039064   MISHRA A K, MANISH K (Ocean Studies and Marine Biology Dep, Pondicherry Univ, Andaman and Nicobar Islands, Email: amritkumarmishra@gmail.com) : Andaman mangrove sediments: Source of nutrients and sink of heavy metals. Indian J Geo-Mar Sci 2020, 49(1), 156-66.

Andaman Islands (AI) of India is a biodiversity hotspot of mangroves but biogeochemical dynamics of AI is less understood. We collected sediment samples from four AI mangrove sites and one site without mangroves for nutrients and trace metal analysis. Samples were collected from each site at the inlet of seawater (Zone A) and the other 500 m into the mangrove creek (Zone B). Nutrients (sulphate, ammonium, nitrite and nitrate) level, organic matter (OM) and carbon content were higher at Zone B of mangrove ecosystem due to the higher OM content from mangrove leaf litter decomposition and microbial degradation. Metal (Pb & Cd) content of zones with and without mangroves were similar and Igeo values indicated moderate contamination of mangrove zones of AI due to lack of anthropogenic pollution. Our results suggest mangrove ecosystems of AI are uncontaminated from heavy metals and are source of nutrients to the oligotrophic coastal ecosystems of Andaman Sea.

6 illus, 1 table, 82 ref

039063   SHARIATMADARI N, NOROUZI M, JAVADI A S, ALIZADEH M (Iran Univ of Science and Technology, Iran, Email: Shariatmadari@iust.ac.ir) : Geotechnical behaviour of the carbonate sand-granulated tire mixture. Indian J Geo-Mar Sci 2020, 49(1), 149-55.

Carbonate sand-tire mixture is used in this research as a soil improvement method to address the environmental problems regarding the accumulation of scrap tires in coastal areas. The stress-strain behaviour, internal friction angle, and the particle breakage of the carbonate sand-tire mixture are studied, and the results are compared to that of pure carbonate sand. The results revealed that the addition of the granulated tires to the carbonate sand changed its behaviour. The addition of granulated tires resulted in a decrease of both the friction angle and the quantity of particle breakage.

11 illus, 1 table, 30 ref

039050   MAGESHKUMAR P, VENNILA G (Civil Engineering Dep, K.S. Rangasamy Coll of Technology, Namakkal- 637 215, Email: mageshee@gmail.com) : Assessment of errors in water quality data using ion balancing methods - A case study from Cauvery River, South India. Indian J Geo-Mar Sci 2020, 49(1), 57-62.

This paper provides an insight into the reliability checking options through error assessment for analytical water quality data with a case study, which will be useful for the researchers working on the analytical chemistry. The reliability of chemical analysis has to be verified in a scientific manner before the data is used for further interpretation. The distributions of data values were presented using box plots. The four ion balancing methods, namely anion-cation balance, measured total dissolved solids (TDS) Vs calculated TDS, measured electrical conductivity (EC) Vs ion sums and calculated TDS to EC ratio were applied on the surface water quality data of Cauvery River in Erode region, Tamil Nadu, India. It was found that the errors of the analysis were within the acceptable limits except 14 samples in percentage difference calculations.

1 illus, 3 tables, 13 ref

039047   CHARI N V H K, VENKATESWARARAO C, MURALIKRISHNA R, SIVAKRISHNA K (Physical Chemistry Dep, Andhra Univ, Visakhapatnam- 530 003, Email: harinaroju@rediffmail.com) : Variation of hydrochemical parameters with reference to geomorphological features in Godavari estuary, India. Indian J Geo-Mar Sci 2020, 49(1), 24-33.

In this study, seasonal observations of hydrochemical parameters were measured in the estuarine regions of Gautami Godavari (GGE) and Vasishta Godavari (VGE), which are surrounded by extensive mangrove swamps and closely spaced beach ridge-swale complex, respectively. A significant vertical stratification in the water column showed in the VGE region due to the strong influence of saline water intrusion. NO₂- -N was higher and NO₃- -N was lower in VGE during the end of the post monsoon season with reference to excretion by phytoplankton and up take during the process of primary production respectively, which is also supported by higher concentrations of Chlorophyll a. Nutrients (NO₃- -N, PO₄³—P and SiO₄^2--Si) showed conservative behaviour with salinity in GGE, whereas, in the case of VGE absence of this is due to intrusion of saline water was significantly higher.

6 illus, 2 tables, 23 ref

039046   PALANICHAMY M, SANKARALINGAM R, NARAYANASAMY (Civil Engineering Dep, Kalasalingam Academy of Research and Education, Krishnankoil- 626 126, Email: snrcivil@aamec.edu.in) : Statistical studies on rainfall and time-based deviations in precipitation trends in Vaigai River Basin, TN state, India. Indian J Geo-Mar Sci 2020, 49(1), 15-23.

Food shortage and water shortage remains the most critical issues throughout the world. Understanding the variability in rainfall will help to make predictions about the rainfall patterns as well as addressing the issues of food-water-energy nexus.Herein, a trend analysis of rainfall was carried out in selected seven rainfall stations of Vaigai river basin in Tamil Nadu state, India. Statistical trend analysis was carried out, to observe the trend pattern for the period from 1959 to 2016. To determine the trend of rainfall, non-parametric Mann-Kend all test and Spearman Rho tests were used. This investigation provides insights about precipitation trends during annual, post-monsoon, pre-monsoon periods. These findings will provide clues for developing efficient water management systems using different simulation techniques and artificial intelligence approaches.

9 illus, 12 tables, 19 ref

039045   GUPTA A, VIJAY R, KUMAR R (CSIR- National Environmental Engineering Research Institute, Nagpur- 440 020, Email: r_vijay@neeri.res.in]) : Hydrodynamic and advection-dispersion simulation of cool seawater discharges from an LNG facility. Indian J Geo-Mar Sci 2020, 49(1), 7-14.

The impact of cool seawater discharge in the coastal waters from a Liquefied Natural Gas (LNG) plant has been simulated using MIKE21. In this work, hydrodynamics conditions of the coastal waters were calibrated and corroborated to predict the cool seawater discharge under two plant design scenarios by selecting flow rate 15 m³/s and 10 m³/s with a temperature drop of 5 °C and 7 °C, respectively. The simulations were carried out under different scenarios, to arrive at the best possible case to minimize the potential impact on the coastal environment. Both the simulated scenarios complied with the available World Bank guidelines for LNG facilities. However, the designed scenario of flow rate 10 m³/s with a temperature drop of 7 °C between inlet and outlet presents a better choice as it reduces the pumping power of seawater intake. As there are no Indian guidelines for cool seawater discharges from LNG plant, the present work can support the policymakers and regulators to formulate coherent discharge standards.

6 illus, 23 ref

006526   GNANASEELAN C, CHOWDARY J S (Indian Institute of Tropical Meteorology, Pune – 411 008, Email: seelan@tropmet.res.in) : The Indo-Western Pacific climate variability and the impacts on Indian summer monsoon: Two decades of advancement in India. MAUSAM 2019, 70(4), 731-52.

Interannual climate variations over the Indo-Pacific region are mostly dominated by El Niño Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), subtropical Northwest Pacific circulation and Indo-Pacific Ocean Capacitor (IPOC) Mode. The present manuscript reviews and summarizes the work mostly carried out in our lab on the weather and climate variability with a special emphasis on Indian Ocean, western north Pacific and Indian Summer Monsoon Rainfall (ISMR). Here we have provided a synthesis on the Indian Ocean modes, physical processes, biases in models, interaction with Pacific, and their impact on ISMR and also unraveled some important mechanisms. A new mode of variability in the Tropical Indian Ocean (TIO) subsurface temperature was recently reported and which is found to have strong impact on the regional climate variability. We have also demonstrated the formation mechanism using in situ observation, reanalysis, ocean models and coupled ocean atmosphere models. Intense basin wide TIO warming during El Niño and IOD co-occurrence years and the dynamic processes behind maintaining this warming are explored. We have shown for the first time that a pronounced up-westward propagation of subsurface warming along the sloping mean thermocline and westward propagation of Barrier Layers corroborated by downwelling Rossby waves excited by equatorial zonal wind anomalies during El Niño-IOD co-occurring years. A robust positive feedback between SST warming and Barrier Layer development lead to changes in air-sea interactions over the western TIO, which is a region crucial for ISMR prediction and development of MJO. Several science questions leading to the understanding of ENSO and non-ENSO teleconnections to ISMR with more emphasis on decay phase of El Niño and the Indo-western Pacific Ocean capacitor (IPOC) mode and Pacific Japan (PJ) pattern are addressed. We have also explored the influence of the Pacific-Japan pattern (PJ) on ISMR and proposed the possible physical linkages through coupled (ocean-atmospheric) and uncoupled (atmospheric) pathways and showed that in response to the PJ pattern the rainfall over the southern India enhances due to northwestward propagating Rossby waves corroborated by low level convergence in the southern flank of westward extended western north Pacific (WNP) anticyclone. On the other hand, it is found that westward propagating atmospheric cold Rossby wave as a response to suppressed convection over the western north Pacific region induced moisture divergence associated with IPOC mode and downward motion play important role in maintaining negative rainfall anomalies over the monsoon trough region. The coupled interaction between Indian Ocean basin mode, asymmetric mode in the TIO, northwest Pacific circulation etc. paved way for renewed understanding of monsoon teleconnections. We have carried out several ocean model and coupled model simulations and sensitivity experiments to understand the processes responsible for the Indian Ocean variability, the ISMR variability and the teleconnections. The efforts were also made to understand the ocean biases in the coupled model used for monsoon forecast in India. While examining ocean state in coupled models, we noted that they exhibit too much surface cooling and subsurface warming over the TIO. Our work for the first time revealed that the enhanced vertical mixing by strong vertical shear of horizontal currents is primarily responsible for TIO subsurface warming and feeds back to surface cooling in coupled models. The misrepresentation of ENSO-monsoon teleconnection and ENSO-Indian Ocean teleconnection in the monsoon forecast model is also addressed in detail with a view to improve the forecasting system. We have shown that most of the models failed to represent ENSO-Monsoon teleconnections, mainly due to unrealistic westward extension of SST warming/cooling associated with El Niño/La Niña, changes in WNP circulation and TIO SST response. These contributions towards climate variability would be useful to further development in coupled models and improvisations. Developing a predictive understanding of regional climate including the new modes of variability is a grand challenge for research community and our two decades of contributions were nailing towards these aspects.

