Characterisation of the benefit function of basin water allocation using a sigmoid-type S-curve logistic equation

• Published in: AQUA-WATER INFRASTRUCTURE ECOSYSTEMS AND SOCIETY
• Main Authors: Ishak, Ahmad Fakhri; Lee, Wei Koon; Lim, Foo Hoat
• Format: Article; Early Access
• Language: English
• Published: IWA PUBLISHING 2024
• Subjects: Engineering; Water Resources
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001195723700001
• ISSN: 2709-8028; 2709-8036
• DOI: 10.2166/aqua.2024.075

As water allocation (WA) is reduced due to water scarcity in a river basin, the benefit function for the domestic water users and the economic sectors declines accordingly. Using the sigmoid-type equation, which is ubiquitous in natural and man-made systems, this study shows that the S-curve behaviour can be seen in a broad range of basin WA scenarios. A questionnaire survey reveals that progressive water supply cutback results in a mild initial hassle but builds up to an elaborate inconvenience and subsequently a diminished shock to the water users. The economic benefit of water consumption based on 8-year data of states in Malaysia shows evidence of the S-curve characteristics where lesser developed states tend to benefit more as water consumption increases. The model allows the sectorial benefit (and impact) level to be approximated as a function of basin water availability. The mathematical quantification, in lieu of qualitative descriptors, is useful as an integral component in water prioritisation and WA decision-making to provide an empirical assessment of optimum basin-wide benefit.