May, 2018 || Volume 22 No.3
1
Efficacy of Integrated Geophysical Techniques in Delineating Groundwater Potential Zones in the Deccan Basalt Region of MaharashtraRam Raj Mathur*1 and Kadari Srinivas Rao2
1Centre of Exploration Geophysics, Osmania University, Hyderabad, India
2Groundwater Surveys and Development Agency, Maharashtra, India
*Corresponding Author: ramrajmathur@gmail.comABSTRACT
We developed a methodology to study the depth and aerial extent of aquifers in the Dhotra-Jahangir area of Washim District, Maharashtra to yield better results with more reliability. The area was selected as a model to solve existing groundwater problems due to the droughts of 2013 and 2016 in Maharashtra.
The 2-D interpretation of the data helped to delineate the groundwater horizons, their thickness and orientation for identifying dug-cum-borehole sites. The higher values of real and imaginary component in the VLF-EM profile indicate a low resistive zone which can be attributed to weathered or fractured basalt. The Dug well at the suggested site revealed the static water level at 3.8 m during April 2013. Thus, the integration of resistivity and VLF-EM methods proved to be effective in locating the sources of groundwater with a yield of about 9500 lph which successfully addressed the problem for drinking and cultivation purposes during the entire year.
Key words: Deccan Basalts, Dhotra Maharashtra, Gradient Resistivity Profiling, VLF?EM method, Vertical Electrical Sounding..
2
Site characterisation using Multi-channel Analysis of Surface Waves at various locations in Kumaon Himalayas, IndiaAnand Joshi*1 and Parul Bhardwaj2
1Department of Earth Science, Indian Institute of Technology Roorkee, Roorkee, India 247667
2KDMIPE, Oil & Natural Gas Corporation Ltd., Dehradun, India 248195
*Corresponding Author: parul1611pandit@gmail.comABSTRACT
Local site amplification is greatly influenced by the top 30 m soil column. Rayleigh waves in top soil, acquired by Multi-channel Analysis of Surface Wave (MASW) technique, are helpful in local site amplification studies. In this paper, the acquired data in Kumaon Himalayas are processed for noise elimination and signal enhancement and also for the estimation of shear wave velocity by using “Seisimager” software. We estimated 2D shear wave velocity (Vs30) down to 30 m depth in Kumaon region. Average Vs30 is found to be in the range of 120 - 712 ms-1 and average predominant frequency in the range of 1.01 - 5.94 Hz. Estimated average shear wave velocity is used for site classification, which can be used for geotechnical characterization of shallow subsurface formations.
Key words: Shear wave velocity, Predominant frequency, MASW, Kumaon Himalayas
3
Application of Crosshole Seismic technique and MASW at Heavy Engineering Site, near Mahabalipuram, Tamilnadu
K. Satish Kumar*, P. Pavan Kishore, G.S. Srinivas, P. Prabhakara Prasad and T. Seshunarayana
CSIR-NGRI, Uppal Road, Hyderabad 500007
*Corresponding Author: satish_marine777@yahoo.co.in
ABSTRACT
Seismic velocities (Vp and Vs) of the subsurface play a vital role in designing the engineering parameters for major civil engineering structures. A case history is presented from the charnockite province in east coast of India near Mahabalipuram, Tamilnadu. As a part of the feasibility study Crosshole seismic and Multi Channel Analysis of Surface waves (MASW) surveys were conducted near a heavy engineering construction site. Vp and Vs are determined up to 55 m depth with an interval of 1.5 m. Dynamic elastic constants, average shear wave velocity, predominant frequency and amplification of the area were calculated. Velocity data reveals that soil cover composition varies with depth, namely, highly weathered, moderately weathered and fresh Charnockite occur successively from top to bottom in the subsurface. Dynamic elastic constants, average shear wave velocity, predominant frequency, and amplification are estimated.
Key words: Vp and Vs, crosshole seismics, MASW and Charnockites
4
Application of Shallow Seismic Studies for Civil Engineering Applications: A case study from Chennai city, TamilnaduG.S. Srinivas, P.Shiva Shankar, K. Satish Kumar*, S.Trupti, P.Pavan Kishore,
K.N.S.S.S.Srinivas and T. Seshunarayana
CSIR-NGRI, Uppal Road, Hyderabad-500007, India.
