011533   Tenzin J;Bhaskar A S (Civil Engineering Dep , SRM Univ, Kattankulathur-603 203, Email: jigmetenzinn@gmail.com) : Modeling of the precipitation induced flash flood in Sarpang, Bhutan using HEC-RAS. Rasayan J Chem 2017, 10(2), 399-406.

Flood is define as a natural disaster that causes loss of life and property damages. Flash flood is an overflow of water that submerge lands and properties affecting lives and habitats all around the world due to climate change and heavy rainfalls. It is impossible to avoid risk or prevent their occurrence but we can reduce their effects by various engineering techniques. Incessant monsoon rains in the month of July 2016, triggered flash floods in several southern districts of Bhutan including Sarpang town affecting hundreds of people. The town was also wiped out after an overnight flash flood in 1996 and several minor flash flood kept on occurring particularly during monsoon. Hence, the present study aims to model the flash flood with respect to rainfall at Sarpang, Bhutan and to understand the suitability of methods in mountain terrain. Modelling was done by integrating ArcGIS and HEC-RAS modelling software. SRTM DEM and Landsat 8 OLI satellite image were used as base data. Meteorological data from Department of Hydro Met Services, Bhutan has been used to calculate average discharge of the river outlet. The model was validated with the recent flash flood event and also study shows that the methods and procedures adopted in this paper are suitable for carrying out similar kind of studies in mountain terrain like Sarpang where flash floods are very frequent and most common.

7 illus, 1 table, 17 ref

011532   Sinha S;Jeganathan C;Sharma L K;Nathawat M S; Das A K;Shiv Mohan (Remote Sensing Dep, Birla Institute of Technology, Mesra, Ranchi-835 215, Email: sumanrumpa.sinha@gmail.com) : Developing synergy regression models with space-borne ALOS PALSAR and landsat TM sensors for retrieving tropical forest biomass. J Earth Syst Sci 2016, 125(4), 725-35.

Forest stand biomass serves as an effective indicator for monitoring REDD (reducing emissions from deforestation and forest degradation). Optical remote sensing data have been widely used to derive forest biophysical parameters inspite of their poor sensitivity towards the forest properties. Microwave remote sensing provides a better alternative owing to its inherent ability to penetrate the forest vegetation. This study aims at developing optimal regression models for retrieving forest above-ground bole biomass (AGBB) utilising optical data from Landsat TM and microwave data from L-band of ALOS PALSAR data over Indian subcontinental tropical deciduous mixed forests located in Munger (Bihar, India). Spatial biomass models were developed. The results using Landsat TM showed poor correlation (R² = 0.295 and RMSE = 35 t/ha) when compared to HH polarized L-band SAR (R² = 0.868 and RMSE = 16.06 t/ha). However, the prediction model performed even better when both the optical and SAR were used simultaneously (R² = 0.892 and RMSE = 14.08 t/ha). The addition of TM metrics has positively contributed in improving PALSAR estimates of forest biomass. Hence, the study recommends the combined use of both optical and SAR sensors for better assessment of stand biomass with significant contribution towards operational forestry.

6 illus, 6 tables, 33 ref

011531   Singh Y;John B;Ganapathy G P;George A; Harisanth S;Divyalakshmi K S;Kesavan S (NO, VIT Univ, Vellore, Tamil Nadu, Email: b_johp@yahoo.co.in) : Geomorphic observations from southwestern terminus of Palghat gap, south India and their tectonic implications. J Earth Syst Sci 2016, 125(4), 821-39.

