Faculty Publications
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Item Coastal vulnerability assessment of the future sea level rise in Udupi coastal zone of Karnataka state, west coast of India(2009) Dwarakish, G.S.; Vinay, S.A.; Natesan, U.; Asano, T.; Kakinuma, T.; Venkataramana, K.; Pai, B.J.; Babita, M.K.Udupi coast in Karnataka state, along the west coast of India, selected as a study area, is well known for sandy beaches, aquaculture ponds, lush greenery, temples and major and minor industries. It lies between 13°00?00?-13°45?00? north latitudes and 74°47?30?-74°30?00? east longitudes, the length of the coastline is 95 km, and is oriented along the NNW-SSE direction. It is vulnerable to accelerated sea level rise (SLR) due to its low topography and its high ecological and touristy value. The present study has been carried out with a view to calculate the coastal vulnerability index (CVI) to know the high and low vulnerable areas and area of inundation due to future SLR, and land loss due to coastal erosion. Both conventional and remotely sensed data were used and analysed through the modelling technique and by using ERDAS Imagine and geographical information system software. The rate of erosion was 0.6018 km2/yr during 2000-2006 and around 46 km of the total 95 km stretch is under critical erosion. Out of the 95 km stretch coastline, 59% is at very high risk, 7% high, 4% moderate and 30% in the low vulnerable category, due to SLR. Results of the inundation analysis indicate that 42.19 km2 and 372.08 km2 of the land area will be submerged by flooding at 1 m and 10 m inundation levels. The most severely affected sectors are expected to be the residential and recreational areas, agricultural land, and the natural ecosystem. As this coast is planned for future coastal developmental activities, measures such as building regulation, urban growth planning, development of an integrated coastal zone management, strict enforcement of the Coastal Regulation Zone (CRZ) Act 1991, monitoring of impacts and further research in this regard are recommended for the study area. © 2009 Elsevier Ltd. All rights reserved.Item Importance of geology and soil survey for mobile communication site planning using RS/GIS technology(2010) Naveenchandra, B.; Lokesh, K.N.; Usha; Gangadhara Bhat, H.G.Geology and Soil survey constitutes a valuable resource inventory linked with the survival of life on the earth. The technological advancements in the field of remote sensing and Geographical Information System have been a boon for such surveys. The present paper describes the role of Remote sensing and Geographical Information System (GIS) technologies for geological mapping and characterizing the importance of soils at various scales for identification of suitable sites for mobile communication network. Cellular network design is becoming more and more important since the network quality is highly dependent on the distribution of base stations. To design a cellular network for a particular region efficiently and accurately, the site suitability is an important determination. The country's mobile services market is forecast to grow by a compound annual rate of 28.3% in next five years. India is a vibrant market from communications point of view. The subscriber base in the wireless market in India, the world's fastest growing telecom market reached another milestone when it surpassed 200 million subscribers in Aug 2008. At present there are around 54000 cell sites operated by different GSM/CDMA operators. This number would further go up to 80,000 in next couple of years. To serve an increasing number of users requires an increasing number of base stations. Thus, operators must carefully plan the deployment and configurations of radio base stations to support voice and data traffic at a level of quality expected by customers. The present study carried out in the Udupi district of Karnataka State based on IRS 1C/1D LISS-III and CARTOSAT-1 satellite data. Various thematic maps like geology, soil, geomorphology, slope and land use/land cover with DEM has helped in understanding the terrain in a better way. The multi spectral satellite data in conjunction with SuperGIS, SuperPad and Getac GPS hardware have helped to formulate suitable plans and strategies for an effective Telecom planning and development in Udupi district. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item A note on the occurrence of landslides in Araku valley and its environs, Visakhapatnam district, Andhra Pradesh, India(2010) Balaji, P.; Pavanaguru, R.; Venkat Reddy, D.The occurrence of landslides in Araku valley and its environs of Visakhapatnam district of Andhra Pradesh have been studied. The slides occurred in a rugged hilly terrain which is a part of Eastern Ghats Mobile Belt. The slides are predominantly debris slides of varying dimensions and occurred in khondalitic country having slopes of the order of 30°. The debris are composed mostly of scree, soil, boulders and weathered rock. The significant causative factor of triggering slides was manifested through heavy rainfall associated with cyclonic storm. The causes of the slope failure include toe erosion, debris accumulation that resulted in blockade, overtopping and changes