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The extent of impervious cover in a watershed has been linked to the quality of an urban aquatic environment The Kyeongan watershed in South Korea was investigated to evaluate the relationship between the total impervious area (TIA) and the aquatic ecosystem of the watershed, including water quality and aquatic life using a relatively high-resolution (0.4m) image. The TIA was found to be approximately 12% of the watershed, which indicates that the quality of its environment was being adversely affected by it. For water quality, Pearson correlation analyses showed that all water quality parameters studied were found to be positively correlated with TIA atp < 0.01, except for nitrate (NO3~). In addition, the zone with a higher TIA was found to have worse water quality. Some water quality parameters, such as nitrite (NO2"), total phosphorus, and phosphate (PO4^~) were highly affected by discharges from wastewater treatment plants. Water quality data suggest that TIA could be used to predict the water quality of streams. For ecological parameters, the diatom index for organic pollution and trophic diatom index were found to be highly correlated with TIA, whereas physical habitat and benthic macroinvertebrates were pooriy correlated with TIA, However, the results indicate that the extent of impervious cover can be a useful indicator for predicting the status of specific ecosystem of streams. Water Environ. Res., 84, 635 (2012).

2014): Wet weather discharge characteristics of phosphorus and management implications in a mixed land-use watershed, Desalination and Water Treatment, A B S T R A C TThe diffuse phosphorus (P) load to receiving waters has been of great concern because it is considered the main cause of eutrophication and algal bloom in natural waters. For establishing effective P control strategy, it is the important first step to obtain information on characteristics of diffuse source of P and its discharge behavior during storm events. In this study, wet and dry sampling collection were performed to measure concentrations of P in different types (particulate, dissolved, and soluble reactive P for waters and adsorbed, nonapatite, apatite, and residual P for soil/sediment) in storm water runoff and soil/sediment on the catchment surface from different land uses. The results showed that urban land uses can be the most significant contributor to diffuse P loading because of the high concentration of P in the storm water run-off. Despite minimal wet discharge concentration of P observed, agricultural land-use can be a potentially important P source due to the relatively greater P content in agricultural soil. In addition, it was found that forest land use may discharge significant amount of P during storms unless soil erosion is properly controlled particularly in a large-scale storm. The results also suggested useful P management implications for different land uses. That is, urban site showed a strong first flush phenomenon, implying that first flush enhanced control should be a cost-effective strategy. Agricultural site revealed seasonal first flush of P, suggesting that management actions can be focused more on earlier season that has greater P discharge concentration. In addition, controlling fine particles should be very important because smaller particles contain greater amount of readily bioavailable P.

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