*Corresponding Author: satish_marine777@yahoo.co.in
ABSTRACT
Shear wave (VS) and P-wave (VP) velocities were estimated for the evaluation of the sub-surface structure along four profiles at CSIR-SERC Campus in Chennai city to aid in the structural design for a proposed high rise building. These velocities are essential parameters for determining the dynamic properties of soil in the shallow subsurface. Dynamic properties, thickness of soil, depth to basement and the associated in-homogeneities such as fractures, joints, voids and shear zones, play a very important role in design and construction of civil structures. Multichannel analysis of surface waves (MASW) and refraction methods were used for the estimation of VS and VP respectively to decipher the subsurface structure in detail. From the Seismic velocity-depth sections, the near surface distribution of rocks, soils and their physical properties were determined to characterize the site conditions. The results indicate a three layered structure with P-wave velocities of 400-500 m/s, 2700-3100 m/s and 5300-5500 m/s and S-wave velocities of >200 m/s, 200 to 300 m/s and >400 m/s up to a depth of 30 m. The obtained results are well correlating with the available borehole lithological data. These results are helpful in civil engineering applications in estimation of elastic properties, depth to bedrock and useful in planning of high rise structures.
Key words: Shear wave velocity, P wave velocity, bedrock, MASW and Structures.
5
Evaluation of Percolation Tank Efficiency on Groundwater Recharge: A Case Study for Karnampettai Percolation Pond, IndiaL.Surinaidu1, A. Raviraj2 and R. Rangarajan1*
1CSIR-National Geophysical Research Institute (NGRI), Hyderabad- 500 007
2Water Technology Center, Tamil Nadu Agriculture University, Coimbatore - 641003
*Corresponding Author: rangarajanngri@gmail.comABSTRACT
AOver abstraction of groundwater when compared to less amount of rainfall recharge throughout India is mainly due to increasing demands for irrigated agriculture causing severe groundwater depletion. Such an alarming situation is increasing unabated in spite of massive water harvesting measures that are implemented through watershed development programs (WDP). In order to improve the artificial percolation efficiency some new developmental programs are being implemented through managed aquifer recharge (MAR) (mainly percolation tanks and check dams). Keeping in view the well known Water Development Programs limitations due to the increasing number of recharging structures and huge cost involved in their construction, it has become necessary and important to evaluate and understand the MAR performance for sustainable management of groundwater resources. The present study examines the percolation efficiency of typical Karnampettai percolation tank located in Tamilnadu, South India using an integrated approach combining geophysical, hydrogeological and geotracer (radiotracer: tritium and chemical tracers: rhodamine B, bromide) investigations. The results indicated that percolation from the tank is 28 to 35 mm/day with an average percolation rate of 32 mm/day. The percolation rate is reduced progressively with a gradual decline of water level in the percolation tank. The average natural recharge (rainfed and irrigation fields) in the study area is 30 mm (8% of the rainfall). The study indicated that 65% of the total rainfall is lost due to soil moisture deficiency caused by evaporation and evapotranspiration. The study also reveals that the groundwater flow velocity near to the percolation pond is 2 m/day with effective groundwater recharge zone of 275 m.
Key words: Percolation tank, tracers, MAR, WDP, Karnampettai..
