Faculty Publications
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Item WAVE FORECASTING FOR THE WEST COAST OF IHDIA(American Society of Civil Engineers (ASCE), 1970) Dattatri, J.; Renukaradhya, P.S.The applicability of the general Wave Forecasting procedures like the SMB and the PNJ methods, to the Indian coasts is studied. The study consisted in analysing the bynoptic charts to obtain the necessary wind characteristics. The computed wind characteristics were used in the above Forecasting methods to yield significant wave heights These were compared with the wave characteristics as recorded by a sub-surface pressure type recorder after suitable modifications to account for the attenuation of wave pressure with depth. The predicted wave heights compare well with the recorded wave heights and the SMB method predicts wave heights better for the case studied. © 1970 American Society of Civil Engineers.Item FIELD STUDY OP SURATHKAL BEACH(American Society of Civil Engineers (ASCE), 1970) Suryaprakasa Rao, P.; Kassim, P.Beach profile observations and sediment sampling were carried out for six months at frequent intervals to study the seasonal changes of the beach. Iht study is helpful in bringing out the qualitative and quantitative changes of the beach under varying wave and tide conditions. Useful information is obtained and presented regarding i) the maximum rate of erosion ii) the total quantity of material eroded iii) the critical wave steepness values which changed from depositing to eroding nature and iv) the sediment characteristics of the beach. © 1970 American Society of Civil Engineers.Item Effect of pH on the geotechnical properties of laterite(2006) Sunil, B.M.; Nayak, S.; Shrihari, S.Environmental Geotechnology has emerged as an interdisciplinary science, aiming and forecasting, analyzing and solving the geotechnical problems involving the influence of environmental factors. Lateritic soil of west coast region of India was studied to investigate the effect of soaking on the engineering properties and chemical characteristics of soil, soaked in different pH solutions (pH = 5.0, pH = 7.0, pH = 8.0). 12 N hydrochloric acid and 15 M ammonia solution were used to monitor the pH of the solution for about ninety days. Results showed that the pH of the solution has strong influence on the chemical characteristics of lateritic soil. The engineering properties of soil are altered when compared with the initial characteristics of the soil. The reason for this observed behavior of the soil is addressed in this paper. © 2006 Elsevier B.V. All rights reserved.Item Performance evaluation of reference evapotranspiration equations across a range of Indian climates(2006) Nandagiri, L.; Kovoor, G.M.Reference crop evapotranspiration (ET0) is a key variable in procedures established for estimation of evapotranspiration rates of agricultural crops. In recent years, there is growing evidence to show that the more physically based FAO-56 Penman-Monteith (PM) combination method yields consistently more accurate ET0 estimates across a wide range of climates and is being proposed as the sole method for ET0 computations. However, other methods continue to remain popular among Indian practitioners either because of traditional usage or because of their simpler input data requirements. In this study, we evaluated the performances of several ET0 methods in the major climate regimes of India with a view to quantify differences in ET0 estimates as influenced by climatic conditions and also to identify methods that yield results closest to the FAO-56 PM method. Performances of seven ET0 methods, representing temperature-based, radiation-based, pan evaporation-based, and combination-type equations, were compared with the FAO-56 PM method using historical climate data from four stations located one each in arid (Jodhpur), semiarid (Hyderabad), subhumid (Bangalore), and humid (Pattambi) climates of India. For each location, ET0 estimates by all the methods for assumed hypothetical grass reference crop were statistically compared using daily climate records extending over periods of 3-4 years. Comparisons were performed for daily and monthly computational time steps. Overall results while providing information on variations in FAO-56 PM ET0 values across climates also indicated climate-specific differences in ET0 estimates obtained by the various methods. Among the ET0 methods evaluated, the FAO-56 Hargreaves (temperature-based) method yielded ET0 estimates closest to the FAO-56 PM method both for daily and monthly time steps, in all climates except the humid one where the Turc (radiation-based) was best. Considering daily comparisons, the associated minimum standard errors of estimate (SEE) were 1.35, 0.78, 0.67, and 0.31 mm/day, for the arid, semiarid, subhumid, and humid locations, respectively. For monthly