大通站水沙关系演变驱动因素分析

大通水文站是长江进入河口的第一个关键界面,其水沙关系的变化不但直接影响河流本身的发展演变,也影响着河口三角洲的发育过程。深入研究大通站水沙关系的驱动因素,有助于更好地认识长江流域的输沙规律,可为流域地貌演变和对人类活动响应的深入研究提供科学依据。本文基于数理统计方法,重点从降水变化、径流变化、水利水土工程等方面定性定量地研究了气候变化和人类活动对大通站水沙演变过程的影响,结果表明:1954—2000年间降水量和输沙量变化特征较为一致,说明气候变化在一定程度上影响着大通站泥沙输移的变化过程,其更多地体现在对泥沙输移长期性变化的影响方面;2001—2010年输沙量急剧下降,大型水利工程的实施等人类活动对泥沙输移的影响是近10年来大通站入海泥沙急剧变化的直接诱因和主要原因,其主要体现在短时间尺度上。

Driving Factors Analysis on Evolution of Water and Sediment at Datong Station

Datong hydrological station is the first key interface to enter the Yangtze estuary,thereby,the relationship between hydrology and sediment directly affects not only the spatial and temporal distribution of suspended sediment in the Yangtze estuary,but also the evolution of Yangtze delta.Further research on the driving factors of the relationship between water and sediment at Datong Station will be helpful to better understand the pattern of sediment transport in the Yangtze River basin,and to provide a scientific basis for an in-depth study on the evolution of the basin landscape and its response to human activities.Based on the mathematical statistics method,we qualitatively and quantitatively studied the effects of climate change and human activities on water and sediment characteristics at Datong Station from the precipitation and runoff change,water and soil engineering and so on.The results indicate that the climate change affects the change of water and sediment transport to a certain extent,and more reflects in the effect of long-term changes in sediment transport.However,the influence of large water conservancy and other human activities on sediment transport reflects mainly in the trend and time points of abrupt change.Human activities are the direct and main cause for water and sediment changes at Datong Station.