Faculty Publications
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Item Estimation of Reservoir Storage Using Artificial Neural Network (ANN)(Springer Nature, 2018) Satish, P.; Ramesh, H.The rapid growth in population increases water demand thus resulting in scarcity of water which is due to improper management rather than lack of resources. Reservoir is the most important source for surface water. So, reservoir storage plays a crucial role in efficient reservoir management. Artificial neural network (ANN) is capable of simulating reservoir storage capacity. So, in the present work five different feed forward back propagation ANN models by varying number of hidden layer neurons were developed for estimation of Harangi reservoir storage, Karnataka, India. The first 2 years (2010–12) data was used for supervised training and remaining data (2013–14) was used in prediction. The predictive accuracy using the statistical parameters like correlation coefficient (R) and mean absolute percentage error (MAPE) were found within the acceptable limit. Result shows that, ANN model with five hidden neurons (i.e., network architecture of 6-5-1) is performing well compared to all other models for prediction of reservoir storage estimation. © Springer Nature Singapore Pte Ltd. 2019.Item Remote sensing image based nearshore bathymetry extraction of Mangaluru coast for planning coastal reservoir(Elsevier, 2020) Kumari, P.; Ramesh, H.Water is an essential source for numerous day-to-day necessities. The storage of flood water in the nearshore region of sea by constructing a dyke is called coastal reservoir. Bathymetry of nearshore region is necessary, which is extracted through remote sensing technique in Mangaluru coast, India, to plan and identify a suitable site for coastal reservoir in this study. Single linear regression (SLR) and multi linear regression (MLR) algorisms with Landsat 8 OLI/TIRS data were used and calibrated with hydrographic charts. The SLR method produced bathymetry with coefficient of determination of 0.76 and 0.70 for Blue and NIR bands, respectively, and 0.88 for combination of Blue and NIR bands in MLR method, which is considerably high and accurate. The depth obtained was in the range of 0-20m, from the shoreline up to 10km offshore. The study helps in determining area and volume of the coastal reservoir. © 2020 Elsevier Inc.Item Evaluating the reliability of open-source hydrodynamic models in flood inundation mapping: an exhaustive approach over a sensitive coastal catchment(Elsevier, 2024) Thakur, D.A.; Suryawanshi, V.; Ramesh, H.; Prakash Mohanty, M.P.Recently, the frequency and severity of flooding events have escalated, underscoring the urgent requirement for effective flood management strategies. Comprehensive flood inundation mapping and the precise identification of flood-prone areas are indispensable tools in this endeavor. In the current research, the Hydrologic Engineering Center's River Analysis System (HEC-RAS) version 6.3 software was employed to create inundation maps and delineate areas at risk of flooding for the Netravati-Gurupura River basins. Flood flows for various years have been simulated across the river basin, with terrain characteristics derived from the 30-m spatial resolution Shuttle Radar Topography Mission digital elevation model. The simulation of flow within the model was conducted using daily discharge data, with the model being calibrated at an optimal Manning's roughness coefficient value of n = 0.032. The calibration process was carried out by performance metrics, including the coefficient of determination, Nash-Sutcliffe efficiency, and the index of agreement, to ensure precision and reliability in the model's outputs. The outcomes of the model simulation provided depth, velocity, and water surface elevation data, from which potential flood-prone zones were identified. Model performance validation was conducted for the flood events of 2007 and 2014, revealing that the results of the statistical parameters fell within the anticipated range. This study demonstrated that flood events could be effectively simulated using the HEC-RAS two-dimensional model, enabling the identification of flood-prone areas. This research underscores the pivotal role of open-source hydrodynamic modeling in enhancing our predictive capabilities and preparedness for flood events. This approach not only optimizes resource allocation for flood defense infrastructure but also informs the strategic planning of land use, minimizing potential flood damage and bolstering environmental and societal well-being. © 2025 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies.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 Groundwater modeling to simulate groundwater levels due to interlinking of rivers in Varada river basin, India(2011) Ramesh, H.; Mahesha, A.Using a two-dimensional Gelarkin finite element model, the present study characterizes groundwater flow in a Varada basin, a semi humid area of Karnataka, India. The model characterization involved taking field data by conducting pump tests describing an aquifer system. Geological geometry and the number of aquifers have been analyzed based on a large amount of geological, hydrogeological and topographical data. The aquifer properties are then transformed into input variables that the model code uses to solve governing equations of flow. The results of the field experiments showed that Varada basin is predominantly confined aquifer. For calibrating the numerical groundwater model, the groundwater flow was simulated in steady state. Results of study demonstrate a moderately high correlation between the observed and simulated groundwater level. In addition, the groundwater level and trend in the transient state has also been elucidated. The validated numerical groundwater model was used to predict the groundwater levels due to impact of recharge from the interlinking of rivers in the basin. The model result provides an excellent visual representation of groundwater levels, presenting resource managers and decision makers with a clear understanding of the nature of the interaction of groundwater levels with the proposed interlinking project. Results build a base for further analysis under different future scenarios for implementation. © 2011 IEEE.Item A numerical modeling approach for study of mudbank impact on coastline(Institute of Electrical and Electronics Engineers Inc., 2015) Parvathy, K.G.; Ramesh, H.; Noujas, V.; Thomas, K.V.Coastal zone is the triple interface of land, ocean