12 illus, 116 ref

006542   SRINIVASAN G, AGARWAL A, SAWANT M (Asian Institute of Technology, Bangkok, Thailand, Email: srini@rimes.int) : Enhancing climate services in south Asia. MAUSAM 2019, 70(4), 725-30.

Developing climate services in South Asian countries is important to build resilience to current climate variations and future climate change. National Meteorological and Hydrological Services (NMHSs) of the South Asian countries were supported by the World Meteorological Organization (WMO) and RIMES to enhance climate services. The work focused on established/strengthen user interface platform, build the capacity of user to use climate information in decision making, engage with users to promote climate information and initiate the policy process for sustain the climate service for long term. The implementation of the South Asian Climate Outlook Forum (at regional level) and National Climate Outlook Forum/ monsoon forums (at National Level) were two important tools used for establishment/strengthening user interface platform in south Asia. The country-specific training curriculum was also developed and implemented, focused on climate information utilization for impact assessment, climate projection, risk management, diseases surveillance and hydrological management. To fulfil the recommendation, received through user interface platform such as NCOF and SASCOF, field level demonstration and web-based decision support systems (DSS) were developed in the selected countries. The various experience, lesson learnt and needs to sustain the climate services has been conveyed to the policy makers through various meetings, visits and discussion during events such as SASCOF and monsoon forums.

1 illus, 2 ref

006530   KISHTAWAL C M (Indian Space Research Organization, Ahmedabad – 380 015, Email: cmk307@rediffmail.com) : Use of satellite observations for weather prediction. MAUSAM 2019, 70(4), 691-708.

Meteorological satellites have evolved significantly during past six decades and now the observations from these satellites are indispensable for weather monitoring and prediction. These observations are critical for monitoring the development of weather e.g., the movement of tropical storms and severe weather and provide atmospheric measurements that are ingested into the numerical on (NWP) models for accurate weather prediction. This article describes different types of meteorological satellites, sensors and the atmospheric observations from these sensors. Results of Observation System Simulation Studies (OSSE) using satellite data are briefly described to show the relative impact of observations from satellite sensors and conventional ground based observation network.

11 illus, 43 ref

006533   MOHANTY U C, NAYAK H P, SINHA P, OSURI K K, NIYOGI D (Earth and Atmospheric Sciences Dep, National Institute of Technology, Odisha –769 008, Email: ucmohanty@gmail.com) : Land surface processes over Indian summer monsoon region: A review. MAUSAM 2019, 70(4), 691-708.

The earth’s surface continuously interacts with the overlying atmosphere through the exchange of mass, moisture and momentum, thereby altering the energy and water cycles. Through this, the earth's surface affects regional energetics, which via scale-interaction influences weather and climate systems. The land surface feedbacks are dominant over the Indian Monsoon Region (IMR) and exert impact on the atmospheric responses such as convection and precipitation through boundary layer coupling. As a result, the land surface processes associated with Indian Summer Monsoon (ISM) need to be understood and realistically represented in Numerical Weather Prediction (NWP) and regional/global climate models. The ISM is a multiscale system influenced by the boundary forcing from both the continent and tropical oceans, as well as from various boundary layer feedback mechanism. The ISM and associated rainfall is a complex system owing to non-linear interaction between large-scale fields and small-scale convective activities. The ISM is notably influenced by the local and regional scale land surface interactions. This paper reviews the recent developments related to land surface processes and their application to ISM process studies. The evolution of land surface models, state-of-art Land Data Assimilation Systems (LDAS) and their applications in NWP models are discussed.

10 illus, 117 ref

006527   GOPALAKRISHNAN S G, OSURI K K, MARKS F D, MOHANTY U C (NIT Rourkela, Odisha- 769 008, Email: sundararaman.g.gopalakrishnan@noaa.gov) : An inner-core analysis of the axisymmetric and asymmetric intensification of tropical cyclones: Influence of shear. MAUSAM 2019, 70(4), 667-90.

The state-of-the-art in intensity forecasting is provided using the Hurricane Weather Research and Forecasting (HWRF) modeling system as the basis. A brief review of existing axisymmetric theory for the intensification of tropical cyclones (TCs) is also provided. Two cloud-resolving simulations from HWRF, one from an idealized case and another from a retrospective forecast of Super Cyclone Phalin (2013), are used to understand the axisymmetric, rapid intensification (RI) process. However, TCs are rarely axisymmetric. The asymmetric structure in the inner core of a TC may be generated by both internal dynamics and external forcing due to environmental factors such as shear and moisture. We use a retrospective HWRF run from Atlantic Hurricane Earl (2010) to understand the role of shear-induced asymmetries on the RI of TCs. We seek to address the following questions: How do TCs rapidly intensify in a sheared environment? What is the role of eddy fluxes on TC intensification? Is the well-accepted theoretical framework of TC intensification still valid for sheared storms undergoing RI? Our findings show that eddy radial vorticity fluxes play a significant role in controlling TC intensity changes in sheared storms. In the case of Earl, despite persistent environmental shear and a lack of symmetric convection, a positive eddy vorticity flux in the middle to upper troposphere created by mesoscale convective complexes had a profound influence in accelerating the TC spin-up process. RI does not occur until persistent convective bursts and the collocated vertical vorticity are concentrated in the downshear-left quadrant about 50 km from the surface center, followed by the propagation of these complexes in an upshear direction. When convective bursts reach the upshear-left quadrant, a nearly symmetric pattern of eddy radial vorticity flux surrounds the center, indicating vorticity anomalies have merged to create a stronger mean vortex wherein the upper and lower level circulations are better aligned. This process is different from that of an idealized vortex. An idealized vortex intensifies in a shear-free environment where individual vortical hot plumes converge and stretch ambient low-level vorticity into a small-scale anomaly and multiple mergers of these plumes lead to a single stronger vortex in a vorticity rich environment. In the idealized case, the major spin-up of the vortex occurs in the TC boundary layer and eyewall region, while spin-up in the case of Earl appears to be top-down during the early stages of RI. Nevertheless, evidence of stronger spin-up is observed in the boundary layer after Earl’s initial RI phase. Although a fully three-dimensional model is required to understand the real TC intensification problem, when viewed from an axially-averaged framework, the basic axisymmetric theory of intensification is still valid for all cases.

12 illus, 97 ref

006534   MOHAPATRA M, SHARMA M (India Meteorological Dep, New Delhi – 110 003) : Cyclone warning services in India during recent years: A review. MAUSAM 2019, 70(4), 635-6.

India experiences various types of natural hazards including cyclones, floods, droughts, earthquake, landslides, heat wave, cold wave, thunder squalls and tornadoes. Most of these hazards (about 80%) are hydrometeorological in nature. Among the hydrometeorological hazards, the cyclones over the North Indian Ocean (NIO) pose a potential threat to coastal population as well as marine community of the region. The risk management of the cyclones depends on several factors including (i) hazard & vulnerability analysis, (ii) preparedness & planning, (iii) early warning, (iv) prevention and mitigation. The early warning component includes (i) skill in monitoring and prediction, (ii) effective warning products generation and dissemination, (iii) coordination with disaster response units and (iv) public awareness & perception about the credibility of early warning of cyclone issued by India Meteorological Department (IMD). Though there have been significant improvement in cyclone monitoring and warning system in recent years due to modernization programme of Ministry of Earth Sciences (MoES)/IMD and policy frame work of Govt of India, there is still scope for improvement at state and district level in terms of (i) improving the mesoscale hazard detection and monitoring in association with cyclone, (ii) improving the spatial and temporal scale of forecasts through technological upgradation, (iii) warning communication to last mile and disaster managers through state of art technology, (iv) developing synergized standard operation procedure among the early warning agencies and user agencies and (v) real time impact based forecast and risk based warning. All these aspects have been discussed with special emphasis on climatological characteristics (spatial and temporal distribution and intensity etc.), damage potential, modeling and prediction, Prediction skills, information dissemination mechanisms, socio-economic impacts, achievements in recent years, existing gap areas and future scope.

16 illus, 2 tables, 93 ref

006525   GHOSH P, MANDAL H, SIRISHA B, SEN U, GOSWAMI S, KIRAN N V R (Geological Survey of India, Hyderabad- 500 068) : A modified acid digestion method for analysis of gold in geological samples: A comparative study. MAPAN- J Metrol Soc India 2019, 34(4), 551–8.

