径流变化的主要影响因素由降水主导(1994—2004年)转变为人类活动(2005—2018年)占主导,而输沙变化的主要影响因素则表现相反;随着不同阶段的变化,人类活动对径流输沙的贡献率逐步增大,生产建设工程、水库运行调度、生态工程实施是人类活动影响拉萨河水沙变化的主要表现形式。研究结果可为流域水资源分配以及水利工程建设提供科学依据,同时为流域生态工程实施成效评估提供数据支撑。
The runoff and related sediment migration in a valley substantially embody the changes in environment and the situation of water and soil loss. As one of the major tributaries of the Yarlung Zangbo River, the variations on runoff and sediment load in the Lhasa River are crucial to agricultural and domestic water consumption in the Tibet Autonomous Region. However, there was little quantitative analysis about the changes in sediment transportation and the associated influencing factors. In this study, it conducted an investigation into the long-term formation of runoff and sediment load for the past 40 years in the Lhasa River basin by examining data of 1980-2018 collected at field observations, including runoff and sediment load, meteorological data;The Mann-Kendall trend analysis, wavelet analysis, and double mass curve method were jointly used for the analysis of the impact of precipitation and human activities on variation in runoff and sediment load. The results showed that:(1) There was an increasing but insignificant tendency in annual runoff and sediment migration in the past 40 years, while they displayed the multi-peak fluctuation characteristics, and the annual change trend between runoff and sediment load was similarly synchronous;the intra-annual distribution of runoff and sediment load was extremely uneven, mainly concentrated in the monsoon season(from May to October), accounting for 85.79% and 99.62% of the annual total runoff and sediment discharge, respectively.(2) The annual runoff had a decreased abrupt point in 2005, and the annual sediment transportation increased and decreased dramatically in 1994 and 2005, respectively.(3) There have been three drying-wetting transitions in runoff with a main fluctuation period of 15 a during the last 40 years, and six drying-wetting transitions in sediment discharge with a main fluctuation cycle of 9 a.(4) The dominant factors of runoff change shifted from precipitation(1994-2004) to human activities(2005-2018) in the Lhasa River, which was the opposite fo
作者
张闻多
熊东红
张宝军
赵冬梅
刘琳
秦小敏
ZHANG Wenduo;XIONG Donghong;ZHANG Baojun;ZHAO Dongmei;LIU Lin;QIN Xiaomin(Key Laboratory of Mountain Hazards and Earth Surface Process,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources,Chengdu 610041,China;Graduate University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《山地学报》
CSCD
北大核心
2022年第5期670-681,共12页
Mountain Research
基金
第二次青藏高原综合科学考察研究(2019QZKK040403)
中国科学院战略性先导科技专项(A类)(XDA20020401)。
关键词
径流量
输沙量
双累积曲线
降水
人类活动
拉萨河
runoff
sediment migration
double cumulative curve
precipitation
human activity
the Lhasa River