and atmosphere. Any developmental activity along the coastal zone requires a clear understanding of the dynamic processes controlling its very existence. When most of the processes, which are common to all coastlines are quite well known, there are some localized, but important processes requiring further research for developmental planning. Mudbanks are such an inquisitive coastal phenomenon which occurs only at a few locations in the nearshore waters of the world ocean. Mudbanks, its occurrence, nature, properties and characteristics are interesting subjects from engineering point of view. The objective of the study is to provide an insight of mudbank impact on coastal morphology through a numerical modeling approach. For a better understanding of the influence of mudbanks on coastal morphology, Munambam to Chettuwa sector of Thrissur coast which is a part of Southwest coast of India is considered. In the present study the description of coastline evolution due to impact of mudbank is calculated using LITLINE module of LITPACK software package. It is observed that the occurrence, non-occurrence and migration of mudbanks influence the coastal dynamics significantly along mudbank influenced coastal stretch of Kerala. © 2014 IEEE.Item Effectiveness of contrast limited adaptive histogram equalization technique on multispectral satellite imagery(Association for Computing Machinery acmhelp@acm.org, 2017) Ganesh, V.R.; Ramesh, H.Contrast Limited Adaptive Histogram Equalization technique (CLAHE) is a widely used form of contrast enhancement, used predominantly in enhancing medical imagery like X-rays and to enhance features in ordinary photographs. This paper aimed to understand the effectiveness of using this technique in multispectral satellite imagery and to study its effectiveness in different regions of the electromagnetic spectrum. This study also aimed at analyzing variations of spatial and spectral resolutions of a sensor affect the performance of the CLAHE technique by means of comparing quantitative parameters of the enhanced images between the sensors. A general idea of the feature that can be enhanced in each spectral region was also studied. The results showed that a comparative study between the CLAHE technique and the conventional global histogram equalization technique resulted in the former technique emerging superior of the two and thereby reconstructed images of better quality. © 2017 Association for Computing Machinery.Item Modeling of the transport of leachate contaminant in a landfill site: A case study in mangaluru(CRC Press/Balkema, 2018) Divya, A.; Shrihari, S.; Ramesh, H.Ground water flow and the solute transport model MODFLOW and MT3DMS were established to determine the spread of contamination from a landfill maintained by Mangaluru City Corporation at Vamanjoor, located nearly 8.5 km from the center of the city. As Vamanjoor is home for many educational institutes and also a residential area, the spread of the contamination has to be analyzed. For this study, the aquifer considered is a subbasin of the Gurupur basin. This study has focused on handling the data available in the most efficient way to develop a consistent simulation model. The model was calibrated successfully with RMSE value of observed versus simulated head as 0.32 m. The evaluation of model was also done by comparing with the measured water head and chloride level from the field on a seasonal basis. After validating successfully, the model was run to determine the extent of contamination and also to forecast a scenario for maximum rainfall. The results show that the contamination has spread to a distance of 1 km from the landfill and with maximum rainfall the spread will be around 1.8 km from the landfill. © 2018 Taylor & Francis Group, London.Item Modelling of groundwater quality using bicarbonate chemical parameter in Netravathi and Gurpur river confluence, India(American Institute of Physics Inc. subs@aip.org, 2018) Sylus, K.J.; Ramesh, H.In the coastal aquifer, seawater intrusion considered the major problem which contaminates freshwater and reduces its quality for domestic use. In order to find seawater intrusion, the groundwater quality analysis for the different chemical parameter was considered as the basic method to find out contamination. This analysis was carried out as per Bureau of Indian standards (2012) and World Health Organisations (1996). In this study, Bicarbonate parameter was considered for groundwater quality analysis which ranges the permissible limit in between 200-600 mg/l. The groundwater system was modelled using Groundwater modelling software (GMS) in which the FEMWATER package used for flow and transport. The FEMWATER package works in the principle of finite element method. The base input data of model include elevation, Groundwater head, First bottom and second bottom of the study area. The modelling results show 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 519m towards the freshwater zone of the study area. © 2018 Author(s).Item Impact of land use land cover change on run off generation in tungabhadra river basin(Copernicus GmbH info@copernicus.org, 2018) Venkatesh, K.; Ramesh, H.Streamflow can be affected by a number of aspects related to land use and can vary promptly as those factors change. Urbanization, deforestation, mining, agricultural practices and economic growth are some of the factors related to these land use changes which alter the stream flow. In the present study, the impact of land use land cover change (LULC) on stream flow is studied by using SWAT model for Tungabhadra river basin, located in the state of Karnataka, India. Tungabhadra river originates in the Western Ghats of Karnataka and flows towards north-east and joins the river Krishna. The land use maps of 1993, 2003 and 2018 are used for assessing the stream flow changes with respect to LULC. Calibration and validation of the model for streamflow was carried out using the SUFI-2 algorithm in SWAT-CUP for the years 1983-1993 and 1994-2000 respectively. Statistical parameters namely Coefficient of Determination (R2) & Nash-Sutcliffe (N-S) were used to assess the efficiency and performance of the SWAT model. It was found that the observed and simulated streamflow values are closely matching, which in turn projects that the model results are acceptable. The calibrated model was used for simulation of future dynamic land use scenario to assess the impact on streamflow. The results can be used for conservation of water and soil management. © 2018 Authors.