Quantification of gold in geological samples using fire-assay technique is a well-established and recommended method worldwide. However, the method is laborious, complicated, sluggish, and health hazardous. Only a well-trained chemist can perform gold analysis through fire assay routinely. Although classical aqua regia digestion for determination of gold yields high throughput, this method too has disadvantages of sample nature dependency, thus brings down the recovery levels. Herein, we report a modified aqua regia digestion method, followed by solvent extraction using methyl isobutyl ketone for the accurate and precise estimation of Au in variety of geological samples of different genre in broad concentration range. Roasting of sample was avoided and excess of aqua regia (6 times or higher than of sample weight) was used to bring all gold in aqueous phase. This method was applied to soil and rock samples and the results obtained were compared with conventional fire-assay technique. The analytical results for international reference materials of gold (SRM/CRM) measured by the proposed method were in close agreement with those obtained by fire-assay method and recommended values. Very low detection limits were achieved in the proposed method (1 ng/g by GF-AAS and 100 ng/g in F-AAS). This method also works satisfactorily at moderately higher concentration of gold in rock samples, at least up to 15 ppm. Thus fire-assay technique may be substituted by the proposed method for detection of Au in 10 ppb–15 ppm concentration range in the geological samples mentioned under present study.

3 illus, 34 ref

006548   WOUTERS M J, MARAIS E L (National Measurement Institute, Lindfield, Australia) : GPS-based time transfer using low-cost receivers. MAPAN- J Metrol Soc India 2019, 34(4), 521–8.

GPS-based time transfer can be used to establish a traceable link between a national time standard and a remote user’s standard. Equipment cost can be a consideration in such applications, and the GPS receiver used can be a significant component of this cost. We consider the use of low-cost timing receivers in time transfer, establishing the requirements for such receivers. Three suitable receivers are characterized, using software we have written for the Open Traceable Time Platform, an open-source project developing a system for legally traceable time and frequency. The tested receivers were found to be suitable for all but the most demanding applications.

6 illus, 14 ref

006522   CHAND B, KUNIYAL J C, CHAND R (G.B. Pant National Institute of Himalayan Environment and Sustainable, Uttarakhand- 263 643) : Ambient air quality and its sources surrounding to hydropower projects in the Satluj Basin, Northwestern Himalaya, India. MAPAN- J Metrol Soc India 2019, 34(4), 495–510.

Ambient air quality in terms of particulate matter < 10 µ (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and ammonia (NH₃) was monitored in the upper Satluj basin under-construction stage of Shongtong-Karcham (450 MW) and commissioned stage of Rampur (412 MW) hydropower projects. PM₁₀ ranged from 102.8 to 111.9 µg m⁻³ with a mean of 106.4 ± 1.2 µg m⁻³ in summer season at Shongtong-Karcham, while at Rampur project it was found from 17.8 to 65.5 µg m⁻³ with a mean of 50.9 ± 6.1 µg m⁻³. Particulate pollution is high under a construction project stage as compared to a commissioned project. While gaseous pollutants like SO₂ (8.2 ± 1 µg m⁻³), NO₂ (10.2 ± 0.8 µg m⁻³) and NH₃ (11.2 ± 1 µg m⁻³) were found relatively high at Rampur compared to Shongtong-Karcham where SO₂ (7.9 ± 0.6 µg m⁻³), NO₂ (4.8 ± 0.6 µg m⁻³) and NH₃ (8.9 ± 1.1 µg m⁻³) were found relatively low. The particulate pollutants crossed its permissible limit (100 µg m⁻³) as set by National Ambient Air Quality Standards, India, while gaseous pollutants were under permissible limit. HYSPLIT and concentrated weighted trajectory analysis indicate that hydropower project activities have been major local sources of particulate (> 80 µg m⁻³) and gaseous pollutants, although overall air quality index is good (0–50).

11 illus, 31 ref

006532   MANDAL G, KUMAR A, MANDAL S, SHARMA D C, KUMAR M (CSIR - National Physical Laboratory, Delhi- 110 012) : Volume measurement of large volumetric vessel using tap water. MAPAN- J Metrol Soc India 2019, 34(4), 487–93.

Being a National Metrology Institute (NMI) of India, CSIR-National Physical Laboratory, India (NPLI), provides calibration services to the industries to improve the quality of products. In the last couple of years, NPLI has provided number of calibration services of volumetric vessels up to 2000 L (unique facility in India) to the petroleum industries, flow meter manufacturing industries, etc. In general, for the calibration of volumetric instruments, distilled water is used as the medium but in the case of large volumetric vessels (say 2000 L), the use of distilled water is not practical. Hence, tap water is used and every time the density of tap water is measured against distilled water to improve the accuracy of the measurement. In this process, we have achieved measurement uncertainty less than 50 mL in 2000 L. But due to influencing factors of environmental conditions of laboratory, change of density of supplied tap water, conversion factors of tap water and distilled water in desire temperature, we have restricted our calibration and measurement capability (CMC) up to 100 mL in 2000 L. In this paper, we have discussed the detailed procedure of volume measurement of 2000-L volumetric vessel and its associated uncertainty calculations using gravimetric method.

2 illus, 11 ref

006524   GALLIANA F, LANZILLOTTI M (Innovation and Metrology Services Dep, National Institute of Metrological Research, Turin, Italy) : Report of a multilateral accurate measurement comparison on a high-precision multimeter to evaluate the traceability transfer from INRIM in the field of low-frequency electrical quantities. MAPAN- J Metrol Soc India 2019, 34(4), 473–8.

As the calibration activity of modern electrical secondary laboratories operating in the five low-frequency quantities is carried out by means of high-precision digital multimeters (DMMs), it is of fundamental importance for their correct technical surveillance through suitable inter-laboratory comparisons (ILCs). The laboratory for calibration of multifunction electrical instruments of the National Institute of Metrology Research (INRIM-Lab) provides bilateral and multilateral ILCs involving high-precision DMMs to check the measurement capabilities of electrical laboratories. In particular, this paper deals with the last multilateral ILC that INRIM-Lab provided and carried out as reference measurements’ provider to which took part twelve Italian-accredited laboratories divided into two loops. The ILC was involved in a high-precision 8.5 digit high-precision DMM to be verified in a grid of about forty measurement points. The 2σ relative uncertainties of the INRIM-Lab calibrations ranged from 1.6 × 10⁻⁶ to 1.5 × 10⁻⁴, while those of the laboratories ranged from 2.0 × 10⁻⁶ to 2.2 × 10⁻³. The ILC had satisfactory results confirming the correctness of both the dissemination from INRIM and the accreditation process by the Italian accreditation body for calibration laboratories.

6 illus, 16 ref

006535   NADE D P, POTDAR S S, PAWAR R P, MANE S T, CHANDRA S, TAORI A, SINGH D (Basic Sciences and Humanities Dep, Shivaji Univ, Kolhapur, Maharashtra, Email: dada.nade@gmail.com) : Total column ozone, precipitable water content and aerosol optical thickness over Atigre village, a tropical station: First observations. MAPAN- J Metrol Soc India 2019, 34(4), 451–63.

In this paper, we report first-time observations of total column ozone (TCO), aerosol optical thickness (AOT) and precipitable water content (PWC) at five different wavelengths using compact, handheld, multichannel sun photometer (Microtops II ozonometer) at Atigre village (16.74N latitude, 74.37E longitude, 604 ms altitude above sea level). The three optical filters at wavelengths 305 nm, 312 nm and 320 nm are used to detect the TCO, while two optical filters 936 nm and 1020 nm are used to detect the PWC and AOT, respectively. We have been collecting data from September 1, 2017, and 122 days are selected from September 1, 2017, to December 31, 2017, to present as first observations of TCO, AOD and PWC. The mean values of TCO, AOT and PWC are found to be 261.2 (± 9.22) DU, 0.25 (± 0.04) and 1.98 (± 0.79) cm, respectively, during this period. The TCO measurements taken by the Microtops II ozonometer are compared with the ozone monitoring instrument satellite data over Atigre. We found that PWC and AOT values are negatively correlated (- 0.54) during monsoon season, while they show positive correlation (0.63) during other seasons with 90% significance level. The diurnal variation of TCO, PWC and AOT differ in monsoon and the post-monsoon season.

7 illus, 4 tables, 50 ref

006543   SUHAIL M, KHAN M S, FARIDI R A (Physics Dep, Majmaah Univ, Al-Majmaah 11952, Saudi Arabia, Email: ms.khan@mu.edu.sa) : Assessment of urban heat islands effect and land surface temperature of Noida, India by using landsat satellite data. MAPAN- J Metrol Soc India 2019, 34(4), 431–41.

The urbanisation is a process of change in land use by construction activities. Therefore, during construction, uses of low albedo materials give rise in heat absorption capacity that becomes the primary cause of alteration of local climate. Additionally, alteration of land use, viz. conversion of vegetation/forested land into urban built-up land and establishment of heavy industrial units contributes pertinently in local heat budget which leads to the formation of urban heat islands (UHIs). Therefore, the adverse impact of UHIs affected not only ecology and local climate but also socioeconomic setups. In the present work, spatial distribution of UHIs and their causal relationship with land use over NOIDA (New Okhla Industrial Development Authority) city has reported. The data pertaining to study was collected from Landsat8 OLI–TIRS (operational land imager and thermal infrared sensor) sensor. The results show that two clusters were developed in north and mid-east part of the city due to concentration of high-density building and industrial units. It is recommended that development authority should take environmental concern into consideration before planning industrial land use.

