We study a tropical river in South-East Sumatra, where land drainage in the coastal zone has resulted in subsidence and increased flooding risks, exacerbated by sea tides. The novelty of this research is in determining the effect of tide on the lowland drainage system for forestry in a coastal tropical region and the impact of river cleaning on flood management. Five monitoring stations were set up along the Lebong Hitam river and its primary channels to observe flow characteristics, water level, and bathymetry. The results show how the tide effects water level in the river and the adjacent drainage area with Eucalyptus plantations. Cleaning of the river had a significant effect on each station and increased the discharge and velocity by more than five times and reduced the water depth by more than 40%. In light of this research, it can be concluded that the cleaning up process improves flood risk management by decreasing the water level and increasing the discharge and velocity at each of the upstream stations. The cleaning did not have a significant effect on downstream sections of the river where sea levels control the water level in the river to a large extent. The work provides an analysis of tidal river and provides recommendations for current and future drainage and water management.

中文翻译：

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河流清理对苏门答腊东南部低地排水的影响

我们研究了苏门答腊岛东南部的一条热带河流，该河流沿海地区的陆地排水导致了下沉，增加了洪水风险，而海潮又加剧了这一风险。这项研究的新颖之处在于确定潮汐对沿海热带地区林业低地排水系统的影响以及河流清理对洪水管理的影响。沿着 Lebong Hitam 河及其主要河道设立了五个监测站，以观测水流特征、水位和水深测量。结果显示了潮汐如何影响河流和邻近的桉树种植园流域的水位。河道清理对各站效果显着，流量和流速增加了5倍以上，水深减少了40%以上。根据这项研究，可以得出结论，清理过程通过降低水位并增加每个上游站的流量和流速来改善洪水风险管理。此次清理对河流下游河段影响不大，因为海平面在很大程度上控制了河流水位。这项工作对潮汐河进行了分析，并为当前和未来的排水和水管理提供了建议。