Faculty Publications
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Item Geospatial and Hydrogeochemical Insights for Monitoring Water Quality and Salinity in Coastal Regions of Southern Karnataka, India(Springer Science+Business Media, 2025) Suryawanshi, V.; Ramesh, H.; Nasar, T.Coastal areas face significant challenges due to the depletion of groundwater and seawater intrusion into freshwater aquifers. Additionally, insufficient monitoring of freshwater quality is a major concern for consumers. In Karnataka’s Dakshina Kannada district, groundwater is crucial for meeting the needs of the community, industry, and agriculture. This study investigates the impact of excessive use, human activities, and agricultural chemicals on groundwater quality, with a focus on the hydrogeochemistry of the Natravathi and Gurapura catchments. The study analyzed 32 groundwater samples collected seasonally from 2021 to 2022 for 18 physiochemical parameters. The Water Quality Index (WQI) was determined using factors such as pH, Dissolved Solids, Oxidatio Reduction Potentisl, Electrical Conductivity, Total Hardness, Total Dissolved Solids, Calcium, Chlorides, Potassium, and Sodium. WQI scores ranged from 0 to 52 post-monsoon and 0 to 42 pre-monsoon. An ArcGIS-based spatial distribution map was created to show temporal changes in groundwater quality. Post monsoon measurements showed significant cations ranging from 4.25 to 64.54 mg/l, calcium from 40 to 520 mg/l, chloride from 40 to 200 mg/l, and potassium from − 8.05 to 15.44 mg/l. Pre-monsoon measurements indicated sodium levels from 28 to 208 mg/l, calcium from 240 to 840 mg/l, chloride from 19.99 to 159.9 mg/l, and potassium from 0 to 61.79 mg/l. WQI results for the post-monsoon season showed 36% of sampling sites as excellent, 52% good, 8% poor, and 4% very poor, while pre-monsoon results indicated 13% excellent, 46% good, and 42% poor. The research reveals higher toxin concentrations in drinking water during pre monsoon period compared to post monsoon, with increased salinity in freshwater aquifers making the water unsuitable for consumption. © 2025 The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Assessment of hydropower potential in Nethravathi river basin using SWAT model(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2015) Babar, S.; Shobhita, M.P.; Ramesh, H.Hydropower plants have the advantage of producing renewable and clean power, the renewable and reliable energy source that serves national environmental and energy policy objectives. Therefore, the development of hydropower plant and improvements of water management have essential in contributing to sustainable growth and energy production in developing countries like India. The present study is concerned with the development of methodology and assessment of hydropower potential in the Nethravathi River basin with the help of Remote Sensing and GIS. The drainage area covers about 3190 km2 at Bantwal gauging point, and most of the land cover of the basin is dominated by forest. The basin was divided into six sub-basins based on hydrology and topography using GIS tools. The climate over the basin is coastal humid tropical and receives an average annual rainfall of about 4000 mm. sub-basin discharges were estimated using the Soil Conservation Services (SCS) curve number method. To ensure the total discharge from six sub-basins computed from SCS curve number method, the flows were routed and simulated at the gauging location using Soil and Water Assessment Tool (SWAT). SWAT model was calibrated for monthly time steps from 1998–2001, and validated for 2002–2003. Flow-duration curves (FDC) were generated for each sub-basin to assess the dependable yield. The results have shown a good agreement between observed and the simulated flows. The available discharge at 75%, 80% and 90% of time for each sub-basin were extracted from the FDC. This result were used to calculate the hydropower potential in all the six sub-basins at Q75, Q80 and Q90, by integrating thematic layers using ArcSWAT. © 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Assessment of soil erosion by RUSLE model using remote sensing and GIS - A case study of Nethravathi Basin(Elsevier B.V., 2016) Ganasri, B.P.; Ramesh, H.Soil erosion is a serious problem arising from agricultural intensification, land degradation and other anthropogenic activities. Assessment of soil erosion is useful in planning and conservation works in a watershed or basin. Modelling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. In the present study, the soil loss model, Revised Universal Soil Loss Equation (RUSLE) integrated with GIS has been used to estimate soil loss in the Nethravathi Basin located in the southwestern part of India. The Nethravathi Basin is a tropical coastal humid area having a drainage area of 3128 km2 up to the gauging station. The parameters of RUSLE model were estimated using remote sensing data and the erosion probability zones were determined using GIS. The estimated rainfall erosivity, soil erodibility, topographic and crop management factors range from 2948.16 to 4711.4 MJ/mm·ha? 1hr? 1/year, 0.10 to 0.44 t ha? 1·MJ? 1·mm? 1, 0 to 92,774 and 0 to 0.63 respectively. The results indicate that the estimated total annual potential soil loss of about 473,339 t/yr is comparable with the measured sediment of 441,870 t/yr during the water year 2002–2003. The predicted soil erosion rate due to increase in agricultural area is about 14,673.5 t/yr. The probability zone map has been derived by the weighted overlay index method indicate that the major portion of the study area comes under low probability zone and only a small portion comes under high and very high probability zone. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Nethravathi Basin. © 2015 China University of Geosciences (Beijing) and Peking UniversityItem Geo-statistical analysis of groundwater quality in an unconfined aquifer of Nethravathi and Gurpur river confluence, India(Springer Science and Business Media Deutschland GmbH, 2018) Sylus, K.J.; Ramesh, H.The groundwater quality plays a vital role in domestic, industrial and agricultural water supply. However, seawater intrusion was one of the major problems occur worldwide in the coastal aquifers due to excessive pumping of fresh groundwater. Thus, groundwater gets contaminated due to seawater intrusion, disposal of industrial waste etc. Due to this reason, it becomes necessary for regular monitoring of groundwater quality, in order to take proper measures for avoiding and reducing contamination. Hence, the present study was aimed to assess water quality in Nethravathi and Gurpur river confluence, located on the west coast of India. Groundwater samples were collected for the month of January 2013–May 2017, which was further analysed in the laboratory as per Bureau of Indian Standards (BIS) and World Health Organisation (WHO) standards. The water quality parameters considered for analysis are Potential Hydrogen (pH), Sodium (Na), Potassium (K), Electrical conductivity (EC), Chloride (Cl), Total Dissolved Solids (TDS), Calcium (Ca), Magnesium (Mg), Total Hardness (TH) and Bicarbonate (HCO3). The results of these parameters were further mapped using Geographical Information System (GIS) to visualize spatial distribution. The geo-statistical analysis was also carried out using SPSS tool to know the correlation of these parameters. The regression analysis was carried out with Factor of sea to the chemical parameters such as Bicarbonate (HCO3), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Calcium (Ca), Magnesium (Mg) and Total Hardness (TH). The significant groundwater quality chemical parameters were found by correlation analysis. The significant groundwater quality chemical parameters were further given as input for mapping, prediction and modelling of groundwater quality. The prediction of significant parameters carried out using the monthly groundwater quality data for the year 2013 and 2014. The result of spatial mapping and statistical analysis provides the spatial and temporal variation of groundwater quality in the study area. The results showed that only Panganimuguru and Kunjatbail region is affected by seawater. The modelling results of Cl and TDS shows the spatial occurrence of contamination in the study area of Netravathi and Gurpur river confluence at the various time period. Further, the results of the modelling also show that the contamination occurs up to a distance of 519 m towards the freshwater zone of the study area. © 2018, Springer International Publishing AG, part of Springer Nature.