4 illus, 2 tables, 82 ref

006549   ZAFER A, YADAV S, SHARMA N D, KUMAR A, ASWAL D K (National Physical Laboratory, New Delhi- 110 012, Email: syadav@nplindia.org) : Economic impact studies of pressure and vacuum metrology at CSIR-NPL, India. MAPAN- J Metrol Soc India 2019, 34(4), 421–9.

Measurement standards and metrological activities provide scientific and metrological infrastructure in the country. The Pressure and Vacuum Metrology (PVM) activity has a major role in national and international metrological research and development. The PVM group is successfully providing national calibration and measurement services and fulfilling its national duty as per the mandate of CSIR-National Physical Laboratory (CSIR-NPL). Since last 35 years, no significant efforts were made to assess socio-economic impact of the services provided. Such impact studies are carried out by several National Metrology Institutes, but in India it is still an unexplored area so far. This motivated us to carry out the impact assessment, and present paper is an attempt made in this direction. Systematic studies of the contribution of PVM, established at CSIR-NPL, on national industrial growth and economy, are carried out by assessment of impact. The aim of the present paper is to present the summary of the results thus obtained which is based on the investment made over the years and the estimated benefits to the users. The studies are based on some industrial survey, personal interviews and interactions with stakeholders and sampling of services provided over the years. An overall social rate of return, an indicator of system efficiency, is found to be 180% which is quite high as compared to the present rate of return (8%). This indicates that the PVM activity is quite efficient, and future investment in the activity is safe and would provide excellent returns. The studies are very useful for broader understanding of the economic benefits of PVM and to improve understanding of the decision and policy makers about the relevance, continuation and further investment in PVM activity. This present case study may be explored and applied for other metrological fields also

6 illus, 3 tables, 17 ref

006547   TOMAR, SINGH N K (Larson & Toubro Ltd, Mumbai, Maharashtra, Email: tomar.nks@gmail.com) : Importance of geotechnical instrumentation for tunnel & cavern projects. J Eng Geo 2019, 44(1&2), 25-40.

With the manifold increase in infrastructure development throughout the world, many of innovative structures are being constructed globally. The assurance of performance of these structures during the construction and even after completion still remains a question mark. With increasing knowledge of instrumentation these days, it can be possible to periodically validate the behavior of the structure for long term also. In general when there is an excavation in rock mass, the stress filed is locally disturbed and a new set of stresses will be familiarized in the vicinity. When there is redistribution of stress is in process, the resultant strain in the form of deformation also takes place. Development in the field of geo technical engineering led to developments in various technologies for investigation, design, construction and monitoring of underground works.

11 illus, 1 table, 11 ref

006538   PATHAK, MRIDUPAM, SAINI, KUMAR S (PEMS Engineering Consultants Pvt. Ltd, Manali, Himachal Pradesh, Email: vickysaini.2007@rediffmail.com) : Geological and geotechnical challenges faced during construction of Rohtang highway tunnel. J Eng Geo 2019, 44(1&2), 19-24.

Tunnel projects in complex geological setting like the Himalayas are very unique due to the geological uncertainties and challenges to tackle them. Detailed geological investigations are an absolute necessity for effective design and construction due to large variations in the tendered and encountered rock classes witnessed here. The Seri Nalla Fault zone was encountered unexpectedly prior to its expected location. DRESS methodology proved very effective in countering the Seri Nalla zone. To counter high deformations induced in the shotcrete and lattice girders due to the high in-situ stresses, Lining Stress Controllers (LSC) are very effective.

9 illus, 3 tables, 3 ref

006546   THAKUR S N (NTPC Ltd, Chamoli, Uttarakhand, Email: girishcp2005@yahoo.co.in) : Excavation of Silt Flushing Tunnel (SFT) in difficult geological conditions. J Eng Geo 2019, 44(1&2), 18-23.

Tapovan Vishnugad Hydro Power Project (TVHPP) ,520 MW is located in the Central Crystalline rock mass.The project is run- off river scheme and under construction in the river Dhauligan gain the Chamoli district of Uttarakhand. Silt Flushing Tunnel (SFT) of 3x3.5m dia.D-shape is under construction in metabasic rock and alluvial deposit. Previously total length of SFT was 2362m, due to excavation in extremely poor rock mass condition from old outfall portal andto minimize the time of excavation length of SFTwas reduced to 1465m. The rock mass exposed in old out fall area is comprises of sheared /crushed, highly fractured & jointed quartzite .Clay filled joints are common in this area (around the old SFT out fall portal).The Dhaknala has formed a huge alluvial fan depots comprising angular to sub-angular boulders of varying size of banded streak by augengneiss,amphibolite and quartzite embedded in gritty matrix .The width of fan varies from 50 to 200 m. In-situ rock mass is absent in the area located between left bank of Dhaknala and SFT out fall (old) and huge depots mostly glacial debris /moranies/glacial outwash (over burden material) is observed .The new alignment of SFT with lesser length than the previous alignment will pass below the alluvial fan deposit and rock mass near the Dhaknala.Which will also excavated in difficult geological conditions. Out of 1465m length 880m excavation of SFT iscompleted, slope treatment for the construction of new out fall portal is completed, and excavation is started from new out fall portal. A cavity was formed at RD 59.5m, just below the nala during excavation and it was continued up to the RD 65m.The rock cover above the cavity zone varies from 46-52m.Treatment of cavity was successfully done; in this paper, challenges in progressive excavation of tunnel, excavation methods used, rock support system adopted and rock mass encountered with the emphasis on treatment of the cavity zone are described in detail.

1 illus, 1 table, 2 ref

006541   SINGH Y (Hyderabad Univ, Hyderabad– 500 046, Email: yamunasingh1957@gmail.com) : Challenges in development of river valley and hydel projects in karst terrains- broad issues. J Eng Geo 2019, 44(1&2), 1-10.

Calcareous rocks like limestones, dolomites, chalks and evaporites, are most susceptible for karstification, that is, process of solution action, by corrosive actions of meteoric, surface and subsurface waters. In fact, the corrosive action of the water is responsible for the development of various types of karstic features both on the surface and subsurface levels. Furthermore, pronounced solution action of water causes formation of dolines, which lead to development of caves passages and underground streams in karst terrains. The development of karst is intense around weak points such as intersections of joints, fractures, interstices, etc. Due to interconnected network of secondary pore systems, karst terrains pose diversified geotechnical challenges in development of river valley and hydel projects, including pressure tunnels, bridges and highways. Among others, the pronounced problems include leakages and discharges in distal places, which need to be properly identified and addressed adequately. Systematic and meticulous geotechnical assessments of karst terrains are thus imperative before development of such projects in them. Such investigations involve careful study of nature, depth, distribution and frequency of secondary pore systems and their interconnectivity by close-spaced drilling, geomorphological and geophysical surveys and geohydrological evaluations. Sealing of secondary pore systems through comprehensive pressure grouting by drilling closely-spaced bore holes is essential for checking distal leakages and discharges and degradations. Choice of depth and spacing of drilling and grouting is normally dependent up on the depth, nature and degree of karstification.

19 ref

006545   TAHAMA K, GUPTA G, BARIDE M V, PATIL J B, BARIDE A (Indian Institute of Geomagnetism, Navi Mumbai- 410 218, Email: gupta_gautam1966@yahoo.co.in) : Evaluation of groundwater potential and aquifer protective capacity of the overburden units in trap covered Dhule District, Maharashtra. Bull Pure Appl Sci-Geo 2019, 38F(2), 246-65.

This paper illustrates the determination of overburden protective capacity using vertical electrical resistivity sounding in the semi-arid hard rock terrain in Dhule district of Maharashtra. A total of 54 vertical electrical soundings (VES) were carried out using Schlumberger configuration with maximum electrode separation of 200m. The objective of this study was to locate groundwater potential zones and to evaluate the protective capacity of aquifers. Results reveal that the longitudinal conductance (S) value ranges from 0.07 to 13 mhos (siemens). The overburden protective capacity of the aquifers reveals a good to moderate rating at 92 % of the VES sites. While 2 % each represent weak and poor rating, 4 % fall in the excellent category. It is further observed that VES sites located towards north at Sirpur and northern Sindkheda sub-divisions have better protection to aquifers due to thick alluvial cover deposited by Tapi River. The transverse resistance reveals higher values towards north-west, east and south-east parts of the study area. Electrical anisotropy shows a large variation ranging from 1.028 to 6.55, implying heterogeneous and anisotropic nature of the subsurface in the study area. A positive correlation is observed between the fracture porosity and electrical anisotropy, indicating the porous zones in the study area. Further, stations with low reflection coefficient revealed higher electrical anisotropy, suggesting an inverse correlation between these two parameters. These results provide reliable information about the protective capacity of the geomaterials overlying the aquiferous unit and the fracture geometry using various geophysical indices. This is vital for planning and development of prospective water resource programs and serves as a guide for groundwater pollution control in hard-rock, semi-arid regions.

10 illus, 2 tables, 39 ref

006523   DAWAR A, DEV P (Vikram Univ, Ujjain- 456 010, Email: drpdev@yahoo.com) : Monitoring of seasonal ground water levels fluctuation in bagh study area, Dhar Distict, Madhya Pradesh, India. Bull Pure Appl Sci-Geo 2019, 38F(2), 232-45.