The region around Wadakkancheri, Trichur District, Kerala is known for microseismic activity, since 1989. Studies, subsequent to 2nd December 1994 (M =4.3) earthquake, identified a south dipping active fault (Desamangalam Fault) that may have influenced the course of Bharathapuzha River. The ongoing seismicity is concentrated on southeast of Wadakkancheri and the present study concentrated further south of Desamangalam Fault. The present study identifies the northwestern continuity of NW-SE trending Periyar lineament, which appears to have been segmented in the area. To identify the subtle landform modifications induced by ongoing tectonic adjustments, we focused on morphometric analysis. The NW-SE trending lineaments appear to be controlling the sinuosity of smaller rivers in the area, and most of the elongated drainage basins follow the same trend. The anomalies shown in conventional morphometric parameters, used for defining basins, are also closely associated with the NW-SE trending Periyar lineament/s. A number of brittle faults that appear to have been moved are consistent with the present stress regime and these are identified along the NW-SE trending lineaments. The current seismic activities also coincide with the zone of these lineaments as well as at the southeastern end of Periyar lineament. These observations suggest that the NW-SE trending Periyar lineaments/faults may be responding to the present N-S trending compressional stress regime and reflected as the subtle readjustments of the drainage configuration in the area.

8 illus, 3 tables, 44 ref

011530   Singh A;Maiti S;Tiwari R K (NO, Indian School of Mines (ISM), Dhanbad-826 004, Email: soumen_maiti2002@yahoo.co.in) : Modelling discontinuous well log signal to identify lithological boundaries via wavelet analysis: an example from KTB borehole data. J Earth Syst Sci 2016, 125(4), 761-6.

Identification of sharp and discontinuous lithological boundaries from well log signal stemming from heterogeneous subsurface structures assumes a special significance in geo-exploration studies. Well log data acquired from various geological settings generally display nonstationary/nonlinear characteristics with varying wavelengths and frequencies. Modelling of such complex well-log signals using the conventional signal processing techniques either fails to catch-up abrupt boundaries or at the best, do not provide precise information on insidious lithological discontinuities. In this paper, we have proposed a new wavelet transform-based algorithm to model the abrupt discontinuous changes from well log data by taking care of nonstationary characteristics of the signal. Prior to applying the algorithm on the geophysical well data, we analyzed the distribution of wavelet coefficients using synthetic signal generated by the first order nonstationary auto-regressive model and then applied the method on actual well log dataset obtained from the KTB bore hole, Germany. Besides identifying the formation of layered boundaries, the underlying method also maps some additional formation boundaries, which were hitherto undetected at the KTB site. The results match well with known geological lithostratigraphy and will be useful for constraining the future model of KTB bore hole data.

11 illus, 1 table, 39 ref

011529   Saha A;Kundu S;Gupta S;Vaishnav P K (Applied Mathematicws Dep, Indian Schoolm of Mines, Dhanbad-826 004, Email: sahaanup1989@gmail.com) : Effect of irregularity on torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space. J Earth Syst Sci 2016, 125(4), 885-95.

The present paper is concerned with the propagation of torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space. We assume the quadratic inhomogeneity in rigidity and density in the lower half-space and irregularity is taken in the form of rectangle at the interface separating the layer from the lower half-space. The dispersion equation for torsional waves has been obtained in a closed form. Velocity equation is also obtained in the absence of irregularity. The study reveals that the presence of irregularity, initial stress, porosity, inhomogeneity and anisotropy factor in the dispersion equation approves the significant effect of these parameters in the propagation of torsional waves in porous medium. It has also been observed that for a uniform media, the velocity equation reduces to the classical result of Love wave.

9 illus, 1 table, 34 ref

011528   Rana N;Singh S;Sundriyal Y P;Rawat G S;Juyal N (Geology Dep, HNB Garhwal Univ, Srinagar Garhwal, Email: naresh_geo@yahoo.co.in) : Interpreting the geomorphometric indices for neotectonic implications: an example of Alaknanda valley, Garhwal Himalaya, India. J Earth Syst Sci 2016, 125(4), 841-54.

