Thesis (M. Eng.) - Asian Institute of Technology, 2022

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management

Rapid urbanization and population growth have increased around the world{u2019}s natural water resources more than ever. The changes in land use due to increased urbanization cause impervious surfaces leading to extreme to severe urban flooding and deterioration in water quality. The aforementioned issues can be dealt with or minimized by employing Nature Based Solutions (NBS). In recent decades, NBS have been adapted for urban drainage in developed countries, mostly having temperate climate while there is a need to develop similar sustainable measures for urban drainage in tropical regions as currently there are no guidelines for their implementation in tropical climate. In this study multi criteria decision analysis (MCDA) approach was utilized to identify the best site for NBS in Asian Institute of Technology (AIT), Thailand. Then PCSWMM software was used to develop a NBS model employing a Bioretention system. Moreover, a campus wide design was performed using a Climate Resilient Cities (CRC) Toolbox and utilizing different type of Low Impact Developments (LIDs) including bioretention system, rain garden, bio swales, green roofs, permeable pavements and urban forests. It was found that MCDA approach is a suitable approach to decide the best site for NBS implementation considering different aspects including economic, environmental and technical. The results strongly suggested that site-1 is a suitable alternative to implement NBS in AIT campus. It was found that bioretention system can reduce runoff volume by at least 14% and pollutants by at least 14-20 % respectively. Furthermore, it was revealed that a combination of different type of LIDs can provide reduction in pluvial flooding along with other benefits such as improved water quality and heat reduction. The present study will provide a guideline for site selection and development of the NBS model for urban water management in tropical climate. Moreover, it will provide a guideline to perform a campus wide design of NBS for AIT campus and a baseline to implement NBS projects in Thailand.