摘要
涪江流域是三峡入库水沙的主要来源地之一。基于涪江流域出口水文站1980~2018年的日径流、输沙率实测数据,从不同时间尺度分析水沙序列、水沙关系特性,并量化气象条件和人类活动两类驱动因素的影响。结果表明:(1)年尺度上,流域多年平均径流量、年输沙量呈显著下降趋势,以1997和2012年为转折年,呈典型的三阶段特性;月尺度上,径流和输沙量主要集中在7、8、9月;日尺度上,径流和输沙的集中度指数分别为0.5、0.91,表明"大水大沙"现象日益突出。(2)基于长时期序列的水沙关系曲线分析结果显示,外界影响因子(a)呈显著上升趋势,河流输沙能力因子(b)呈显著下降趋势;基于洪水场次事件的水沙环路曲线分析结果显示,顺时针和逆时针环路为两类主要的C-Q环路类型,分别呈下降和上升趋势,表明人类活动因素的增加和河流输沙能力的降低。(3)人类活动因素是影响涪江流域水沙变化的主要驱动因素,对径流和产沙量的贡献率占到86%和97%以上。以上结果可为长江流域水沙资源管理提供基础数据和科学依据。
The Fu River watershed is one of the major sources of runoff and sediment into the Three Gorges Reservoir. Based on observations of daily runoff and sediment transport rate from 1980-2018 at the hydrological station of Fu River watershed, this study carried out analyses on runoff-sediment time series and rating curves on multiple temporal scales, and quantitatively differentiated contribution rates of meteorological conditions and human activities. Results showed that:(1) On an annual scale, the means of annual runoff and sediment discharge exhibited significant downward trends and typical three-stage characteristics, taking 1997 and 2012 as the turning years;On a monthly scale, high values of runoff and sediment discharge mainly occurred in July, August and September;On a daily scale, the Concentration Indices of runoff and sediment are 0.5 and 0.91 respectively, indicating that extreme events runoff and sediment became more urgent.(2) Long-term rating curve analyses showed that the external driving factor a presented a significant upward trend, while the sediment transport factor b exhibited a significant downward trend;Event-based analyses on Concentration-Discharge loops showed that, clockwise and counterclockwise loops were two prominent types of C-Q loops. Frequencies of occurrence of the above two types presented downward and upward trends, respectively, demonstrating increased effect of human activities and decreased effect of river sediment transport capacity.(3)Human activities were proved to be the primary driving factor, and corresponding contribution rates to runoff and sediment discharge accounted for more than 86% and 97%, respectively. The above conclusions could provide basic data and scientific evidences for management of runoff and sediment resources in the Yangtze River Basin.
作者
夏绍钦
张会兰
郝佳欣
杨军
XIA Shao-qin;ZHANG Hui-lan;HAO Jia-xin;YANG Jun(Three-Gorges Reservoir Area(Chongqing)Forest Ecosystem Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2021年第7期1603-1613,共11页
Resources and Environment in the Yangtze Basin
基金
中央高校基本科研业务费专项资金(2021ZY50)
国家自然科学基金项目(51309006)
国家重大水利基金项目(12610100000018J129-01)。
关键词
涪江流域
水沙关系
水沙序列
C-Q环路
驱动因素
Fu River watershed
runoff-sediment relationship
runoff-sediment time series
C-Q loop
driving factors