in the stream courses. The present paper is aimed to identify damage assessment, magnitude of slides and causes of slides with an attempt to suggest some long term corrective and control measures in the area. © 2010 Cafet-Innova Technical Society.Item Impact assessment of watershed development programme - A case study of Itagi watershed(2010) Palakshappa, K.; Nagaraj, M.K.; Shivapur, A.V.Soil, water and vegetation are the important gifts of nature to mankind. Welfare and development of mankind and its civilization revolves around conservation and development of these vital natural resources, which are so interdependent that one can not be managed efficiently without the other two. Watershed Development Programs (WDP) going on in India basically as soil and water conservative programs (as a policy response to the increasing environmental crisis and non-sustainability of agriculture especially in the dry land/semi-arid regions) has modified substantially with the introduction of watershed guidelines in 1994 by the Government of India. In the present study the area considered for assessment is Itagi sub watershed in Ranebennur taluk, Haveri district, Karnataka. During the watershed development programme soil and water conservation structures were constructed in the study area in the year 2004. The analysis of data reveals that there is an improvement in the groundwater recharge, increase in yield of the wells, increase in agricultural production, reduction in soil erosion and many other tangible and intangible benefits as a result of this watershed development programme. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Identification of Artificial recharge sites in hard rock terrain using RS and GIS in Chintapally Mandal, Nalgonda District, Andhra Pradesh, India(2010) Raju, A.; Reddy, A.G.S.; Venkat Reddy, D.A study has been undertaken to identify the favorable areas for artificial recharge in Chintapally mandal in Nalgonda district, Andhra Pradesh. Geographical Information System (GIS) and Remote Sensing technology contributes an efficient and effective result oriented methods for studying the occurrence and movement of groundwater resources. Integration of various thematic layers such as geomorphology, slope, soil types, lineament density, and drainage density have been used to identify the suitable zones for the artificial recharge in the study area. For identifying the suitable zones, weightage and ranking scores were assigned to each thematic layer then using ARC/INFO GIS software, the above themes have been integrated and the areas suitable for artificial recharge have been identified using spatial analysis tools from GIS environment. The favorable areas for artificial recharge have been categorized into Very Good, Good, Moderate to Good, Moderate, Poor to Moderate and poor for recharge in the study area. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Analysis of observed soil moisture patterns under different land covers in Western Ghats, India(2011) Venkatesh, B.; Lakshman, N.; Purandara, B.K.; Reddy, V.B.An understanding of the soil moisture variability is necessary to characterize the linkages between a region's hydrology, ecology and physiography. In the changing land use scenario of Western Ghats, India, where deforestation along with extensive afforestation with exotic species is being undertaken, there is an urgent need to evaluate the impacts of these changes on regional hydrology. The objectives of the present study were: (a) to understand spatio-temporal variability of soil water potential and soil moisture content under different land covers in the humid tropical Western Ghats region and (b) to evaluate differences if any in spatial and temporal patterns of soil moisture content as influenced by nature of land cover. To this end, experimental watersheds located in the Western Ghats of Uttara Kannada District, Karnataka State, India, were established for monitoring of soil moisture. These watersheds possessed homogenous land covers of acacia plantation, natural forest and degraded forest. In addition to the measurements of hydro-meteorological parameters, soil matric potential measurements were made at four locations in each watershed at 50 cm, 100 cm and 150 cm depths at weekly time intervals during the period October 2004-December 2008.Soil moisture contents derived from potential measurements collected were analyzed to characterize the spatial and temporal variations across the three land covers. The results of ANOVA (p<0.01, LSD) test indicated that there was no significant change in the mean soil moisture across land covers. However, significant differences in soil moisture with depth were observed under forested watershed, whereas no such changes with depth were noticed under acacia and degraded land covers. Also, relationships between soil moisture at different depths were evaluated using correlation analysis and multiple linear regression models for prediction of soil moisture from climatic variables and antecedent moisture condition were developed and tested. A regression model relating near-surface soil moisture (50 cm) with profile soil moisture content was developed which may prove useful when surface soil moisture contents derived from satellite