Volume - 2 | Issue - 4 by NAMITHA M R
A study on the aquifer characteristics of Tavanur Grama Panchayat, Malappuram, Kerala was conduct... more A study on the aquifer characteristics of Tavanur Grama Panchayat, Malappuram, Kerala was conducted across 23 VES locations by vertical electrical sounding technique. The study aimed to analyse the hydro-geological characteristics of the geological formations of Tavanur Panchayat using an electrical resistivity meter. The data obtained from the vertical electrical sounding was interpreted using IPI2WIN software and sounding curves were generated which depict the changes in apparent resistivity with the distance between electrodes or with depth. From the sounding curves obtained from IPI2WIN software, it was found that among 23 locations, seventeen locations showed three layered substrata and four locations showed four layered substrata. A total of 7 types of sounding curves were obtained viz., H, K, A, Q, HA, HK and QH. Out of the 23 locations, 8 locations showed the H type and 3 locations showed A type sounding curves. The resistivity and pseudo cross sections of 6 sections including 3 to 7 VES locations were also prepared and analysed. From this study, it could be concluded that the majority of the study area has lateritic soil to hard laterite with medium to high groundwater potential and the areas were found suitable for the construction of open wells.
A 34-year rainfall data from 1976 to 2009 of ten sub-basins of the Vaigai River in Tamil Nadu wer... more A 34-year rainfall data from 1976 to 2009 of ten sub-basins of the Vaigai River in Tamil Nadu were collected and analysed statistically using various probability distribution functions. The best-fit probability distributions for the annual, monthly and seasonal rainfall for the study area were found using two goodness-of-fit tests. The Box-Jenkins Autoregressive Integrated Moving Average (ARIMA) methodology has been adopted for model identification, diagnostic checking and forecasting the study area's annual rainfall. The best ARIMA models were selected for each subbasin and the average annual precipitation for 2010, 2015, 2020 and 2025 has been forecasted. The forecasted result compared well with observed dataup to 2020, which indicates the appropriateness of the model.
Legal restrictions are imposed on the public sharing of raw data. However, authors have full righ... more Legal restrictions are imposed on the public sharing of raw data. However, authors have full right to transfer or share the data in raw form upon request subject to either meeting the conditions of the original consents and the original research study. Further, access of data needs to meet whether the user complies with the ethical and legal obligations as data controllers to allow for secondary use of the data outside of the original study.
The analysis of 27 years rainfall data of Kumulur region was conducted using two types of probabi... more The analysis of 27 years rainfall data of Kumulur region was conducted using two types of probability distributions, viz Gumbel distribution and generalised extreme value distribution. The method of L-moments was used for the analysis. Annual one day maximum and 2, 3,4, 5 and 7 consecutive days maximum rainfall data for 27 years was analysed and the return levels for 2, 5, 10 and 25-years were calculated using the proposed probability distribution functions. Chisquare test was conducted for comparison of the observed and expected return levels obtained using both the distributions. The statistical analysis revealed that, the annual maxima rainfall data for one day maxima and consecutive days maxima of Kumulur region fits best with the generalised extreme value distribution.
In this study, the unsaturated hydraulic conductivity (K) of sandy loam soil was determined throu... more In this study, the unsaturated hydraulic conductivity (K) of sandy loam soil was determined through inverse modelling. The transient unsaturated water flow was simulated by numerically solving the Richards equation with the finite element code of Hydrus-1D. The cumulative infiltration flux across a boundary at different time was used as the input variable to optimise the soil hydraulic parameters. The inverse method generally uses a weighted least-squares approach in which numerically simulated data are fitted to the measured data. van Genuchten hydraulic model was chosen for the determination of unsaturated hydraulic conductivity. The soil hydraulic parameters viz. residual water content (θr), saturated water content (θs), inverse of air entry value (α), water retention parameter (n), and saturated hydraulic conductivity (Ks) were optimised in successive iterations. The optimised parameter values were fitted in the van Genuchten model for obtaining the unsaturated hydraulic conductivity of the proposed soil.
