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监测和预报悬浮泥沙浓度的沿程分布和时间变化,无论是对于河流水利工程还是河流生态和环境保护都具有重要意义。卫星遥感反演同步性好、速度快、周期短,可以实时和全面地观测大尺度悬浮泥沙分布。旨在建立基于中分辨率成像光谱仪(MODIS)影像的长江中游河段悬浮泥沙浓度反演模型,并利用建立的模型反演2002～2009年长江中游河段丰水期的悬浮泥沙浓度,分析其在时间和空间上的变化特征。研究揭示,MODIS Terra影像红波段与悬浮泥沙浓度具有显著的相关性(R2=0.877,n=125,RMSE=40.57mg/L),可以用于长江中游丰水期悬浮泥沙浓度的反演。长江三峡工程经历三次蓄水,坝下游宜昌至汉口段悬浮泥沙含量显著减少,荆江河段、洞庭湖及城陵矶至武汉江段下降最为显著。洞庭湖来水来沙是长江中游城陵矶以下江段主要的悬浮泥沙来源之一,从预测结果可知,洞庭湖来水在城陵矶汇入长江后与江水混合以至形成数十公里的混合带,至洪湖以下江段逐渐混合均匀。
Monitoring and forecasting the distribution of sediment concentration along the time course and the time variation are of great significance both for river water conservancy projects and river ecological and environmental protection. Synchronous satellite remote sensing with good synchronization, fast, short cycle, real-time and comprehensive observation of large-scale suspended sediment distribution. The purpose of this study is to establish an inversion model of suspended sediment concentration in the middle reaches of the Yangtze River based on medium resolution imaging spectrometer (MODIS) images. The suspended sediment concentration of the Yangtze River reaches during the wet season is retrieved by using the established model. Analyze its changing characteristics in time and space. The study revealed that there is a significant correlation between the MODIS Terra image and the suspended sediment concentration (R2 = 0.877, n = 125, RMSE = 40.57 mg / L), which can be used for the inversion of suspended sediment concentration during the wet season in the middle reaches of the Yangtze River . The Yangtze River Three Gorges Project experienced three impoundments, and the suspended sediment content of Yichang-Hankou sections downstream of the dam decreased significantly. The decline of Jingjiang reach, Dongting Lake and Chenglingji-Wuhan segment was the most significant. Water and sand from Dongting Lake is one of the main suspended sediment sources in the lower reaches of Chenglingji in the middle reaches of the Yangtze River. According to the forecast results, the incoming water of Dongting Lake flows into the Yangtze River and flows into the Yangtze River to form tens of kilometers Mixing zone, to Honghu following gradual mixing well.