The present paper deals with hydrogeological setting of the Bagh study area Dhar District of Madhya Pradesh. Systematic hydrogeological survey has been carried out covering an area of 163.56 Sq. km. The well inventory involves examination of 30 dug wells in existence of study area. The data were recorded in respect of location of well, diameter, depth of well, and measurements of static water level during pos t-- and pre - monsoon periods to observe fluctuations in ground water levels. Static water levels during the post - monsoon period reveals a fluctuation range from 1.9 to 6.1 m b. g. l, and during pre - monsoon period the range of static water level varies from 3.8 to 10.7 m bgl. The fluctuations of ground water level from post - to pre - monsoon season have been observed as 1 to 7 m b.g.l. Based on static water level data, the ground water level contour maps have been prepared. The ground water level contour maps have helped in computing direction of ground water movement. The post - monsoon water level contour trend contributes in demarcations of ground water potential zones in study area. The changes in direction of ground water movement can be assigned to the lithology and structural characters. The ground water level fluctuation trends have been described as a result of excessive withdrawal of ground water.

6 illus, 6 tables, 14 ref

006531   MADHU T, KUMARI O V, KUMAR G R, REDDY E C (Geology Dep, Sree Venkateshwara Univ, Tirupathi- 517 502, Email: madhuteliki@gmail.com) : Analysis of geological factors for successful dolomite mining exploration at Venkatampalli Village, Narpala Mandal, Anantapur District, Andhra Pradesh. Bull Pure Appl Sci-Geo 2019, 38F(2), 218-24.

Mining exploration includes different geological aspects for profitable mineral extraction. By consideration of all factors for successful mining such as preparation of mineral plan, environmental management plan, waste disposal management, water management, geology, and pre cautions. Venkatampalli village is one of the richest mineral resources of the dolomite is used as a flux in the steel making, as well as in sinter making. The size of the dolomite should be +10 mm to – 30 mm for steel making and it should be 10mm for sinter making, 0.5 mm to 2 mm consumed for fertilizer industries. The maximum water table is about 150 metre from the level of ground. Thus the water table is much below the proposed working depth and the mining operations will not affected by the water regime. The expected life of the mine is around 50 years. In land environment retaining wall with waste lumps on slopes of the dump to prevent the erosion and dust generation from the dump. There is no chance for generation of toxic and hazardous element from this mine.

2 illus, 4 tables, 8 ref

006536   NIGWAL D, DEV P (Vikram Univ, Ujjain- 456 010, Email: drpdev@yahoo.com) : Hydrogeological investigation of ground water levels variation around Meghnagar Area, Jhabua Distict, Madhya Pradesh, India. Bull Pure Appl Sci-Geo 2019, 38F(2), 206-17.

The recent paper embodies results of the hydrogeological setting in the area around Meghnagar, Jhabua District of Madhya Pradesh. The usual hydrogeological survey has been carried out covering an area of 246.01 Sq. km. Well inventory involves examination of 61 dug wells existing in study area. 30 dug wells have been selected as Observation wells. Data were recorded in respect of location of well, diameter and depth of well, and measurement of static water level during post- and pre-monsoon periods to observe variations of seasonal ground water levels. The static water level during the post - monsoon period reveals a fluctuation range from 0.08 m to 4.71 m bgl, during pre - monsoon period the range of static water level varies from 3.18 to 9.10 m bgl. The fluctuations of ground water level from post- to pre- monsoon season have been observed as 2.00 to 7.42 m bgl. Based on static water level data, ground water level contour maps have been prepared. The ground water level contour maps have helped in computing direction of ground water movement. The post monsoon water level contour trend contributes in demarcations of ground water potential zones in study area. The change in direction of ground water movement can be assigned to the lithology and structural characters. The trends of ground water level fluctuation have been described as a result of excessive removal of ground water.

9 illus, 6 tables, 10 ref

006529   KATARA A, KULSHRESHTHA V, DEV P (Vikram Univ, Ujjain- 456 010, Email: drpdev@yahoo.com) : Appraisal of ground water chemical quality for drinking and domestic use in Thandla Area, Jhabua District, Madhya Pradesh, India. Bull Pure Appl Sci-Geo 2019, 38F(2), 191-205.

Paper highlights the determination of ground water chemical quality of Thandla area for drinking and domestic uses in Thandla area situated in vicinity of Jhabua district, Madhya Pradesh in India. The selected 30 ground water samples have been subjected to chemical treatment. The analyzed data have been described and interpreted for drinking and domestic applications. Based on determined values of Cations (Ca, Mg, Na, K) and Anions (Cl- , SO₄ - , CO₃ - , HCO₃ - , NO₃ - , F- ) of ground water plotted on Trilinear Piper's diagram, and compared with the World Health Organization and Indian Standard limits. In general, the ground water is suitable for drinking and domestic purpose.

3 illus, 5 tables, 38 ref

006537   NIGWAL D, DEV P (Vikram Univ, Ujjain- 456 010, Email: drpdev@yahoo.com) : Chemical quality evaluation of ground water for human application in vicinity of Meghnagar, Jhabua Region, Madhya Pradesh, India. Bull Pure Appl Sci-Geo 2019, 38F(2), 177-90.

The document presents an account of chemical quality delineation of ground water suitability for human applicators of Meghnagar study area, Jhabua district, Madhya Pradesh in India for the diverse applications. The main objective concerns to assess the ground water quality in vicinity of study area, and to delineate its suitability for domestic and, drinking applications. The representative twenty five ground water samples were collected from the open dug wells, existing in Meghnagar study area. These water samples were subjected to chemical analysis with principal objective to delineate the ground water quality for human applications Piper trilinear diagram indicates the delineation of ground water quality and reveals its suitability for The present work has been carried out with main objectives: to assess the ground water quality in vicinity of study area, and to delineate its suitability for domestic and drinking applications. It clearly shows the similarities and difference among ground water samples because those with similar qualities will tend to plot together as groups. The comparison of analyzed values with the recommended limits by Bureau of Indian Standards and World Health Organization reveal that ground water is suitable for drinking and domestic applications.

2 illus, 5 tables, 31 ref

006528   KATARA A, KULSHRESHTHA V, DEV P (Vikram Univ, Ujjain- 456 010, Email: drpdev@yahoo.com) : Open dug well data analysis of hyrdogeological system in Thandla vicinity of Jhabua Region, Madhya Pradesh, India. Bull Pure Appl Sci-Geo 2019, 38F(2), 151-63.

The paper is focused on analysis of hydrogeological system of Thandla area, located in Jhabua district of Madhya Pradesh, India. Thandla region is characterized by geological formations of Aravalli super group, Deccan Traps with Quartzite, Phyllite, Alluvium and Soil. Thandla study area is mainly covered by Deccan Traps with Quartzite and Phyllite of Aravalli Super group. Alluvium is well exposed along the course of Padmavati River. The rest of Thandla area is occupied by Deccan Traps with Limestone, Sandstone of Lameta and Bagh beds in the lava flows of Deccan traps. The well inventory of 197 open dug wells helped in the identification of 35 observation wells. The measurements of observation well data point out a diameter range from 5.55 to 11.54 m., total depth of wells vary from 5.10 to 16.00 m.b.g.l., and static water levels range from 1.70 to 14.0 m.b.g.l. The seasonal monitoring of water levels indicate a fluctuation range of 1.3 to 11.0 m.b.g.l. Ground water level contour maps of the post- and premonsoon periods indicate that in general, the ground water movement is towards the Padmavati River. In the study area, at Manpur, Khandan, Rupgarh, Prwalya, Warlipara, Jamuri, Kakarej, Miyati, Munjal, Panchpiplya, Dhamni Chhoti, Chainpuri, Machhlaimata, Kundla, Madalda, Karikurna, and Etankhera is characterized by fairly good yield of water in dug wells during even pre-monsoon period . A few number of wells become dry during pre-monsoon period at villages of Angliyapara, Bahadurpara, Kaldela, Lalgarh, Berawa, Koriyapara and Dhawrapara. In general, movement of ground water is towards the Padmavati River. Ground water potential site have been recognized in the study area.

7 illus, 5 tables, 12 ref

006521   CHAKRAVARTTY M (Geology Dep, Cotton Univ, Guwahati– 781 001, Email: madhurjyocbty@rediffmail.com) : Soil erosion susceptibility assessment for prioritization of hilly areas of a watershed in the Arunachal Himalayas in North East India based on weighted sum analysis method on morphometric parameters. Bull Pure Appl Sci-Geo 2019, 38F(2), 141-50.

In the present study, soil erosion susceptibility analysis has been carried out in the Dikrong watershed, predominantly located in the Arunachal Himalayas, applying the Weighted Sum Analysis (WSA) technique on some important morphometric parameters. Based on this approach, prioritization of the sub-watersheds has been determined by assigning weightages, derived from the correlation matrix, to the respective parameters and, accordingly, the sub-watersheds have been categorized into three priority levels viz., high, moderate, and low to very low. It has been ascertained that sub-watersheds Niorch, Chimpu, and Pang are high susceptible zones requiring urgent and efficient planning and management for better conservation.

2 illus, 6 tables, 23 ref

006540   SARMA S, TALUKDAR B P (Geology Dep, Cotton Univ, Assam– 781 001, Email: santanugw1@yahoo.com) : Effect of channel width contraction at Bogibeel bridge site on the morphology of the river Brahmaputra. Bull Pure Appl Sci-Geo 2019, 38F(2), 128-40.

