ABSTRACT

A combination of discrete sampling using autosamplers triggered by area-velocity metres and continuous water quality monitoring using YSI datasondes enabled us to evaluate the dynamics of both stormwater runoff and dry weather water quality associated with an urban park and WSUD treatment train in Singapore. The WSUD treatment train consisted of a raingarden and sedimentation ponds. A first flush phenomenon was observed for total suspended solids (TSS) in three of four discrete-sampled events, but there was a less pronounced first flush characteristic for nutrients. Mean TN concentrations associated with runoff from the park (upstream of the WSUD treatment train) were in the range that would be associated with eutrophic conditions, while mean TP levels were in the mesotrophic/eutrophic boundary range. The raingarden reduced nutrient and TSS levels by 7–62% and loads by 65–93%, although nitrate levels were higher in the effluent compared to the influent. The sedimentation ponds successfully reduced sediment levels by 56%, based on continuous turbidity measurements. The dissolved oxygen levels in the sedimentation ponds were lower during drought periods, which has implications for aquatic organisms. The WSUD treatment train generally improved runoff quality from the park and such features can be easily integrated into the park design.

摘要

使用面积速度计触发的自动采样器进行离散采样，并使用 YSI 数据探空仪进行连续水质监测，这使我们能够评估与新加坡城市公园和 WSUD 处理列车相关的雨水径流和干旱天气水质的动态。WSUD 处理系统包括雨水花园和沉淀池。在四个离散采样事件中的三个中观察到总悬浮固体 (TSS) 的首次冲洗现象，但营养物的首次冲洗特征不太明显。与公园（WSUD 处理列车上游）径流相关的平均 TN 浓度处于与富营养化条件相关的范围内，而平均 TP 水平处于中营养/富营养化边界范围内。雨水花园将养分和 TSS 水平降低了 7-62%，将负荷降低了 65-93%，尽管与进水相比，出水的硝酸盐水平更高。根据连续的浊度测量，沉淀池成功地将沉积物水平降低了 56%。在干旱时期沉淀池中的溶解氧水平较低，这对水生生物有影响。WSUD 处理系统总体上改善了公园的径流质量，并且这些功能可以很容易地集成到公园设计中。这对水生生物有影响。WSUD 处理系统总体上改善了公园的径流质量，并且这些功能可以很容易地集成到公园设计中。这对水生生物有影响。WSUD 处理系统总体上改善了公园的径流质量，并且这些功能可以很容易地集成到公园设计中。