In this study, a laboratory soil column experiment was carried out for estimating the dispersivit... more In this study, a laboratory soil column experiment was carried out for estimating the dispersivity (?) in sandy loam soil by the inversion of the Advection-Dispersion Equation. An 89 cm deep and 15 cm diameter cylindrical column was filled with sandy loam soil in such a way that the bulk density of the soil in field condition was strictly satisfied in the column. Potassium bromide was used as the conservative tracer in the study. The tracer concentration was allowed to pass through the column at a constant rate and the leachate collected at different time periods were tested for the concentration of bromide. The experiment was carried out until the relative concentration (c/c0) has reached 1. The calculated relative concentration was plotted against time for obtaining the observed breakthrough curve (BTC). Another BTC was plotted using the analytical solution of Advection Dispersion Equation. The effective dispersion coefficient (De)value which gave the best fit between these two curves was chosen by trial and error method and the dispersivity of the soil was calculated (De = ?v)for a constant pore water velocity (v). The dispersivity of the sandy loam soil under study was found to be 1.7 cm which matches well with the previous researches. M. R. Namitha | V. Ravikumar"Determination of Dispersivity in A Laboratory Soil Column" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: http://www.ijtsrd.com/papers/ijtsrd14580.pdf
Papers by NAMITHA M R
Journal of Pharmacognosy and Phytochemistry, 2019
A statistical analysis of 27 years rainfall data of Kumulur region in Trichy district of Tamil Na... more A statistical analysis of 27 years rainfall data of Kumulur region in Trichy district of Tamil Nadu was conducted using Gumbel distribution and Generalised Extreme Value (GEV) distribution. The method of L-moments was used for determining the parameters for both distributions. Annual maximum rainfall for 2, 3,4, 5 and 7 consecutive days for the available 27 years were analysed and the return levels for four assumed return periods viz. 2, 5, 10 and 25-years were calculated using both the probability distribution functions. The goodness-of-fit of the distributions were analysed by conducting a chi-square test for the observed and expected return levels. The consecutive days maximum rainfall data found to fit best with generalised extreme value distribution. The Empirical Reduction Formula proposed by the Indian Meteorological Department was used for the calculation of short duration for 1-hr, 2-hr, 3-hr, 5-hr, and 8-hr. From the derived short duration rainfall depths, the intensity of the rainfall was calculated. The rainfall Intensity-Duration-Frequency (R-IDF) curves were plotted for the region and the corresponding empirical models were derived.
Journal of Pharmacognosy and Phytochemistry , 2019
Groundwater model has become an essential tool for hydro geologists to perform various tasks incl... more Groundwater model has become an essential tool for hydro geologists to perform various tasks including the assessment and prediction of groundwater, the detection of groundwater pollution etc. The large-scale regional groundwater systems are simulated using various user-friendly modelling tools working on the recent powerful computers. The main components of modelling include the conceptual model, the mathematical model and the graphical representation of hydrogeological system. In this study, a three-dimensional finite difference modelling program namely Visual MODFLOW was used for the study and prediction of aquifer system in a drought prone study area. The base map of the study area, various layers of the geological strata and their geological properties, boundary conditions, well data and recharge conditions were fed in to the model as inputs. The model was then calibrated and validated, after which future groundwater conditions were predicted. Introduction Groundwater is the most treasured and widely distributed natural water resource, which constitutes the largest available source of water for water supply and irrigation in semi-arid regions. The total water resource available in the world is estimated as 1.37x10 8 million ham. Only 2.8% of this water is available as fresh water at any time on the earth. This 2.8 % includes 2.2% of surface water and 0.6% of ground water, which is available beneath the earth's surface. Out of the 0.6 %, only the water available within 800 m depth be economically extracted using the present drilling technology. This accounts to 0.3% (41.1x10 4 million ham) of the total ground water. So, groundwater can be referred as the largest fresh water source on earth other than the polar ice caps and glaciers. It was accounted that amount of ground water within 800 m from the ground surface is over 30 times the amount in all fresh water lakes and reservoirs, and about 3000 times the amount in the stream channels. More than 90% of our rural population is primarily dependent on groundwater (Chandrasekhar et al., 1999) [2]. Nowadays, the depletion of groundwater is undergoing a rapid increment for meeting the water needs of increasing population. So, it is important to analyze and predict the future trends in groundwater flow. Moreover, the contaminations in groundwater should also be assessed for the groundwater flow models are used to calculate the rate and direction of movement of groundwater through aquifers (Khadri and Chaitanya, 2016) [3]. In present study, Visual MODFLOW 2.8.1. Package is used for the assessment and prediction of groundwater in the study area.
International Journal of Current Microbiology and Applied Sciences , 2019
The analysis of one-day maximum rainfall for 27-years rainfall data in Kumulur region was conduct... more The analysis of one-day maximum rainfall for 27-years rainfall data in Kumulur region was conducted using Gumbel distribution and Generalized Extreme Value distributions. The parameters of the distributions were estimated using the method of L- moments. Annual one-day maximum rainfall data for 27-years was analyzed and the return levels for 2, 5, 10 and 25-years were calculated using the proposed probability distribution functions. The goodness of fit of the probability distribution was analysed by conducting Chi-square test. It was found that, the annual maxima rainfall data for one day maximum rainfall of Kumulur region fits best with the Generalized Extreme Value distribution. The short duration rainfall depths for 1-hr, 2-hr, 3-hr, 5-hr, and 8-hr were calculated using the Empirical Reduction Formula proposed by the Indian Meteorological Department. The intensity of the obtained rainfall depths was also calculated. The rainfall Intensity-Duration-Frequency (R-IDF) curves were plotted for the region and the corresponding empirical equations were derived.
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Volume - 2 | Issue - 4 by NAMITHA M R
Papers by NAMITHA M R