The purpose of construction of bridge over the river or stream is to ensure and facilitate the smooth communication over the waterways. However, in certain engineering designs of bridge, a significant portion of waterway is occupied by the piers placed on the river bed and approach road build on the river bed. This results the constriction of the natural waterway. When the waterway is constricted because of the construction of bridges, it results detrimental effects on the morphology of the streams. The major consideration of the paper is to study the effect of constriction of the natural waterway on the river bank morphology and river island due to bridge construction. In this study, 4.94 km long Bogibeel Bridge constructed over the river Brahmaputra is taken into consideration to study the morphological changes in its upstream and downstream portion of the river reach due to the constriction of the waterway. With the completion of the construction of the piers and approach road of Bogibeel Bridge, some significant morphological changes have already been observed. The satellite imageries of the area over two decade clearly indicates the changes that took place in the river bank morphology due to the construction of the bridge structure on the river bed. Some significant gradual modification in the river bank as well as on the permanent river island is identifiable with the progress of the bridge construction. The portions of the river bank which recede alarmingly due to changes in the configuration of the river channel have been identified to take up effective and sustainable measures to reduce or stop the current erosion.

9 illus, 14 ref

006544   SURATMAN S, HEE Y Y (Malaysia Terengganu Univ, Terengganu, Malaysia, Email: yueyen_yy@hotmail.com) : Distribution of nutrients in Kelantan river basin, Malaysia. Asian J Chem 2019, 31(11), 2466-72.

This study aims to assess the influences of land use on nutrient concentrations in Kelantan river basin (southern South China Sea), in addition to the effects of monsoon seasons on nutrient concentrations. The dissolved inorganic and organic nutrients in this river were demonstrated to be related to land use during the study period. The middle and lower reaches of the river, which are surrounded by urban areas with high population densities, have enhanced levels of both dissolved inorganic and organic nutrients. Increased rainfall decreased most of the nutrient concentrations in Kelantan river basin, probably due to the dilution effect. According to The Malaysia National Water Quality Standards (NWQS) classification, the mean concentrations of dissolved inorganic phosphorus, nitrite and nitrate in Kelantan river basin fell into Class 1, which is considered at natural levels in the water column.

8 illus, 2 tables, 30 ref

006539   PRADEEPA K, LAVANYA G, INBARASAN S, SHERENE T, BALASUBRAMANIAM P (Soil Science and Agricultural Chemistry Dep, Anbil Dharmalingam Agricultural Coll and Research Institute, Tiruchirappalli- 620 009, Tamil Nadu, Email: shereneraj@yahoo.co.in) : Reclaimation of sodic bore well water for irrigation through gypsum treatment at Anbil Dharmalingam Agricultural College and Research Institute, Trichirapalli District, Tamil Nadu. Agric Sci Dig 2019, 39(4), 286-90.

It is necessary to ascertain the quality of irrigation water at Anbil Dharmalingam Agricultural College and Research Institute farm in order to monitor the possible effects of the sodic irrigation water on the soil. Irrigation with sodic water enhances soil sodicity built up in soils of experimental farm which leads to adverse effects on soil physical, chemical and biological properties, not fitted for farming. In areas where ground water is sodic and where good quality surface water supplies are either inadequate or not available at all and the farmers are left with no option but to use sodic ground water for irrigation purposes, which pose grave risks for soil health and environment. The quality of sodic water can be improved by treating with gypsum. Due to gypsum dissolution calcium and sulphate ions come in soluble form in irrigation water. Research conducted at Anbil Dharmalingam Agricultural College and Research Institute Trichy for reclamation of sodic bore well water revealed that the sodic bore water samples collected from bore well 1 (AMP shed)  having initial Residual Sodium Carbonate (RSC) of 8.0 meq /lit and bore well  6  (Boys hostel) having initial RSC of 6.2 meq /lit indicated the decrease in RSC upto - 0.6 meq / l and 1.2 meq / l respectively due to gypsum treatment with 0.1 per cent (12.50 tons/ha) and 0.35 per cent ( 43.75  tons /ha ) at the retention time of 1 hour to irrigate 1 ha paddy field throughout crop establishment stage. It was concluded that for lowest retention time higher doses of gypsum was required for sodic water reclamation. As we increased the retention time, the required gypsum quantity was also minimized as observed for bore well 1 (AMP shed 8 meq/l)) sodic water samples with gypsum dose of 0.15 per cent (18.75 tons /ha) with the retention time of 4 hours. These findings were very much helpful for the farmers of Manikandam block, Tiruchirappallii district having secondary sodicity built up in soils due to sodic water irrigation during summer.

6 ref

005225   GAO W, HUANG S, HUANG Y, YE G (Fujian Academy of Forestry, Fuzhou- 350 012) : Effects of tree species on soil carbon and nitrogen stocks in a coastal sand dune of southern subtropical China. Vegetos 2019, 32(2), 142–50.

Soil carbon (C) and nitrogen (N) cycles can be affected by different plant traits and stand properties through the influence of nutrients release to soil via mineralization. We investigated the soil C and N stocks under secondary forest and plantations of casuarina, pine, acacia and eucalyptus in a coast sand dune of Fujian province, China. Results show that the soil C and N storages, soil microbial biomass carbon (MBC), soil microbial biomass nitrogen (MBN), soil dissolved organic carbon (DOC) and nitrogen (DON) were significantly higher under secondary forest than under plantations. No significant increase was found in soil C and N storages, MBC and DOC under N-fixing trees compared with non-N-fixing trees, but the MBN and DON under acacia were all higher than non-N-fixing trees. No significant difference was found in soil C storage, MBC, MBN, DOC and DON between coniferous and broadleaf plantations. Our findings indicate that the differences in litter quality and quantity, root biomass and turnover rate are the primary cause of soil C and N stocks in coastal sand dunes, and the lack of N fixation ability may be a significant factor influencing soil C and N stocks under N-fixing trees.

44 ref

005226   HASANPORI R, SEPEHRY A, BARANI H (Gorgan Univ of Agricultural Science and Natural Resources, Golestan, Iran) : Relationship between drylands development and some soil properties. Vegetos 2019, 32(3), 303-6.

Land degradation and changing rangeland to dryland has important effects on ecosystems and soil properties. This process decline soil structure and increases runoff and erosion. Because of increasing manipulation in Iran rangelands, this research was conducted to study the effects of land use change from rangeland to dryland and abandoned dryland, on the basis of some soil factors including clay, silt and sand percent and mean weight diameter (MWD) of soil aggregates in western Iran, Zagros rangelands. Soil samples were collected in August 2016 from two depths of 0–20 and 20–50 cm in three land uses. Findings showed that this land use change affected soil properties significantly as in dryland clay, silt percent and mean weight diameter of soil aggregates were reduced and sand percent was increased. In abandoned drylands soil properties will improve gradually. Finally according to our results land use changes affected soil characteristics and this can be used in ecosystem management.

26 ref

005223   DINAKARAN J, VIKRAM K, HANIEF M, BIDALIA A, TAMBAT S, RAO K S (Botany Dep, Delhi Univ, New Delhi- 110 007) : Changes in vegetation cover and soil intrinsic properties influence the soil bacterial community composition and diversity across different climatic regions of India. Vegetos 2019, 32(3), 288-302.

Soil microbial community in forest ecosystems plays a significant role in carbon and nutrient cycling. Very little is known about the effect of vegetation cover on soil bacterial community composition and diversity across different climatic regions of India. Soil was sampled from the plant cover dominated by seasonal herbs and grasses (PAS), Pinus roxburghii Sarg (PIN), Abies pindrow L. (FIR), Quercus incana Roxb (OKF), Mitragyna parvifolia Roxb (MIK); Acacia nilotica L. and Salvadora spp. (MIA) in three different climatic regions (humid, moist sub-humid and semi-arid) of India. The soil physical, chemical and biological properties such as sand (SAN), silt (SIL), clay (CLY), bulk density (SBD), wilting point (SWP), field capacity (SFC), saturated hydraulic conductivity (SHC), pH (SpH), organic carbon (SOC), nitrogen (SN), C:N ratio, available phosphorous (SAP) and total microbial activity (SMA) were determined. Illumina sequencing of specific 16S rRNA gene was applied to identify bacterial community composition in the soils under different vegetation cover. Results showed that the soil properties varied under different vegetation cover across the different climatic regions. SOC, SN, SMA were highest in the moist sub-humid region sites (PAS, PIN) followed by humid region (OKF, FIR) and semi-arid region (MIK, MIA) sites. However, the Chao 1 (species richness), Shannon and Simpson index (diversity) were highest in OKF, followed by MIK, FIR, MIA, PIN and PAS. The predominant bacterial phyla and genera in the soils under different vegetation cover were Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Planctomycetes, Verrucomicrobia, Thermotogae and Geobacter, Methylocapsa, Sphingomonas, Pseudomonas, Erysipelotrichaceae_incertae_sedis, Sporotomaculum, Amorphus, Helicobacter, Paenibacillus, Bauldia, Skermanella, Methylosinus, Singulisphaera, Marinobacter and Lamprocystis. We also found the exclusive OTUs abundance of some bacterial phyla and genera in the soils, which were not correlated with any one of the studied soil variables. In our analysis, we found only the Firmicutes, Verrucomicrobia and Bacteroidetes are linearly correlated (P < 0.05) with CLY, SWP and SpH. Likewise, bacterial genera Methylocapsa, Methylosinus and Amorphus were linearly correlated (P < 0.05) with SIL, SpH, C:N ratio and SAP. Our results suggested that the type of vegetation cover has a significant impact on changes in soil properties, controlling the soil bacterial community composition and diversity across different climatic regions of India. The soil bacterial community composition and diversity may serve as a potential ecological indicator with respect to land use and land cover change on biogeochemical cycling processes across different climatic regions of India.

