PLANNING FOR OPTIMAL WATER RESILIENCE IN CHENNAI CITY

Abstract

Globally, water-related issues in urban areas have intensified the scientific community's concern. Researchers and policymakers in urban development have recognized the importance of reinforcing resilience mechanisms in urban areas to cope with the disturbances caused due to environmental changes. Resilience originates from the Latin word 'resilio', meaning to bounce back or bounce forward. Resilience focuses not only on how the environment retaliates to disturbances associated with climatic changes but also on the capacity to withstand and restructure the growing demands and needs. Resilience has also helped to bridge the gap between disaster risk reduction and climate change adaptation by focusing on enhancing the performance of a system in the face of hazards rather than preventing those hazards from occurring. The Investigator has conducted an exhaustive literature study by reviewing literature thoroughly and observed that different authors investigated water-related issues in the urban system by employing different techniques in a piecemeal approach. However, the Investigator did not find even a single literature considering a holistic approach to minimize the problems pertaining to the urban water system. This study is novel in its approach by holistically analyzing water resilience by integrating the different sources of water supply and the disruptions related to urban flood, drought, groundwater exploitation, water pollution, sea-level rise and other water, sewerage infrastructure inefficacies. Furthermore, system dynamic techniques had not been employed to understand the dynamic function of the system by considering all the subsystems of the urban system aspects together. Analyzing the urban system as a whole is vital in this regard. The urban system is composed of physical, social, economic, infrastructure, institutional, ecological and environmental subsystems. These subsystems are further divided into different sub-subsystems or entities depending on the available information and the level of modelling required. The entities of all the subsystems are interlinked and interdependent yet keep on interacting with each other at different levels and functions as a whole. An in-depth assessment of urban settlements, including controlling parameters and their inter-relationship, is required for such an endeavour with the help of modelling techniques. Having this in mind, the Investigator has chosen Chennai city, one of India's prospective and prominent cities, to take up this investigation by considering all aforesaid aspects and evolving plausible policy planning guidelines for minimizing backwash effects of water-related issues in the system. Every other year, the city has been experiencing recurring droughts and floods. The drastic climate change resulted in a severe setback during heavy rainfall, leading to urban floods, and associated socio-economic and environmental problems. The recovery from this ill effect takes a minimum of two years to come back to the original situation. By that end, drought occurs, causing severe water scarcity even for domestic purposes. This creates socio-economic schisms in the system that paved the way for distress among the people and unhealthy situations in the entire system’s function. In this present investigation, an attempt has been made to evolve a set of plausible policy planning guidelines and make recommendations for optimal water resilience in Chennai City, by considering it as a system. It has been observed that the lack of a comprehensive plan and integrated approach hindered the system's resilience. Therefore, the Investigator has explored and analysed the available literature and data from the secondary sources and then has carried out a thorough grassroots-level investigation by conducting primary surveys at the household level, to understand the crucial control parameters, which influence the function of the system. Further, by considering the important control parameters of various subsystems of the system, System Dynamic model towards optimal water resilience has been developed. Thereafter, the evolved model is validated and used for forecasting in 2041 A.D. The functions of the system under various alternative conditions over a period of time have been examined using simulation techniques to arrive at alternative policy decisions in the forecaster year model. Subsequently, the best policy scenario has been identified based on the results of various policy scenarios tested in the model. Finally, a set of policy planning guidelines has been prepared by five years phase-wise, and the recommendations are made to achieve optimal water resilience in the study area.