全球河流输沙量分布格局及其影响因素

The Distributional Patterns of Sediment loads of Global Rivers and Influencing Factors

研究河流输沙量具有重要的理论和实践意义。近60年在气候变化和人类活动日益增强的背景下,全球众多河流输沙量都发生显著变化。基于全球河流输沙量数据库和区域河流输沙量研究成果,从全球尺度对全球河流输沙量现状、输沙量空间分布格局及其影响因素、输沙量变化及其影响因素3方面进行分析研究。结果表明:(1)全球河流年均总输沙量在2×10^(10) t左右,对全球主要36条河流输沙量数据分析表明大多数河流输沙量显著减少;(2)地质地貌条件是河流输沙量控制性因素,气象水文条件和人类活动对河流间输沙量差异的贡献大致相当;(3)对各气候带的代表性河流研究表明,相比较气候变化,全球河流输沙量变化主要受人类活动的影响。未来全球河流总输沙量会因人类活动尤其是大坝建设的影响而继续减少。

Sediment load research is of important theoretical and practical significance.In the past 60 years,with the increasing climate change and human activities,the sediment loads in many world rivers have undergone significant changes.Based on global sediment database and regional river studies,status,distribution patterns,and influencing factors of suspended sediment loads（SSL）of global rivers were reviewed.The results showed that：（1）Before the proliferation of dam construction in the latter half of the 20^th century,the annual SSL of global rivers was around 2×10^10t.New data of 36 rivers indicated that most global rivers had a decreasing trend in SSL.（2）Geology and geomorphology conditions were decisive factors controlling SSL on a global scale.Meteorological and hydrological conditions and human activities had comparable contributions in controlling the difference in SSL among rivers.（3）Representative river studies in various climatic zones showed that changes in global SSL were mainly affected by human activities.In the future,the total SSL of global rivers would continue to decrease due to the impact of human activities,especially dam construction.