Migrating Storms and Optimal Control of Urban Sewer Networks

Upaka Rathnayake

doi:10.3390/hydrology2040230

Abstract

Uniform storms are generally applied in most of the research on sewer systems. This is for modeling simplicity. However, in the real world, these conditions may not be applicable. It is very important to consider the migration behavior of storms not only in the design of combined sewers, but also in controlling them. Therefore, this research was carried out to improve Rathnayake and Tanyimboh’s optimal control algorithm for migrating storms. Promising results were found from the model improvement. Feasible solutions were obtained from the multi-objective optimization and, in addition, the role of on-line storage tanks was well placed.

Highlights

Uniform storms are generally applied in most of the research on sewer systems [1]
The overall peak discharge of a downstream migrating storm exceeds that of an upstream migrating storm [1,2,3,4]
The safety level is low compared to a uniform rainfall event, with equal directions for both wind and flow [1], and can cause combined sewer overflows (CSOs)

Summary

Introduction

Uniform storms are generally applied in most of the research on sewer systems [1]. This is for modeling simplicity. The safety level is low compared to a uniform rainfall event, with equal directions for both wind and flow [1], and can cause combined sewer overflows (CSOs) This notable difference has been excluded when considering the uniform rainfall conditions for the simulations for simplicity. SUDS try to reduce the storm water flow to the combined sewer networks during the stormy periods This is done by introducing natural infiltration techniques to infiltrate the majority of the storm water. Rathnayake and Tanyimboh [5,6,7,8] have presented an optimal control model for urban sewer systems considering the water quality effects in receiving water due to CSOs. that was for uniform storms. Rathnayake and Tanyimboh’s optimal control model [5,6,8] was improved with two different migrating storms, including migrating downstream and migrating upstream storms

Mathematical Formulations

Solution Technique

Case Study

Results and Discussion

Conclusions