This paper aims to identify the groundwater-potential zones in coastal zones of the Cuddalore district by integrating remote sensing, Geographic Information System (GIS), and Analytical Hierarchy Process (AHP) techniques. The thematic layers such as geomorphology, landuse/land cover, lineament density, geology, soil, drainage density, rainfall, and slope are considered for the identification of groundwater-potential zones. The groundwater-potential zones are categorized into five zones as ‘very good’, ‘good’, ‘moderate’, ‘poor’, and ‘very poor’. From the study, it is observed that the rainwater/surface water infiltration to the aquifer is high in the eastern region due to flat topography, and thus, these zones possess ‘very good’ and ‘good’ groundwater-potential zones. The groundwater potential in the central region of the study area possesses moderate infiltration capacity, which is suitable for agricultural practices. Moreover, it is also observed that the groundwater potential is ‘poor’ and ‘very poor’ in the northwest region due to steep slopes in which suitable recharge structures should be constructed in these zones to harvest the rainwater. Eventually, the obtained results are validated with existing bore wells in the study area, and it reveals that a GIS-based integrated method is an effective tool for the exploration of groundwater resources with high accuracy.

Lake ecosystems provide vital services, but face escalating threats from synthetic microplastic (MP) pollution driven by human activities, necessitating urgent action. This study investigates MP contamination in Dharapadavedu Lake, Tamil Nadu, India, characterizing its presence and distribution. MPs in water and sediment were assessed using NOAA's standardized protocol. The results indicate that mean concentration of MPs in lakeshore sediment and water was 2.46 ± 1.06 particles/kg and 1.26 ± 0.88 particles/L, respectively. Significantly, medium-sized MPs (500–1,000 μm) were most abundant, comprising predominantly white, red, and green colors with fragments and fiber morphotypes. Attenuated total reflection Fourier transform infrared spectroscopy revealed valuable insights into the polymer composition of MPs in the lake, identifying four primary types: nylon (polyamide), high-density polyethylene, low-density polyethylene, and polypropylene. Pollution load index data reveals that MP pollution levels of 2.26 in sediment and 1.46 in water indicate a moderate to high level of risk. These findings reveal that the repercussions of recreational activities, anthropogenic activities, and fishing practices around the lake contributed to the accumulation of MPs in the lake. This study fills a research gap by investigating MP pollution in Dharapadavedu Lake for the first time, establishing a baseline contamination estimate.

Groundwater is an essential source for household, irrigation and industry needs. The amount of groundwater and its quality are rapidly declining because of urbanization and industrialization. Groundwater resources in hard rock regions should be handled properly to maximize their utilization. This work aims to demarcate the Groundwater Potential Zones (GWPZ) in a part of the Palar River Basin (Ponnai sub-basin) by combining Remote Sensing (RS), Geographic Information System (GIS) and Fuzzy-Analytical Hierarchy Process (FAHP). The factors which influence the groundwater like geology, land use/land cover (LULC), geomorphology, slope, soil, rainfall, lineament density (LD), drainage density (DD), normalized difference vegetation index (NDVI), topographic wetness index (TWI) and topographic position index (TPI) are considered for mapping of GWPZ. The weightage is allocated to these parameters on the basis of the FAHP technique and the obtained groundwater potential map was classified as, very poor (13.5%), poor (21.76%), moderate (31.5%), good (20.66%) and very good (8.54%). The GWPZ map was validated with the actual well yield of the Ponnai sub-basin. The research work will serve as a guideline for the effective use of groundwater and long-term sustainable management of the aquifer in the Ponnai sub-basin.