Mathematical model of water quality rehabilitation with rainwater utilisation: a case study at Haigang

This paper presents a mathematical model of water quality rehabilitation by utilising rainwater, which is separated into initial polluted rainwater and later unpolluted rainwater. The planned Haigang city, belonging to Shanghai metropolis in China, is taken as a case example. An analysis is made on how to utilise rainwater and appraise its function in a water quality rehabilitation scheme. It is demonstrated that this method can significantly reduce both project investment and operation costs. Moreover, appropriate drainage plan scheme is presented to address the initial polluted rainwater problem. Thus, the conflict between drainage and rainwater utilisation can be resolved appropriately.