Optimal Design of Low Impact Development Practices in Response to Climate Change
Urban drainage systems are generally designed based on the analysis of historical hydrologic variables, especially rainfall. Hydrologic analysis, however, has been shown to be affected by climate change. In response to the modified pattern of rainfall, stormwater management practices, such as Low Impact Developments (LIDs), need to be applied to successfully respond to the possible future climatic conditions, while meeting the performance criteria based on the current state of the watershed. In this study, a simulation-optimization framework is proposed to find the optimal design of LIDs (type, location, and area) under climate change. Storm Water Management Model (SWMM) is utilized to simulate the rainfall-runoff process. This model is linked with a single-objective optimization routine formulated by Genetic Algorithm (GA) that minimizes runoff volume and the costs associated with the LIDs’ design. To investigate how climate change might affect the future watershed runoff, rainfall projections by several General Circulation Models (GCMs) are used. Change factor methodology is applied to downscale GCMs’ outputs. The framework is applied to the Velenjak watershed, located in the northeastern Tehran, Iran. Results show that the optimization algorithm provides optimal solutions for LIDs’ design under different extreme climate scenarios by allocating an average of 0.23% of the watershed area (20% of the maximum potential area considered for LIDs’ implementation), which results in a runoff volume reduction of up to 18%. The results also indicate that the optimal design of LIDs based on the current condition satisfies the watershed management goals and expectations in a future subjected to climate change impacts. Moreover, the results signify that the formulated multi-event optimization algorithm provides a unique solution meeting the objective functions for all considered climate scenarios at once.
Digital Object Identifier (DOI)
Published in Journal of Hydrology, Volume 580, 2020.
© 2019 Elsevier B.V. All rights reserved.
Ghodsi, S. H., Zahmatkesh, Z., Goharian, E., Kerachian, R., & Zhu, Z. (2020). Optimal design of low impact development practices in response to climate change. Journal of Hydrology, 580, 124266. https://doi.org/10.1016/j.jhydrol.2019.124266