comparisons, minimum SEE values were smaller at 0.95, 0.59, 0.38, and 0.20 mm/day for arid, semiarid, subhumid, and humid locations, respectively. These results indicate that the choice of an alternative simpler equation in a particular climate on the basis of SEE is dictated by the time step adopted and also it appears that the simpler equations yield much smaller errors when monthly computations are made. In order to provide simple ET0 estimation tools for practitioners, linear regression equations for preferred FAO-56 PM ET0 estimates in terms of ET0 estimates by the simpler methods were developed and validated for each climate. A novel attempt was made to investigate the reasons for the climate-dependent success of the simpler alternative ET0 equations using multivariate factor analysis techniques. For each climate, datasets comprising FAO-56 PM ET0 estimates and the climatic variables were subject to factor analysis and the resulting rotated factor loadings were used to interpret the relative importance of climatic variables in explaining the observed variabilities in ET0 estimates. Results of factor analysis more or less conformed the results of the statistical comparisons and provided a statistical justification for the ranking of alternative methods based on performance indices. Factor analysis also indicated that windspeed appears to be an important variable in the arid climate, whereas sunshine hours appear to be more dominant in subhumid and humid climates. Temperature related variables appear to be the most crucial inputs required to obtain ET0 estimates comparable to those from the FAO-56 PM method across all the climates considered. © 2006 ASCE.Item Industrial estate planning for Mangalore Taluk in Karnataka, using remote sensing and GIS(2006) Navalgund, L.; Shreedhara, V.; Srinikethan, G.The present work presents a technique to prepare zoning atlas to classify the environment and risks involved in siting an industry. Based on risks involved in a classified zone, the best-suited industries are recommended. Mangalore city has been taken as the study area has for the present work. Sensitivity of study area has been checked in terms of air pollution, surface water pollution and groundwater pollution. The study relies upon the database procured for this purpose from Central Pollution Control Board (CPCB) and Karnataka State Remote Sensing Technology, Bang lore. The database mainly comprises of topographic maps, thematic maps and groundwater information. Buffering and over-laying of the thematic maps have been carried out as per the guidelines of CPCB. © Enviromedia Printed in India. All rights reserved.Item Natural and anthropogenic factors controlling the dissolved organic carbon concentrations and fluxes in a large tropical river, India(2006) Balakrishna, K.; Kumar, I.A.; Srinikethan, G.; Mugeraya, G.Carbon studies in tropical rivers have gained significance since it was realized that a significant chunk of anthropogenic CO2 emitted into the atmosphere returns to the biosphere, that is eventually transported by the river and locked up in coastal sediments for a few thousand years. Carbon studies are also significant because dissolved organic carbon (DOC) is known to complex the toxic trace metals in the river and carry them in the dissolved form. For the first time, this work has made an attempt to study the variations in DOC concentrations in space and time for a period of 19 months, and estimate their fluxes in the largest peninsular Indian river, the Godavari at Rajahmundry. Anthropogenic influence on DOC concentrations possibly from the number of bathing ghats along the banks and domestic sewage discharge into the river are evident during the pre-monsoon of 2004 and 2005. The rise in DOC concentrations at the onset of monsoon could be due to the contributions from flood plains and soils from the river catchment. Spatial variations highlighted that the DOC concentrations in the river are affected more by the anthropogenic discharges in the downstream than in the upstream. The discharge weighted DOC concentrations in the Godavari river is 3-12 times lower than Ganga-Brahmaputra, Indus and major Chinese rivers. The total carbon fluxes from the Godavari into the Bay of Bengal is insignificant (0.5%) compared to the total carbon discharges by major rivers of the world into oceans. © Springer Science+Business Media, Inc. 2006.Item Characterization of the MSW leachate at Mangalore dump yard, India(2006) Ravishankar, R.; Madhuri, B.; Mugeraya, G.In India, solid waste generation is about 1,00,000 MT per day, of which over 90% is land filled. Landfills are nothing but dump yards without top and bottom impermeable layers. All types of wastes viz., Hazardous, Industrial and even biomedical waste are dumped in these yards. Municipal agencies, responsible for handling wastes, are constructing engineered