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Tasuku Yoshioka, Department of Urban Engineering, wins JSWE-KURITA Best Presentation Award

 

Tasuku Yoshioka, Department of Urban Engineering, wins JSWE-KURITA Best Presentation Award. Awards are given to the research presentations conducted by graduate students in master's programs so as to increase research motivation.

 

(Japan Society on Water Environment website:http://www.jswe.or.jp/eng/awards/annualconference/index.html)

 

        


“Water quality modeling and cost-benefit analysis at for Edo Castle Outer Moat”

The Edo Castle is placed in central Tokyo and its Outer Moat provides precious water environment in the urban area. The water sources are very limited to the precipitation and the combined sewer overflow (CSO), therefore, the hydraulic retention time (HRT) becomes very long (tens of days), resulting in the bad water quality. Especially in summer, serious algal bloom is observed, and it causes problems of view and smell. To develop the effective countermeasures for water quality improvement, the estimation of CSO inflow and the water quality prediction by means of runoff and algal growth models were conducted. Besides, the actual water level and water quality were regularly measured through field surveys for checking the models. Using the models, it was proved that the combination of CSO prevention and reclaimed water introduction (4,653m3day-1) could prevent the algal bloom. The cost for the countermeasure was estimated at 390 million yenyear-1. The benefit was evaluated by CVM (Contingent Valuation Method) and estimated at 750 million yenyear-1. Finally, comparing cost and benefit, feasibility of the countermeasures was shown.


 

<Comments>
I am very honored to recieve this award. I am most grateful to my supevisors for giving me advice. I will make use of this experience in my work.