基于遥感的鄱阳湖丰水期悬浮泥沙数值模拟预测

Suspended Sediment Transport Modeling of Poyang Lake in the Wet Season Based on Remote Sensing Data

  • 摘要: 悬浮泥沙是湖泊水体的重要水质要素之一,是湖泊水生态系统重要影响因子。利用遥感提取的鄱阳湖底质类型数据,对各类型底质区域上泥沙模型参数进行敏感性分析,基于2011年实测的不同底质区上泥沙浓度数据率定得到空间上不一致的泥沙模型参数,从而建立鄱阳湖丰水期二维悬浮泥沙输运模型。利用该模型模拟预测2013年丰水期悬浮泥沙输移过程,实测泥沙数据验证表明,模拟悬浮泥沙均方根误差为19.8 mg/L,相关系数R2为0.78,该模型能够较好地进行悬浮泥沙模拟预测。对比模型模拟和遥感反演的悬浮泥沙空间分布,两者具有较好的空间一致性,进一步表明该模型能够可靠地模拟预测鄱阳湖悬浮泥沙的时空动态变化。本研究充分利用遥感数据辅助建立鄱阳湖泥沙输移模型,为湖泊水环境动态变化监测提供有力的技术方法支撑,为进一步进行鄱阳湖水环境动态变化的数值模拟预测研究提供基础。

     

    Abstract: Suspended sediment is one of the important factors of water quality and aquatic ecosystem for lakes. A two-dimensional sediment transport model of Poyang Lake was established in the wet season. The lake substrate data obtained from remote sensing image was used to perform parameter sensitivity analysis of the sediment transport model, and then the model parameters were calibrated based on the insitu measured sediment concentration in the area with different lake substrate type. The model was used to forecast the sediment transport of Poyang Lake during its high water period in 2013. Model validation showed the square root mean error is 19.8 mg/L and the R2 is 0.78 for the simulated sediment concentration, revealing a good performance of the model. Spatial distribution of sediment concentration from the model results and remote sensing images showed a satisfactory spatial consistence, further indicating the ability of the model to simulate the sediment transport of Poyang Lake. This study provides a reliable method to monitor the water environment dynamic of lakes and makes a foundation for further studying the water environment dynamic of Poyang Lake.

     

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