79 ref

005228   TOIGILDON ALEXANDER L, MOROZOV VLADIMIR I, PODSEVALOV-MIKHAIL I, AYUPOV DENIS E, MUSTAFINA REZIDA A, GALKIN ALEXANDER S, OSTIN VLADIMIR N (Ulyanovsk State Agricultural Univ, Russia- 432 017, Email: atoigildin@yandex.ru) : Biologization of farming and rejuvenation of soil fertility in the forest-steppe zone of the Volga region. Ambient Sci 2019, 6(2), 21-5.

The article contains the theoretical justification and the results of comprehensive studies to assess the effectiveness of biologization of crop rotations in farming in the foreststeppe zone of the Volga region. The practical implementation of biologization of farming is possible by optimally incorporating grain legumes, legume-cereal mixed crops in field crop rotations, with the use of organic-mineral fertilization systems applying manure, green manure, and straw as a source of biogenic resources of the fertility of leached black soil. On the basis of many years of research, the models of crop rotation with an optimal combination, which allows one to increase the arable land productivity and ensuring the greatest economic efficiency of its use. In the forest-steppe zone of the Volga region, well-defined grain links of crop rotations are recommended, which, unlike follow links, have higher productivity, the economic efficiency and give the possibility to accumulate additional sources of organic matter for the reproduction of fertility of leached black soil. We expanded and deepened the knowledge, that makes it possible to optimize and develop new models of mixed crops of grain legumes and perennial leguminous and cereal grasses (as a biologization factor of crop rotations) with maximum productivity and economic efficiency of cultivation. The effectiveness of the combined system of primary tillage, combining moldboard and boardless tillage ways with mini-tillin crop rotations, has been scientifically substantiated and experimentally established. The effectiveness of organic and mineral fertilizer systems with the introduction of manure, straw of grain crops and green manure in combination with optimal doses of NPK, increasing the productivity of arable land, ensuring the cost recovery in the cultivation of agricultural crops has been experimentally established.

1 illus, 1 table, 24 ref

005227   NOSKOV I, ANANEYAV S, LYUTOV V, SVIDERSKIKH A, SURTAEV A (Polzunov Altai State Technical Univ, Barnaul- 656 038, Email: gluk_cs@mail.ru) : On staging in the loess formation of Siberia. Ambient Sci 2019, 6(2), 1-6.

A generalized analysis of the staging of the loess formation in Siberia is presented, where the rocks reveal a different genesis. It has been established that the formation of loess is a geochemical process, expressed in the loessivation of fine-grained sediments and proceeding under certain physiographic conditions. The intensive development of eluvial weathering processes, soil formation, the predominance of evaporation over precipitation are associated with the same. In addition, it has been established that loess is the most dynamic and unstable system in which its constituent elements- mineral and particle size distribution, exchange bases, humidity, structure are in constant and continuous communication with the surrounding physiographic environment. The final development phase of such a system in the cycle of sedimentary rocks formation are dense calcareous loam, clay, marlite, marl. The composition and properties of loess rocks are most susceptible to changes over time and thus they are not found in sediments older than the lower Pleistocene.

5 ref

005224   FASHAHO A, NDEGWA G M, LELEI J J, MUSANDU A O, MWONGA S M (Crop Science Dep, Rwanda Univ, Musanze, Rwanda, Email: fashaho@yahoo.fr) : Variations in soil chemical properties, bacteria and fungi populations along slope positions and profile depths in terraced and non-terraced lands of Rwanda highlands. Agric Sci Dig 2019, 39(3), 215-9.

The objective of the current study was to evaluate effect of terracing on soil chemical and biological properties in the Rwanda highlands. The study was done in March 2017. Composite soil samples were collected from the top, middle and bottom slopes of four-year-terraced and non-terraced lands, in three profile depths, in medium and high altitudes. Results showed that, levels of organic carbon (1.3, 1.04%) were significantly (P < 0.05) higher in non-terraced than terraced land, and populations of bacteria (3.59, 2.61 CFU*10⁶g^-1) and fungi (2.51, 1.57 CFU*10⁴g^-1) were significantly higher in terraced than non-terraced land, in the medium altitude, with no significant differences observed in the high altitude. Soil pH, total N, available P, CEC, exchangeable K⁺, Mg²⁺ and Ca²⁺ levels in terraced and non-terraced lands were not significantly different in both altitudes. Thus, soil characteristics and fertility of the study areas showed slight changes after four years of terracing.

22 ref

004017   CHEN Y, MARINELLI F, BUSCARNERA G (Northwestern Univ, IL, USA, Email: g-buscarnera@northwestern.edu) : A rotational hardening model capturing undrained failure in anisotropic soft clays. Indian Geotech J 2019, 49(4), 369-80.

Induced anisotropy is known to play a major role in the undrained strength of clays, especially in case of weakly consolidated deposits. This paper discusses undrained failure in soft clays in light of material stability principles. For this purpose, a strain-hardening elastoplastic model widely used to study undrained instability in isotropic soils is enhanced to account for stress-induced anisotropy. A versatile yield function able to flexibly control the shape of the elastic domain is augmented through a hardening variable related to the evolving fabric, while rotational hardening is used to replicate the reorientation of the surface as a function of the loading history. Parametric analyses are used to illustrate the model capabilities, and instability indices for undrained failure are derived in analytical form. Finally, the model performance is tested against experimental evidence available for two widely tested soils: soft Chicago clay and Boston blue clay. The analyses illustrate how the proposed model allows an accurate representation of soil responses under extension and compression paths. In addition, it enables the identification of undrained failure resulting from the monotonic growth of shear stresses, as well as from a post-peak strength decay.

12 illus, 2 tables, 33 ref

004023   ESWARAN K, SATHEESH S K, SRINIVASAN J (Indian Institute of Science, Karnataka- 560 012, Email: kruthika.eswaran89@gmail.com) : Sensitivity of aerosol radiative forcing to various aerosol parameters over the Bay of Bengal. J Earth Syst Sci 2019, 128(6), 170.

In the shortwave solar spectrum (0.25−5 μm), radiation is affected by the change in various aerosol properties and also by water vapour and other gas molecules. The presence of a variety of aerosols over the Bay of Bengal (BoB) during different seasons results in a change in aerosol properties, including the aerosol layer height. The BoB is an integral part of the Indian monsoon, and hence it is essential to understand the radiation budget over the BoB. The sensitivity of the aerosol forcing due to the changes in aerosol properties and other parameters has been studied using the Santa Barbara discrete ordinates radiative transfer model. The aerosol forcing at the top of the atmosphere was found to depend on the aerosol loading (aerosol optical depth), aerosol type (single scattering albedo) and the angular distribution of the scattered radiation (asymmetry parameter). The analysis also shows the presence of a relationship between aerosol layer height and the total amount of water vapour present in the atmosphere. The present study highlights the need for better retrievals of vertical aerosol distribution and water vapour profiles for a better understanding of the role of aerosols in the climate.

7 illus, 3 tables, 121 ref

004037   KUMAR V, GOPALAKRISHNAN N, SINGH N P, CHERUKURI S (National Institute of Rock Mechanics, Bengaluru, Karnataka, Email: vikalpk@gmail.com) : Microseismic monitoring application for primary stability evaluation of the power house of the Tapovan Vishnugad hydropower project. J Earth Syst Sci 2019, 128(6), 169.

The study of micro-cracks, shear zone and redistribution of stress after excavation in the rockmass is required for a stability analysis of the underground structure. The powerhouse of the Tapovan Vishnugad Hydropower Project (TVHPP) of NTPC Ltd. is located in the seismic zone V of India and is positioned at the junction of the middle and higher Himalayan region under challenging geological conditions. The powerhouse cavern constructed by drill and blast method encountered a number of rockbursts of various intensities during and after construction. So, a real-time remote microseismic monitoring network was used to evaluate the stability of the powerhouse cavern rockmass. Strata condition, rockburst occurrence during construction and drilling feasibility for sensor installation were studied for an array of designs of the microseismic monitoring network. The primary monitoring period demarcated the micro-crack locations and probable failure zones in the powerhouse rockmass by processing and analysis of various temporal and spatial variations of microseismic parameters to evaluate the underground powerhouse structural stability. Although a large number of microseismic events occurred in the powerhouse which resulted in high displacement in a few areas, due to the low amount of energy released from the events occurring inside the powerhouse, the structure appears to be stable.

17 illus, 3 tables, 16 ref

004063   UMAR N D, IGWE O, IDRIS I G (Geology Dep, Nigeria Univ, Nsukka, Nigeria, Email: degree.umar.pg76650@unn.edu.ng) : Evaluation and characterization of groundwater of the Maastrichtian Lafia formation, Central Benue trough, Nigeria. J Earth Syst Sci 2019, 128(6), 168.