remote sensing are available. Overall results of this study indicate that while the nature of land cover has an influence on the spatio-temporal variability of soil moisture, other variables related to topography may have a more dominant effect. © 2010 Elsevier B.V.Item Soil water fluxes under different land covers - A case study from Western Ghats, India(2011) Venkatesh, B.; Nandagiri, L.; Purandara, B.K.Knowledge of soil water fluxes is essential in hydrologic studies related to infiltration, runoff, ground water recharge and water uptake by vegetation. Previous studies have investigated the role played by soil and atmospheric factors on soil water fluxes in the unsaturated zone, but few studies have investigated the role played by vegetation or land cover. The present study was taken up understand the effect of land cover on soil water fluxes through long-term field measurements made in three experimental watersheds located in Western Ghats mountain ranges covering a portion of Uttara Kannada District, Karnataka State, India. Soil and climatic conditions were the same for the selected watersheds but they possessed different land covers - natural forest, degraded forest and acacia plantation. In addition to measurements of hydro-meteorological parameters, soil matric potential measurements were made at 4 locations in each of the watersheds up to a depth of 150 cm at an interval of 50 cm. Measurements were made for a period of 2 years (2007-2008) at weekly time intervals Depth-wise soil matric potential measurements were used to estimate soil water fluxes using Darcy's equation for unsaturated porous media. The estimated values of soil water fluxes were analyzed for their temporal distribution and stability. Results indicated that there is an improvement in soil moisture holding under the acacia plantation in comparison to degraded watershed. The estimated deviation of the soil water flux from the field average values indicate that the points located on milder slopes are representative of watershed mean soil water flux. Results also indicated the temporal persistence of soil water fluxes. © 2011 CAFET-INNOVA technical society. All right reserved.Item Neotectonic evolution of Coastal Rivers of Mangalore, Karavali Karnataka, India(2011) Ravindra, B.M.; Venkat Reddy, D.The geomorphic evolution of Mangalore is intimately influenced by Neo-tectonic activities that affected the West Coast and peninsular India that led to the upliftment of Sahyadri Range. Mangalore pediplain has preserved signatures of (1) An older cycle of River system that existed prior to the rise of Sahyadri and (2) Several phases of migration paths of the West flowing Sahyadri Rivers, reflecting geomorphic changes in the pediplain in response to the tectonic strains generated during the rise of the Sahyadri range and northward drift of the Indian subcontinent. The compressional stress derived from the phenomenon of Sea floor spreading is manifested in the Karavali pediplain, in the form of EW and NNW intersecting transform faults that activate periodically and trigger microseismic disturbances severe sea erosions or landslides under adverse hydrological conditions. Similarly under the regime of compressional stress, the Mangalore pediplain evinces evidences of sequential development of anticlinal upwarps that broke into horsts and grabens separated by escarpments. The Holocene fluvial evolution of Mangalore consisted of migration of the two Rivers in opposite directions with progressive passage of time in the Holocene. Fluvial geomorphology of Mangalore has also preserved evidences that substantiate shifting of trans-peninsular Mulki - Pulicat Ridge Axis from its original position northwards. The ongoing structural disturbances and micro-seismic and allied recent neo-tectonic activities imply that the processes responsible for the creation of the Sahyadri range have not died down yet and are very much in attendance even today. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.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 Valley-Coherent Hot Carriers and Thermal Relaxation in Monolayer Transition Metal Dichalcogenides(American Chemical Society service@acs.org, 2016) Kallatt, S.; Umesh, G.; Majumdar, K.We show room-temperature valley coherence in MoS2, MoSe2, WS2, and WSe2 monolayers using linear polarization-resolved hot photoluminescence (PL) at energies close to the excitation, demonstrating preservation of valley coherence before sufficient scattering events. The features of the copolarized hot luminescence allow us to extract the lower bound of the binding energy of the A exciton in monolayer MoS2 as 0.42 (±0.02) eV. The broadening of the PL peak is found to be dominated by a Boltzmann-type hot luminescence tail, and using the slope of the exponential decay, the carrier temperature is extracted in situ at different stages of energy relaxation. The temperature of the emitted optical phonons during the relaxation process is probed by exploiting the corresponding broadening of the Raman peaks due to temperature-induced anharmonic effects. The findings provide a physical picture of photogeneration of valley-coherent hot carriers and their subsequent energy relaxation pathways. © 2016 American Chemical Society.