6
Hydrochemical Signatures for Identification of Fresh and Saline Water Resources, along Visakhapatnam-Bhimunipatnam CorridorP. Padmavathi Devi
DST Woman Scientist, Dept. of Geophysics, Andhra University, Visakhapatnam
E-mail:padmavathidv399@gmail.comABSTRACT
Phenomenal increase in the demand for potable water to meet the basic needs of the ever increasing population has led to significant increase in the exploitation of groundwater, especially in many segments of our country where surface water availability is meager. One such segment includes the urban conglomeration in and around Visakhapatnam. To ensure that many localities along and across Visakhapatnam-Bhimunipatnam corridor get potable water free from saline water pollution it has been decided to first identify the patches of fresh and saline water sources and then categorize them quality wise. As a part of this important societal problem, a hydrogeochemical study has been carried out in Visakhapatnam and Bhimunipatnam district situated along the East coast of India to primarily identify the influence of saline water on fresh water aquifers and then categorize quality wise the suitability of groundwater for drinking and domestic purposes. Limited investigations in this coastal region have reported signs of seawater intrusion, pollution due to industrial effluents and natural weathering process. A total of 63 groundwater samples have been collected and analyzed for major anions and cations for post and pre-monsoon seasons of 2015. The geochemical parameters have been compared with World and Indian quality standards. The study has revealed that most of the samples are suitable for drinking purpose. Gibb’s plot revealed that the mechanisms responsible for controlling the chemical composition of the groundwater include both the rock water interaction and evaporation. The correlation of laboratory analysis of different proportions (%) of seawater to freshwater and to the field electrical conductivity indicates that 84% of samples are of type I category (low salts) and are safe for drinking. Out of the remaining, 13% of samples belong to type II (medium salts) and 3% to Type III (high salts) categories, respectively. The ionic ratios show that 8% of the samples indicate the transformation of the fresh groundwater aquifer system to saline.
Key words: Groundwater, Visakhapatnam-Bhimunipatnam, hydro-geochemical study, anions and cations, weathering, seawater intrusion, electrical conductivity.
7
Estimation of Total and Unit Stream Power along Bhagirathi River, Uttarakhand, IndiaSatya Prakash* and Rajesh Kumar1
1Centre for the Study of Regional Development, School of Social Sciences,
Jawaharlal Nehru University, New Delhi-110067, India
*Corresponding Author: satyapthakur@gmail.comABSTRACT
Stream power is mostly used as an indicator for investigating engineering structures along the river banks. It has a considerable influence on forms and processes of the river system. It also provides information regarding the potential of a river to move sediments. The objective of this study is to estimate the total and unit stream power of Bhagirathi River and thereby to find the relationship of average unit stream power with landslides along the river. In this study, the longitudinal profile of the Bhagirathi River has been drawn using filled ASTER DEM in GIS environment. The smoothed longitudinal profile has been further used for the computation of slope at 1 km interval. The power function relationship has been established between peak discharge and drainage area to estimate peak discharge for ungauged points along the Bhagirathi River at 1 km interval. Channel slope, the specific weight of water and discharge are vital parameters for stream power computation. Total and unit stream power have been estimated at 1 km interval along the Bhagirathi River. The slope is found to be 0.04 and 0.0014 mm-1 along the extreme upper and lower reaches of the Bhagirathi River, respectively. Due to the steep slope, the total and unit stream power profiles show high peaks in the mid-stream of the Bhagirathi. The fluctuations in the total stream power along the Bhagirathi River signify the variation in sub-regional slope as well as in discharge contributing areas. The unit stream power is high in the upper reaches of the river, and it shows decreasing trend in downstream. Unit stream power mainly governs the bar deposition in the active channel of the Bhagirathi River. The association between average unit stream power and number of exposures/landslides has been found to be statistically significant at the 0.01 level of significance.
Keywords: Longitudinal profile, Total stream power, Unit stream power, Bhagirathi River, ASTER DEM, GIS, Polymodal distribution.
