We sampled the Klang estuary during the inter-monsoon and northeast monsoon period (July–Nov 2011, Oct–Nov 2012), which coincided with higher rainfall and elevated Klang River flow. The increased freshwater inflow into the estuary resulted in water column stratification that was observed during both sampling periods. Dissolved oxygen (DO) dropped below 63 μM, and hypoxia was observed. Elevated river flow also transported dissolved inorganic nutrients, chlorophyll a and bacteria to the estuary. However, bacterial production did not correlate with DO concentration in this study. As hypoxia was probably not due to in situ heterotrophic processes, deoxygenated waters were probably from upstream. We surmised this as DO correlated with salinity (R² = 0.664, df = 86, p < 0.001). DO also decreased with increasing flushing time (R² = 0.556, df = 11, p < 0.01), suggesting that when flushing time (> 6.7 h), hypoxia could occur at the Klang estuary. Here, we presented a model that related riverine flow rate to the post-heavy rainfall hypoxia that explicated the episodic hypoxia at Klang estuary. As Klang estuary supports aquaculture and cockle culture, our results could help protect the aquaculture and cockle culture industry here.

我们在季风间期和东北季风期间（2011 年 7 月至 11 月，2012 年 10 月至 11 月）对巴生河口进行了采样，此时降雨量增加，巴生河流量增加。流入河口的淡水增加导致两个采样期间观察到的水柱分层。溶解氧 (DO) 降至 63 μM 以下，观察到缺氧。河水流量升高还将溶解的无机营养物、叶绿素a和细菌输送到河口。然而，在本研究中，细菌产量与 DO 浓度无关。由于缺氧可能不是由于原位异养过程造成的，脱氧水可能来自上游。我们推测这是 DO 与盐度相关（ R ² = 0.664，df = 86， p < 0.001）。 DO 也随着冲水时间的增加而减少（ R ² = 0.556，df = 11， p < 0.01），这表明当冲水时间（> 6.7 h）时，巴生河口可能会出现缺氧。在这里，我们提出了一个将河流流量与大雨后缺氧联系起来的模型，该模型解释了巴生河口的间歇性缺氧。由于巴生河口支持水产养殖和鸟蛤养殖，我们的研究结果可以帮助保护这里的水产养殖和鸟蛤养殖业。