Faculty Publications
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Item Association of chlorophyll in a multi-parametric shallow marine environment off the Karnataka-Kerala coast(2011) Raghavan, B.R.; Shylini, S.K.; Deepthi, T.; Kumaraswami, M.; Ashwini, S.; Chauhan, P.; Raman, M.; Venkat Reddy, D.Cluster analysis is a useful data analyzing method to obtain detailed information on the state of the shallow marine environment. The objective of this analysis is to appreciate the clustering patterns of the data of case II shallow marine environment of the eastern Arabian Sea. R-mode cluster analysis was resorted to appreciate the relation of the physical, chemical and biological oceanographic parameters represented as dendograms. A set of 14 parameters were retrieved from seven seasons of the coastal waters from Bekal (North Kerala) to Karwar (North Karnataka). This study exhibits diverse clustering patterns reflecting the heterogeneous behavior of the surface waters of the shallow Arabian Sea enforced by the physical, chemical and biological oceanography of the shallow marine environment. © 2011 CAFET-INNOVA technical society. All right reserved.Item Sedimentary environs of the intertidal areas of Massawa coast: Distribution patterns of ornamental Molluscs (Gastropods) Red Sea, Eritrea(2012) Prabhu, H.V.; Raghavan, B.R.; Deepthi, T.; Asmelash, M.; Fsehatsion, M.; Selemun, M.; Venkat Reddy, D.The distribution patterns of the four orders of Gastropods with respect of the three sites i.e Tiwalet area, Gurgussum I and Gurgussum II of the intertidal areas of Massawa coast, Red Sea have been investigated to appreciate the heterogeneity in the distribution patterns. This is determined by the sediment texture. The habitat of the Molluscs in relation to the substratum in the three sites off Massawa Coast show the nature of the substrate was hard as a result of deposition of the sediments in a shallow and rapidly drying environment. In this study, 30 different species of Gastropoda were identified. All of them are members of the sub class Prosobranchia, and distributed among four orders Neogastropoda, Mesogastropoda, Archaeogastropoda, and Pyramidellomorpha. Based on the statistical Analysis of Variance (ANOVA) carried at 5% level of significance, there was a considerable variation among the three sites in the distribution patterns of the four orders of gastropods. This difference is largely due to the differences in the shell shape and structure, and the sediment textural differences in the three sites. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Terrain analysis and hydrogeochemical environment of aquifers of the southern west coast of Karnataka, India(2012) Honnanagoudar, S.S.; Venkat Reddy, D.; Mahesha, A.Dakshina kannada district is situated in peninsular region. The peninsula is composed of geologically ancient rocks of diverse original and most of them have undergone metamorphism. The early Precambrian tonalitic gneisses invaded by granites, granulites and dolerite dykes. Granulites are mostly restricted to areas south of Mangalore. High grade alumina rich (corundum bearing) metamorphic schists have been encountered and younger alkaline intrusive rocks like Aegerine syenites have been reported. There are five rivers and estuaries. Number of lineaments cut across each other and some lineaments are parallel to each other. The Arabian sea class is the largest among other land cover features in the study area. The river/tidal creek land cover appear as long irregular and sinous in outline. Mulki river, Netravati river, Gurupur river at southern terrain. The qualities of groundwater at sandy aquifer are good, lateritic/weathered gneissic rocks it is sweet. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Comparison of Oceansat-2 scatterometer- to buoy-recorded winds and spatial distribution over the Arabian Sea during the monsoon period(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2015) Gadad, S.; Deka, P.C.For this wind resource assessment (WRA) study, wind speed and direction are the fundamental inputs. Also, these studies are data driven and require large historical wind speed data sets available on the site. This work explores the application of space-based scatterometer winds for assimilation into WRA studies towards the development of offshore wind energy. This article focuses on estimating the performance of Oceansat-2 scatterometer (OSCAT)-derived wind vector using in situ data from buoys at different locations in the Arabian Sea. A comparative study between three methods for estimating the equivalent neutral winds (ENW) for buoys is carried out. OSCAT winds were closest to ENW estimated by the Liu–Katsaros–Businger (LKB) method. The spatial and temporal windows for comparison were 0.5° and ±60 minutes, respectively. The monsoon months (June–September) of 2011 were selected for study. The root mean square deviation for wind speed is less than 2.5 m s?1 and wind direction is less than 20°, and a small positive bias is observed in the OSCAT wind values. From the analysis, the OSCAT wind values are consistent with in situ-observed values. Furthermore, wind atlas maps were developed with OSCAT winds, representing the spatial distribution of winds at a height of 10 m over the Arabian Sea. © 2015 Taylor & Francis.Item Prediction model for peninsular Indian summer monsoon rainfall using data mining and statistical approaches(Elsevier Ltd, 2017) Vathsala, H.; Koolagudi, S.G.In this paper we discuss a data mining application for predicting peninsular Indian summer monsoon rainfall, and propose an algorithm that combine data mining and statistical techniques. We select likely predictors based on association rules that have the highest confidence levels. We then cluster the selected predictors to reduce their dimensions and use cluster membership values for classification. We derive the predictors from local conditions in southern India, including mean sea level pressure, wind speed, and maximum and minimum temperatures. The global condition variables include southern oscillation and Indian Ocean dipole conditions. The algorithm predicts rainfall in five categories: Flood, Excess, Normal, Deficit and Drought. We use closed itemset mining, cluster membership calculations and a multilayer perceptron function in the algorithm to predict monsoon rainfall in peninsular India. Using Indian Institute of Tropical Meteorology data, we found the prediction accuracy of our proposed approach to be exceptionally good. © 2016 Elsevier LtdItem Regional Trends and Spatiotemporal Analysis of Rainfall and Groundwater in the West Coast Basins of India(American Society of Civil Engineers (ASCE), 2022) Krishnan, C.; Mahesha, M.The present study investigates the spatiotemporal variabilities of long-term (1950-2016) rainfall and regional groundwater levels for annual and seasonal periods over the west coast of India. The study area is a narrow strip of land between Western Ghats (mountainous terrain) and the Arabian Sea, extending over 1,500 km from south to north. The Mann Kendall (MK) and Sen's slope estimator established the long-term trend and magnitude of rainfall and groundwater. The nature of trends in the time series of hydroclimatic variables was identified through singular spectrum analysis (SSA). The SSA extracted nonlinear trends along with the shape for both increasing and decreasing trends. Annual and southwest monsoon rainfall exhibited prominent decreasing trends. The percentage departure analysis of rainfall revealed that earlier decades (1950-1980) were the wettest, followed by the drier decades (1980-2016) for Periyar, Varrar, and Netravati and vice versa for Vasishti and Bhatsol. The wavelet spectra for rainfall indicated short- and long-term modulations. The long-term groundwater level trends of 725 wells on the entire west coast showed a significant decline in 13% of wells, and 6% of wells indicated increasing trends. The Monte Carlo-based numerical investigations on the modified MK (mMK) test power indicated the influence of parent distributions on trend detection. The field significance of trends at a 5% significance level was examined using the bootstrap test. The precipitation data were then compared with groundwater level variation at each site, and correlations were established. The declining southwest monsoon rains and their uneven spatial distribution could be attributed to a subsequent decline in the region's postmonsoon groundwater levels. © 2022 American Society of Civil Engineers.