land fills wherever additional land is available as per MSW (Handling & Management) Rules 2000. The rule stipulates the same limits for leachate discharge as that of industrial wastes. But the characteristics of leachate are not available with the authorities to decide on the system of treatment process. As new landfills are being constructed it is very essential to have a data on the MSW leachate characteristics for deciding on the best treatment method. Therefore in this study the characteristics of the leachate generating from Mangalore MSW landfill was studied during July 2004 to November 2004. pH of the leachate is on the basic side with the value around 8.1±0.2. There is no much variation in the temperature as it was 27°C during July'04 and increased only by 2°C to 29.2°C. towards the end of the study period. Total solids initially decreased from 12800 mg/L to 10300 mg/L due to post monsoon season and as the rainwater dilution decreases, the value of solids increased to 14530 ppm. Total dissolved solids gradually increased from 6700ppm to 10,530 ppm, which is very high compared to standards (2100 ppm). BOD and COD values gradually increased from 200 to 1200 ppm and 2000 to 7200 ppm respectively. This gradual increase can be attributed to the decreased amount of infiltration. These values are much higher than the stipulated standards. Copyright © Enviromedia.Item Development of coastal vulnerability index for Mangalore coast, India(2007) Hegde, A.V.; Reju, V.R.The paper presents the coastal vulnerability index (CVI) for the estimation of vulnerability of the coastal region of Mangalore coast, India, from Talapady to Surathkal. The CVI is an indication of the relative vulnerability of the various segments of the Mangalore coast to coastal erosion hazards. The following variables are used in the estimation of CVI, which is used to rank the vulnerability of the coastal regions: geomorphology, regional coastal slope, shoreline change rates, and population. The rankings for each variable were combined and an index value calculated for 1? X 1? grid cells covering the study area.Item Spatial and temporal variations in water quality, major ions and trace metals(2007) Deepa, V.J.; Balakrishna, K.; Mugeraya, G.; Srinkethan, G.; Krishnakumar, P.K.Godavari river at Rajahmundry is monitored for a period of seven months at five stations along its course for the physicochemical parameters, major ions and trace metals. This study is made to obtain a baseline data of the existing pollutants in this 'hotspot', which is set to become the industrial hub of Andhra Pradesh. Results indicate that A P Paper Mills may not be polluting the river at this period, contrary to what was expected. Clear picture will emerge, once the data for the rainy season is available. Local pollution from detergents and soap in the river is seen in the downstream (station VIP) as lot of bathing and washing activity is done on the banks. There is no pollution of Cu, Ni, Pb, As and Co in the Godavari river at Rajahmundry. In general the pollutant levels in all the stations analysed is within the prescribed limits set by BIS and WHO standards. Copyright © Enviromedia.Item Simulation of varada aquifer system for sustainable groundwater development(2008) Ramesh, H.; Mahesha, A.Groundwater flow modeling has been used extensively worldwide with varying degrees of success. The ability to predict the groundwater flow is critical in planning and implementing groundwater development projects under increasing demand for fresh water resources. This paper presents the simulation of the aquifer system for planning the groundwater development of Varada basin, Karnataka, India using the Galerkin finite-element method. The government of Karnataka State, India is implementing the World Bank assisted project, "Jal Nirmal" for a sustainable development of the region, thereby ensuring a safe supply of drinking water to the northern districts of the state. Varada basin is one of the beneficiaries of the project in Haveri district. Field tests carried out in the study area indicate that the region is predominantly a confined aquifer with transmissivity and storage coefficients ranging from 5.787×10-6m2/s (0.500 m2/day) to 4.213×10-3m2/s (3.640×102m2/day) and 0.011-0.001× 10-2, respectively. This study mainly emphasizes the spatial and temporal variability of groundwater potential under different developmental scenarios. The model predictions were reasonably good with correlation coefficients ranging from 0.78 to 0.91 with the root mean square error of about 0.46-0.78 during calibration and validation. The stated accuracies are based on comparisons between measured and calculated heads. The outcome of the study would be a useful input for the conjunctive use of surface water and groundwater planning for the sustainable development of the region. © 2008 ASCE.