Predicting dam‐related downstream geomorphic response with widely available stream gauge data: A case study of the Godavari River Basin, India
Predicting dam‐related downstream geomorphic response with widely available stream gauge data: A case study of the Godavari River Basin, India
复制标题
利用广泛可用的流量计数据预测与大坝相关的下游地貌响应：印度戈达瓦里河流域的案例研究
DOI：
10.1111/sjtg.12323
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发表时间：
2020
影响因子：
2.2
通讯作者：
Kanae Shinjiro
中科院分区：
文献类型：
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作者：
Sanyal Joy;Dasgupta Priyanka;Kanae Shinjiro
与大坝相关的河床下游调整通常通过分析坝前和坝后期间泥沙供应和高流量事件的趋势进行研究。现有的预测模型所需的数据并不是在河规上测量的，这限制了这些工具的应用。我们利用广泛可用的测量记录推导了大坝前后的输沙径流事件（T*）和上游泥沙供应（S*）的频率，并通过调整现有模型预测了下游河床的变化。十个测量站在戈达瓦里河流域，印度，位于下游的大坝，被选为研究地点。每个站点的年度横截面调查验证了预测的大坝相关下游变化的准确性。在此基础上，建立了Godavari盆地T*/S*（自变量）与下游河床高程变化（因变量）之间的回归方程（R2= 0.75）。我们建议为较大的河流流域制定类似的地方经验方程。可以考虑大坝影响的大尺度降雨径流和泥沙输运过程模型，如土壤和水资源评估工具，可以与拟议的回归方程配对，以利用全球可用数据估计与大坝相关的下游侵蚀和沉积。
Dam‐related downstream adjustments of riverbeds are normally investigated by analysing the trend in sediment supply and high flow events during the pre‐ and post‐dam periods. The required data for existing predictive models is not measured at river gauges, which limits the application of these tools. We derived the frequency of sediment‐transporting streamflow events (T*) and upstream sediment supply (S*) in the pre‐ and post‐dam periods with widely available gauged records and predicted changes in the downstream riverbed by adapting an existing model. Ten gauging stations in the Godavari River Basin, India, located downstream of dams, were chosen as study sites. Annually surveyed cross‐sections at each site validated the accuracy of the predicted dam‐related downstream changes. Then, a regression equation (R2= 0.75) was established between T*/S* (independent variable) and changes in the downstream bed elevation (dependent variable) for the Godavari Basin. We recommended that similar local empirical equations be formulated for larger river basins. Models of large‐scale rainfall‐runoff and sediment transport processes that can account for the influence of dams, such as the Soil & Water Assessment Tool, can be paired with the proposed regression equation to estimate dam‐related downstream erosion and deposition with globally available data.