In response to rapid development and high demand for electricity, Cambodia has planned to build more hydropower dams. As a result, there are significant concerns for the changes in seasonal flow regimes which will result in degrading fisheries and biodiversity downstream. In this paper, we assess how a multipurpose dam affects downstream flows. To predict the magnitude of flow changes, flows which were simulated using SWAT (Soil and Water Assessment Tool) and other necessary data were computed into HEC-ResSim (Reservoir Simulation) models to simulate regulated flow from the dam. Downstream flows under three different operation scenarios (full-level, low-level, and seasonal variation) were modeled to compare with the baseline flows. For low-level and seasonal variation operation scenarios of Stung Sen dam, daily and seasonal flows saw a significant change. There would be an average increase of 42% in dry season flow and an average decrease of 46% in wet season flow, with the corresponding standard deviation of 22% and 19%, respectively, at the outlet of Stung Sen Basin, resulting from an operation to maximize energy production. The natural river flow in this river would be significantly changed due to this dam construction.

为响应快速发展和对电力的高需求，柬埔寨计划建造更多的水电大坝。结果，人们对季节性流量制度的变化十分关注，这将导致下游渔业和生物多样性的退化。在本文中，我们评估了多功能水坝如何影响下游流量。为了预测流量变化的幅度，将使用SWAT（土壤和水评估工具）模拟的流量以及其他必要数据计算到HEC-ResSim（水库模拟）模型中，以模拟来自大坝的调节流量。对三种不同操作方案（全水平，低水平和季节性变化）下的下游流量进行了建模，以与基准流量进行比较。对于上森大坝的低水平和季节性变化的运行方案，每日和季节性流量发生了重大变化。斯通森盆地出口处的旱季流量平均增加42％，雨季流量平均减少46％，相应的标准偏差分别为22％和19％。运行以最大化能源生产。由于大坝的建设，这条河的自然河流量将发生很大变化。