Spatio-Temporal assessment of waterbodies for sustainable sub-urban planning and development – a geo-informatics approach

Abstract

World Population is expected to be 67% by the year 2050 in the urban areas, with the most rapid levels of urbanization and industrialization taking place in developing countries. Due to the rapid urban and sub-urban growth, most industries and industrial colonies are developed in the lake catchment and polluting the lakes. Hence, it is an urgent need to assess the lake catchment using geospatial tools for their sustainability. The present study's main aim is to assess surface water bodies' status using multi-dated remote sensing data for sustainable urban planning. The Kolavai Lake of the Chennai City Suburban has been taken as a study area, where water degradation is existing by the urbanization process. Due to the increasing anthropogenic activities and the natural process in the catchment of the Kolavai lake is under ecological pressure, losing its area, perimeter, and carrying capacity. Siltation from the run-off, discharging of pollutants from the industries, and dumping of municipal waste in the lake, the turbidity in the lake water is increasing daily, leading to lake water degradation. The physical and anthropogenic activities have been studied using Level-II land use/land cover (LULC) classification through multi-dated satellite data. It is observed from the LULC change detection analysis, about 53% of the catchment is occupied by the settlement and industries. The chemical and biological studies have been analyzed through lake water sample analysis. About 27 water sample locations have been chosen and samples were collected on a seasonal basis. The water samples were analyzed and the Water Quality Index (WQI) has been calculated to study the suitability of the lake water. The Water Quality Index (WQI) showed higher values in TDS, NO3, CO3, Mg, Cl, SO4, BOD, COD, and Fl. The water quality of Kolavai Lake was found unsuitable for drinking because WQI values exceed 100. By studying the physical, anthropogenic, and chemical parameters of the lake, a suitable recommendation has been given for the sustainable development of the lake by controlling the catchment area activities. Further, the study concludes that the government and non-governmental agencies to be taken into comprehensive ecological auditing and continuous monitoring of land use/land cover practices that will promote awareness among the stakeholders in a transparent way for sustainable usage of lake water.