8
Petrology, mineral chemistry and geochemistry of the chromian muscovite bearing quartzite in the Neoarchean Veligallu schist belt, eastern Dharwar craton, IndiaTarun C. Khanna1*and V. V. Sesha Sai2
1CSIR-National Geophysical Research Institute, Hyderabad-07, India
2 Petrology Division, Geological Survey of India, Hyderabad-68, India
*Corresponding Author: khannangri@ngri.res.inABSTRACT
In the present study, we report on the petrography, mineral chemistry and geochemistry of the chromian muscovite bearing quartzite in the Neoarchean Veligallu schist belt (VSB), eastern Dharwar craton, India. The quartzites appear as greenish isolated outcops within the metavolcanic sequences in the north-central part of the VSB. Mineralogically, the rock consists of quartz and subordinate muscovite, while zircon and rutile are noticed as accessory heavy minerals. Mineralogical composition of the muscovite indicates a maximum chrome content upto 4000 ppm. The average (n= 5) bulk-rock geochemical compositions consist of > 85 wt. % SiO2, ~2.2 wt. % K2O, ~0.21 wt. % Na2O, ~6.3 wt. % Al2O3, ~0.22 wt. % TiO2, and ~0.29 wt. % MgO contents. Archean upper continental crust normalized trace element patterns indicate positive Zr and Hf anomalies, consistent with the accumulation of zircon in the rock. Petrographic observations are inconsistent with a metamorphic origin for the enrichment of chrome in these quartzites. Geochemical atttributes involving Ni-V-Th systematics suggest contribution of Ni from ultramafic rocks in the source of the protolith. Alternatively, we infer a hydrothermal origin for the enrichment of chrome in the muscovite bearing Veligallu quartzites. The geochemical compositions, for instance, high silica and the absence of Fe2O3 in the rocks indicate that the protolith was derived from the weathering of a felsic source, presumably an archean granite / TTG.
Key words: Cr-muscovite, Quartzite, Neoarchean, Veligallu schist belt, eastern Dharwar craton, India.
9
Long range forecast and development of a weak southwest monsoon during 2017- Pt. II: DevelopmentOnkari Prasad1*, O.P. Singh2 and K. Prasad3
143, Ritu Apartments, A-4 Paschim Vihar, New Delhi-110063
2 B44, First Floor,Parshvnath Paradise,Mohan Nagar,Ghaziabad(U.P.)-201007
3 D-104, Seema Apartments, Sector 11, Dwarka, New Delhi-110085
*Corresponding Author: prasadonkari123@yahoo.inABSTRACT
2017 southwest monsoon was unique in several respects: (i) It was a weak monsoon, not over India alone, but over the monsoonal regions of the globe, (ii) Even with weak monsoon conditions, rainfall for India as a whole was on the higher side of normal during June by 4% (iii) Normal to above normal/excess rainfall occurred in July over different regions of India resulting in 2% above normal rainfall for the month for India as a whole, (iv) There was an intra-seasonal change in the activity of South Indian ocean Convergence Zone (SIOCZ) during the second half of the season, which was expected to bring improvement in rainfall over Central and Northwest India, but it did not happen and rainfall improved over south Peninsula, (v) Though not intense, SIOCZ remained generally active from the week ending on 5th July till the end of the season. Development of 2017 southwest monsoon has been studied with the help of OLR Total, OLR anomaly, cloudiness, daily and weekly rainfall and monthly precipitation anomaly data. It has been shown that the superimposition of intra-seasonal changes over intra-seasonal oscillation was responsible for the development of different features during 2017 monsoon as enumerated above. Further the activity of SIOCZ and rainfall distribution over India during 2017 monsoon have, once again, confirmed the validity of the results, which had formed the basis for proposing SIOCZ model of long range forecasting of monsoon rainfall in India.
Key words: Southwest monsoon, South Indian Ocean Convergence Zone model, Activity index, Intra-seasonal changes, OLR total, OLR anomaly, Monsoon Trough, Long range forecast, Updates.
10
Severe cyclonic storm JAL, air-sea interaction perspectives and floods along Andhra Pradesh-Tamilnadu coastG.R. Chinthalu*, T. Dharmaraj, M.N. Patil, A.R. Dhakate, S.D. Pawar and Siingh D
Indian Institute of Tropical Meteorology,
Dr. Homi Bhabha Road, Pashan, Pune 411 008, INDIA
*Corresponding Author: chintalu@tropmet.res.inABSTRACT
Severe cyclonic storm JAL that devastated many Asian countries including southern east coast of India during 4-8 November 2010, evolved from a low pressure area in the South China Sea, near the eastern coast of Borneo, on 28 October 2010. Moving northwestward, the low pressure area emerged in the Bay of Bengal and concentrated in to a tropical depression on 4th November and into a severe cyclonic storm in the early morning of 6th. It produced very heavy rains causing severe floods and damage to life and property over parts of Malaysia, Thailand,Sri Lanka and India. It crossed the east-coast of India on November 7 north of Chennai, 13.3°N and 80.3°E and landfall near Nellore. The system attained a maximum intensity of T3.5. Coupled ocean-atmospheric processes have been examined to understand the unusually long track of the system and impact of floods on landfall along Andhra Pradesh- Tamil Nadu coast. Analysis of daily high resolution reanalysis data in the domain, 0-25°N, 60-130°E, during 1-8 November 2010 has revealed variation of Sea Surface Temperature (SST) between 27- 31°C, cooler SST to the left of the cyclone track and wind speed between 16 to 24 ms-1. Satellite derived 3-hourly daily accumulated precipitation varied between 36 to 90 mm. Heavy rainfall was confined to the coastal hilly regions and rainfall was very low over the open ocean along the cyclone track. This had resulted in only a marginal cooling of SST, which had helped in the maintenance of sensible and latent heat fluxes. Significantly warm SST had provided continuous supply of moisture for the sustenance and unusually long travel of the system over sea.
