Spatial modelling of seaweed farming potential areas in Chengalpattu district using a Fuzzy AHP-GIS framework

Abstract

Seaweeds, with their diverse applications in food, energy, medicine and the chemical industry, hold immense potential as a renewable resource. However, the escalating demand for seaweed products has surpassed the sustainable yield from natural sources. This supply-demand gap necessitates the exploration and expansion of seaweed cultivation. While marine ecosystems currently dominate seaweed farming practices, investigating alternative cultivation environments is essential, as brackishwater offers an untapped opportunity for the sustainable production of this valuable resource. This study aims to systematically identify and assess potential areas suitable for seaweed farming in the Chengalpattu district brackishwater ecosystem using the Fuzzy Analytic Hierarchy Process (FAHP) in conjunction with geospatial techniques. FAHP combines AHP with fuzzy logic to better handle uncertainty and subjectivity in decision-making. Twenty-two representative locations along the coast in the brackishwater ecosystem were identified, and samples were collected and assessed at monthly intervals. This comprehensive study involved a meticulous evaluation of several key criteria viz., water quality, environmental factors, resource accessibility and relevant constraints. To facilitate a nuanced and spatially explicit analysis, each criterion was further sub-classified and systematically mapped using ArcGIS. Results revealed a total of 141.56 hectares as potential areas for seaweed farming, with 91.93 hectares classified as highly suitable and 49.63 hectares as moderately suitable. The findings contribute to the advancement of sustainable aquaculture practices by promoting the cultivation of seaweed in underutilised brackishwater environments. This strategic approach not only caters to the escalating market demand for seaweed but also cultivates economic prospects and livelihood enhancement for coastal communities.