|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1999 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1998 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Owing to overflows from combined sewer pipe systems, water quality of receiving waters, including urban rivers, in Japan, has become worse year by year. Therefore, appropriate counter-measures that can mitigate the overflows must be developed promptly. In order to achieve this, a practical distributed simulation model of water quality and storm water runoff is investigated, which can simulate precisely both open-channel and surcharged flows and a temporal and spatial variation of runoff-water quality in the pipe systems.
In this research, first PWRI Model, which is a lumped simulation model and was developed by the Public Works Research Institute, Japan, was transformed into a distributed simulation model. Second, PWRI Model was combined with LATERAL Model : these distributed models can simulate precisely storm water runoff with surcharge and a temporal and spatial variation of runoff-water quality in combined sewer pipe systems ; the models can be employed to evaluate the efficiency of various counter-measures that are designed to reduce CSOs and installed in the sewer pipe systems. Finally, the models were applied to a real urban drainage basin, and the adaptability of the models was investigated on the basis of the comparisons of observed and simulated runoff results. As a result, the following were pointed out (1) the agreement between the observed and simulated results, at this stage, is not necessarily adequate throughout the comparisons ; (2) the simulation model can reproduce well the runoff characteristics of pollutants influenced by flow regulations ; (3) the simulation model can be used to examine the efficiency of counter-measures mitigating CSOs.