Key words: Severe cyclonic storm JAL, Air- sea interactions, floods, damage.
11
Meteorological conditions for development of heat wave over Coastal Andhra Pradesh and TelanganaCharan Singh* and S. V. J. Kumar
India Meteorological Department, Mausam Bhavan, Lodi Road, New Delhi-110003
*Corresponding Author: csingh1964@gmail.comABSTRACT
Heat waves are one of the weather hazards affecting different regions of India with varying intensity. Beforehand knowledge of the meteorological conditions favorable for the occurrence of heat wave/severe heat wave conditions over a given region/state is required for issuing warnings. Reasonably accurate meteorological conditions are now available from dynamical models, several days in advance, and the same could be used for issuing warnings about likely development of heat wave/severe heat wave condition. In the recent past, Andhra Pradesh and Telangana had been affected by severe heat wave conditions for several days in continuation. In the present study meteorological conditions associated with the heat waves over coastal Andhra Pradesh and Telangana during May 2015 have been detailed. The analysis of meteorological conditions has shown that the severe heat wave conditions during the year had resulted due to advection of dry air from northwest over a prolonged period of time when skies were cloud-free, soil moisture was low and there was an absence of development of strong sea breeze in the afternoons.
Key words: Meteorological conditions, Heat waves, Sea breeze, Soil moisture, Warnings about heat waves.
12
FORTRAN code to convert resistivity Vertical Electrical Sounding data to RES2DINV formatR. Rajesh* and R.K.Tiwari
CSIR-NGRI, Hyderabad, India,
* Corresponding Author: rekapalli@gmail.comABSTRACT
We present the conversion of multiple vertical electrical resistivity sounding data measured at equal intervals along a profile into ‘*.DAT’ 2D data file, which is compatible with Res2D.INV to obtain 2D resistivity inverse model. For this, we have developed a FORTRAN code. We applied the code on real time resistivity sounding data acquired using Dipole-Dipole array and obtained the 2D data file. Finally, we have inverted the converted 2D data using Res2D.INV program to obtain the 2D resistivity subsurface model. Thus, the code helps to generate the 2D resistivity model of the subsurface from sounding data obtained using four electrode setup (Wenner, Dipole-Dipole, Schlumberger arrays), where the usage of advanced equipment and financial supports are limited, to provide two dimensional interpretation on groundwater resources, soil pollution etc. The conversion and analysis of available past resistivity data helps to study the time-lapse resistivity changes through the comparison of present data within the limits of data errors and resolutions. The weathered water bearing zone and fractures identified on the 2D resistivity inverse model obtained from the converted 1D sounding data from Boneikela village, Sundargarh district, Orissa clearly matches with regional hydrogeology.
Key words: Vertical Electrical Sounding, Res2D.INV, 2D inverse model, FORTRAN code, Groundwater, Time lapse resistivity.
Technical Note
Endeavours in seismic monitoring of oceans through drifting network with development of a New Generation Mobile Earthquake Recorder in Marine Areas by Independent Divers---The Son-O-MERMAID
Raja Acharya
Indian Meteorological Department, Regional Meteorological Centre, Kolkata (Ministry of Earth science)
Email: raja.acharya2011@gmail.com
