This study assesses the changes in land use/land cover (LULC) and land surface temperature (LST) to identify their impacts from 2000 to 2020 along the coast of Kanyakumari district, India using remote sensing techniques. Landsat images are used to estimate the LULC changes and the MODIS data for LST. The Maximum Likelihood Classification (MLC) method is used, and the LULC is classified into six categories: Agriculture Land, Barren Land, Salt Pan, Sandy Beach, Settlement, and Waterbody. Within the two decades of the present change detection study, upheave in the Settlement area of 49.89% is noticed, and the Agriculture Land is exploited by 20.09%. Salt Pan emits a high LST of 31.57 ℃, and the Waterbodies are noticed with a low LST of 28.9 ℃. However, the overall rate of LST decreased by 0.56 ℃ during this period. This study will help policymakers make appropriate planning and management to overcome the impact of LULC and LST in the forthcoming years.

This study explains the multi-decadal shoreline changes along the coast of Kanyakumari from 1980 to 2020. The shorelines are extracted from the Landsat images to estimate the shoreline dynamics and future predictions using Digital Shoreline Analysis System (DSAS). By the estimation of End Point Rate (EPR) and Linear Regression Rate (LRR), it is quantified that the maximum erosion is 5.01 m/yr (EPR) and 6.13 m/yr (LRR) consistently with the maximum accretion of 3.77 m/yr (EPR) and 3.11 m/yr (LRR) along the entire coastal stretch of 77 km. The future shoreline predicted using the Kalman filter forecasted that Inayam, Periyakattuthurai and Kodimunai are highly prone to erosion with a shift of 170 m, 157 m and 145 m by 2030 and 194 m, 182 m and 165 m by 2040 towards the land. Also, the western coast is highly prone to erosion and it is predicted that certain villages are prone to loss of economy and livelihood. The outcome of this study may guide the coastal researchers to understand the evolution and decision-makers to evolve with alternative sustainable management plans in the future.

The study aims to assess the nitrate and fluoride concentration in groundwater and its adverse effects on human health. In 2019, 42 groundwater samples were collected from various bore wells within the western Noyyal basin, India. Sodium and chloride are the dominant cation and anion, respectively. The nitrate concentration in groundwater samples varies from 2 to 89 mg/L, of which 33.33% are above the permissible limit of 45 mg/L for drinking water. The fluoride concentration ranges from 0.2 to 2.4 mg/L, with 28.57% of the samples exceeding the safe value of 1.5 mg/L for drinking water. Correlation plots demonstrate that the potential of hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), Na⁺ and HCO₃^- are positively correlated with F^-, whereas Ca²⁺ is negatively correlated. Mixed Ca–Mg–Cl is the most common water type in the investigated region. The Gibbs diagram demonstrates that the interaction between rock and water impacts the groundwater chemistry. Using the method of the United States Environmental Production Agency (USEPA), this study assesses the non-carcinogenic health risk posed by nitrate and fluoride in different age groups (infants, children, and adults). The values of total hazard index (THI) vary from 0.59 to 10.07 (mean = 4.76) for infants, 0.36 to 6.23 (mean = 2.95) for children, and 0.19 to 3.32 (mean = 1.57) for adults. Furthermore, 97.62%, 92.86%, and 73.81% of the samples surpass the recommended limit (THI = 1) for infants, children, and adults, respectively. Thus, the health risk assessment (HRA) indicates that infants and children are more susceptible to noncarcinogenic health hazards than adults. The THI spatial variation map shows that central and southern regions of the study area have been identified as high health risk areas (THI >3.0) for all age groups.

This research aims to assess the sensitive coastal zones by analyzing the shoreline changes such as accretion and erosion in the eastern coastal part of Ramanathapuram District, Tamil Nadu, India. The study focused on Mandapam, Pirappanvalsai, Enmanamcondam, Nagachi, Terbogi, Athyuthu, Chitrakkottai, Pathengal, Attangarai, Alagankulam, and Devipattinam villages. Some of these areas are distinguished as highly sensitive ecological zone. The erosion of an area leads to irreplaceable disturbances to nature. Hence, erosion and accretion studies are top priorities when studying the coastal area. In addition to GIS technology, which has been widely used in the past 20 years, the End Point Rate (EPR) and Linear Regression Rate (LRR) analyses were conducted to better understand the shoreline changes. The stability of the coastal region was analyzed by observing the slope variations of the beach during the profile survey. In the study, we analyzed that the Quaternary deposits of sand are the dominant geological feature of the study area. Coral reefs and salt pans are highly distributed along the coastal stretch. The coast of Mandapam village has been detected as a highly sensitive region, with an average erosion rate of −3.1 m/yr and an average accretion rate of 1.22 m/yr, resulting in high erosion and low accretion. The coast is a steep coast with an average slope angle of 0.24^°. This study provides insight into sustainable coastal zone management.