A Two‐Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

Abstract

Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue methodM/M/1→M/D/1to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total cost of construction and operation and overall sojourn time of stormwater. An improved genetic algorithm is redesigned to solve this complex nondeterministic problem, which incorporates with stochastic and fuzzy characteristics in whole drainage process. A numerical example in Shanghai illustrates how to implement the model, and comparisons with alternative algorithms show its performance in computational flexibility and efficiency. Discussions on sensitivity of four main parameters, that is, quantity of pump stations, drainage pipe diameter, rainstorm precipitation intensity, and confidence levels, are also presented to provide guidance for designing urban drainage system.

An ensemble risk assessment model for urban rainstorm disasters based on random forest and deep belief nets: a case study of Nanjing, China

“…Thus, there are extensive researches on the risk assessment model of URSD, such as mathematical statistics method, meteorological and hydrological model, and geographic information system. For instance, He and Hu (2017) discussed sensitivity of four main parameters of urban drainage system using improved genetic algorithm and two-stage queuing model; Xu et al (2018) proposed a comprehensive evaluation method of urban flood risk by combining urban flood inundation model, improved entropy method and k-means clustering algorithm. Based on Meteorological and hydrological model, some scholars established the latest rainstorm intensity formula and simulated the generation process of URSD (Wang et al 2017;Shao and Liu 2018).…”

Stationary analysis of infinite queueing system with two-stage network server

“…Many countries are suffering severe flood problems due to inadequate investment in their drainage system. Xinhua He and Wenfa Hu [9], investigated distribution feature of rainstorms and draining process and used a two-stage single queue method to model urban drainage system. Zhou et al [28], developed a two stage tandem queuing network and introduced a Markov arrival process to characterize the correlation of the demand in the business sector.…”

Using Multiple Index Comprehensive Method to Assess Urban Rainstorm Disaster Risk in Jiangsu Province, China

“…With the global climate change and the rapid developments of the urbanization, many cities are suffered extreme rainstorm events frequently [1][2][3][4]. According to EM-DAT and Munich RE disaster databases, about 15% of the worldwide population is under the threat of the rainstorm disasters, and flood losses account for 28% of total global disaster losses.…”