Hydrochemical assessment of groundwater in the Lafia formation, Central Benue trough, Nigeria was carried out with the aim of determining its quality for domestic and irrigation purposes. Thirty groundwater samples from boreholes and hand-dug wells were analyzed using atomic spectrometry and titrimetric methods. The water quality index (WQI) was evaluated from physicochemical parameters and used in assessing the groundwater quality for drinking, while the electrical conductivity (EC), percentage sodium (%Na), sodium absorption ratio (SAR) and magnesium hardness (MH) were evaluated to assess its suitability for irrigation. The physico-chemical parameters in order of dominance are HCO₃⁻ > NO₃⁻ > Cl⁻ > PO₃⁻ > SO₄²⁻  for the anions and Fe³⁺ > Na⁺ > Ca²⁺ > Mg²⁺ > Pb²⁺ > K⁺ for the cations. The pH indicates acidic to weakly alkaline water (5.1–7.3); EC ranges from 110 to 1396 μS/cm, while the total dissolved solids range between 136.9 and 3.4 mg/l, based on which it is classified as freshwater. WQI showed that only 40 % of the groundwater samples are suitable while 60 % are unsuitable for drinking and will therefore require treatment. Three water facies: Ca²⁺ + Mg²⁺, Ca²⁺ + Na⁺ + K⁺ and HCO₃⁻ characterized the area indicating the groundwater-quality situation. Based on EC classification, 33.33 % of the water samples are considered excellent, 60 % as good, 6.67 % as permissible while on the basis of  % Na, only 13.34 % are unsuitable for irrigation. SAR of 96.67 and 3.33 % of the groundwater samples indicate excellent and doubtful waters, respectively. 93.4 % of groundwater samples has MH < 50 and are considered suitable for irrigation.

6 illus, 5 tables, 49 ref

004033   KHODAMI M (Geology Dep, Yazd Univ, Yazd, Iran, Email: Khodami m@yazd.ac.ir) : Pb isotope geochemistry of the late Miocene–Pliocene volcanic rocks from Todeshk, the central part of the Urumieh–Dokhtar magmatic arc, Iran: Evidence of an enriched mantle source. J Earth Syst Sci 2019, 128(6), 167.

The late Miocene–Pliocene volcanic rocks from Todeshk, south-east of Isfahan, are located in the middle of the Urumieh–Dokhtar magmatic belt. The belt is considered the subduction-related magmatic arc. The late Miocene–Pliocene calc-alkaline volcanic rocks are mainly andesite and dacite. The rocks have been formed during the post-collisional stage of the Zagros orogen. Geochemical data show the enrichment of light rare-earth elements and large ion lithophile elements such as Cs, Rb, K, Pb, Ba and Th as well as the depletion of elements with high field strength such as Nb, Ta and Ti. The Pb–Sr–Nd isotopic ratios of the studied rocks are characterised by ²⁰⁶Pb/²⁰⁴Pb = 18.41–18.72; ²⁰⁷Pb/²⁰⁴Pb = 15.64– 15.67; ²⁰⁸Pb/²⁰⁴Pb = 38.49–38.83; ²⁰⁷Pb/²⁰⁶Pb = 0.8372–0.8496; ²⁰⁸Pb/²⁰⁶Pb = 2.0743–2.0905; ⁸⁷Sr/⁸⁶Sr = 0.7051–0.7068 and ¹⁴³Nd/¹⁴⁴Nd = 0.5125. The rocks have Δ7/4Pb = 15.44–15.82 and Δ8/4Pb = 57.26–60.44. Based on petrological studies and the whole rock Pb, Sr and Nd isotopes data, the late Miocene–Pliocene calc-alkaline volcanic rocks have been generated from the partial melting of the subduction-related metasomatised mantle. Additionally, the slab-derived melts and fluids were recycled into the mantle source. The data demonstrate that terrigenous sediments accompanied by a subducted slab play an important role in the formation of the enriched mantle as the source of volcanic rocks.

11 illus, 1 table, 42 ref

004025   GANGADHARAN G K, RAMTEKE C P, CHAUDHURI S N (Geological Survey of India, Kolkata- 700 091, Email: geethukg@gmail.com) : Petrographic studies to delineate suitable coal seams for coal liquefaction and their palaeo-environmental analysis: A case study from the Ib river and Mand-Raigarh coalfields of the Mahanadi valley coalfields, India. J Earth Syst Sci 2019, 128(6), 165.

A systematic approach has been carried out to delineate the coal seam zones from the Ib river coalfield, Odisha and the Mand-Raigarh coalfield, Chhattisgarh for the conversion of coal to oil as well as to establish the peat-forming environment of the mire and determine the depositional facies analysis of the coal seams. Zone R-I of Raniganj formation and Belpahar, Parkhani and Lajkura of Barakar formation from the Ib river coalfield and Seam nos. VII, VI, III and I of the Barakar formation from the MandRaigarh coalfield are identified based on their high percentage of liptinite and reactive content as well as their suitable maturity (mostly sub-bituminous rank) as potential for coal-to-oil conversion. The palaeo-depositional environment for peat formation has been constructed using the tissue preservation index and gelification index following coal facies analysis which shows that the peat formation in the Ib river coalfield took place under limnic to limno-telmatic conditions with prolonged wetness in the mire, whereas in the Mand-Raigarh coalfield, peat evolved under a clastic to an open marsh limnic environment with intermittent wet and dry spells. The microlithotype composition indicates that both the coalfields evolved under lower to upper deltaic settings.

8 illus, 2 tables, 33 ref

004067   YUAN P, CHEN R, SU Y, FAN B, WANG X (Northwest Normal Univ, Lanzhou- 730 070, Email: yuanp@nwnu.edu.cn) : Characteristic parameters of positive cloud-to-ground lightning channel. J Earth Syst Sci 2019, 128(6), 164.

The high time-resolved spectra of two natural positive cloud-to-ground (CG) lightning of which one of them contains multiple return strokes have been taken by a high-speed slit-less spectrograph. On combining with the synchronous electric field change waveform, the temperature, electrical conductivity of the return stroke channel, radius of the core current channel and the peak value of current are calculated. The correlation between the peak current and the time interval of five M components which overlapped with the continuous current following the subsequent return stroke R1 of multiple return strokes positive CG lightning were analysed. The results show that the average temperatures of the return stroke channels for two positive CG lightning are about 28,900–29,800 K, the radius of the core current channel is about 0.36–1.01 cm, the estimated peak currents of the return strokes are about 18.6–38.0 kA, which are all larger than the typical values of common negative CG lightning. The peak currents of the M components are positively correlated with the time intervals between them.

6 illus, 2 tables, 39 ref

004056   SHANKAR U, PANDEY A K (Geophysics Dep, Banaras Hindu Univ, Varanasi- 221 005, Email: umashankar@bhu.ac.in) : Estimation of gas hydrate saturation using isotropic and anisotropic modelling in the Mahanadi basin. J Earth Syst Sci 2019, 128(6), 163.

A base of gas hydrate stability zone was established after coring and drilling under the National Gas Hydrate Program (NGHP) Expedition-01 in the Mahanadi basin. At two sites, logging-while-drilling log data, and, at one site, wireline log data, were acquired during the NGHP Expedition-01. Gas hydrate reservoirs modelling can be performed in two different ways. One way is isotropic (load bearing) and, on the other hand, anisotropic media (fracture filling with gas hydrate). Here, we have performed anisotropic modelling and estimated gas hydrate saturation using P-wave velocity, assuming an incidence angle of 75^◦ represents the vertical fracture. The estimated gas hydrate saturation at sites NGHP-01-08 and NGHP01-09, assuming anisotropic media, reduces the estimate by half compared to the saturation estimation by assuming isotropic media. The saturation at site NGHP-01-19 estimated from the isotropic and anisotropic P-wave velocity models are more or less similar except in the zone (175–210 m) just above the bottom simulating reflector depth, and this zone shows similar reduction in saturation as estimated at sites NGHP-01-08 and NGHP-01-09. Observations show that average gas hydrate saturations are relatively low (up to 5 % of the pore space). The saturation of a gas hydrate estimated from an isotropic P-wave model varies from 5% to 20%. However, the saturation estimated from the anisotropic P-wave model shows a variation up to 10 % of the pore spaces at three sites.

6 illus, 1 table, 55 ref

004016   CHAKRABORTY P P, SHARMA R, KUMAR P (Geology Dep, Delhi Univ, Delhi- 110 007, Email: parthageology@gmail.com) : Earthquake-induced soft sediment deformation (SSD) structures from the Bilara limestone formation, Marwar basin, India. J Earth Syst Sci 2019, 128(6), 162.

The Neoproterozoic Bilara limestone Formation of the Marwar Group, Rajasthan, India exposes metresthick layers of soft sediment deformation (SSD) structures at different stratigraphic levels which could be traced over hundreds of metres on the outcrop scale. The SSD structures include disharmonic folds, lowangle thrusts, distorted laminae, fluidisation pipes, slump and load structures, homogeneities, diapirs, etc. Whereas SSD structures suggesting tensional stress, viz., intrastriatal graben, fluidisation, slump, etc. dominate in the lower part of the Bilara succession, features implicating compression, viz., folds, lowangle thrust are prevalent in the uppermost part. Since SSD structures are mostly confined within the algal laminites, we interpret that enhanced micritic fluid pressure below early cemented algal carbonate played a major role in laminae deformation. Depending on the degree of lithification and pore-water pressure, deformation features formed either plastically or led to diapiric injection at enhanced pore water pressure. Separated by near-horizontal underformed strata, the SSD layers, traceable over hundreds of metres, are interpreted as products of seismic shacking. Considering the time frame of the Marwar basin, i.e., the Precambrian–Cambrian transition, the SSD horizons present within the Bilara succession may hold the potential for the correlation with SSD structures reported from the time-correlative stratigraphic successions present in erstwhile adjoining tectonic terrains, e.g., China, Siberia, etc.

13 illus, 1 table, 75 ref