Tectonic process can influence the erosion and exert the first order impression on hydrographic network of an area. Geomorphometry, a mathematical analysis of the configuration of the landforms, allows quantifying the degree of landform evolution and is widely used as a measure of tectonic deformation/uplift. Alaknanda valley lies in the tectonically active Garhwal Himalaya which has experienced two disastrous large earthquakes in the last two decades. Morphometric analyses of the valley were carried out in a fluvial erosion dominated regime and the morphometric indices were derived from the ASTER (30 m x 30 m pixel) Digital Elevation Model (DEM) using Arc GIS. The results of the analyses reveal two zones of high deformation/uplift in the valley, viz., the zone of high deformation proximal to the Main Central Thrust (MCT) in the Inner Lesser Himalaya (ILH) and the second zone of moderate deformation/uplift in the Outer Lesser Himalaya (OLH), south of the Tons Thrust (TT). The high deformation in the ILH is ascribed to the focussed convergence and high precipitation; however, the causes for the moderate deformation in the OLH are yet to be established.

10 illus, 62 ref

011527   Rai D;Pattanaik S;Rajesh P V (School of Earth Ocean and Climate Science, Indian Institute of Technology, Bhubaneswar, Odisha-751 007, Email: spt@iitbbs.ac.in) : Sensitivity of tropical cyclone characteristics to the radial distribution of sea surface temperature. J Earth Syst Sci 2016, 125(4), 691-708.

Sea Surface Temperature (SST) is crucial for the development and maintenance of a tropical cyclone (TC) particularly below the storm core region. However, storm data below the core region is the most difficult to obtain, hence it is not clear yet that how sensitive the radial distribution of the SST impact the storm characteristic features such as its inner-core structures, translational speed, track, rainfall and intensity particularly over the Bay of Bengal. To explore the effects of radial SST distribution on the TC characteristics, a series of numerical experiments were carried out by modifying the SST at different radial extents using two-way interactive, triply-nested, nonhydrostatic Advanced Weather Research and Forecast (WRF-ARW) model. It is found that not only the SST under the eyewall (core region) contribute significantly to modulate storm track, translational speed and intensity, but also those outside the eyewall region (i.e., 2-2.5 times the radius of maximum wind (RMW)) play a vital role in defining the storm's characteristics and structure. Out of all the simulated experiments, storm where the positive radial change of SST inducted within the 75 km of the storm core (i.e., P75) produced the strongest storm. In addition, N300 (negative radial changes at 300 km) produced the weakest storm. Further, it is found that SST, stronger within 2-2.5 times of the RMW for P75 experiment, plays a dominant role in maintaining 10 m wind speed (WS 10), surface entropy flux (SEF) and upward vertical velocity (w) within the eyewall with warmer air temperature (T) and equivalent potential temperature (θ_e) within the storm's eye compared to other experiments.

18 illus, 2 tables, 52 ref

011526   Parampreet Kaur;Eliyas N;Chaudhri N (Centre of Advanced Study in Geology, Panjab Univ, Chandigarh-160 014, Email: param.geol@gmail.com) : Record of post-collisional a-type magmatism in the Alwar complex, northern Aravalli orogen, NW India. Curr Sci 2017, 112(3) , 608-15.

The Alwar complex is situated in the northern part of the Aravalli orogen, NW India and contains A-type granites of late Palaeoproterozoic age. The current study focusses on the Harsora and Dadikar plutons to characterize and constrain the tectonic setting of Palaeoproterozoic felsic A-type magmatism in this crustal segment using whole-rock geochemical data. The rocks studied are metaluminous to slightly per-aluminous A-type ferroan granites. The granites are generally characterized by strongly fractionated LREE patterns with nearly flat HREE profiles and show moderate to strong negative Eu anomalies, in addition to prominent negative anomalies in Ba, Nb, Sr, P and Ti. The results show the post-collisional setting of A-type granites in the northern Aravalli orogen and signify that A-type granites may not only form in anorogenic setting. This study provides a new dimension to the understanding of palaeoproterozoic geo-dynamic evolution in the Aravalli orogen.

7 illus, 58 ref

011525   Mridula;Sinvhal A;Wason H R (Earthquake Engineering Dep, Indian Institute of Technology Roorkee, Roorkee-247 667, Email: mridulaiitr@gmail.com) : Identification of seismically susceptible areas in western Himalaya using pattern recognition. J Earth Syst Sci 2016, 125(4), 855-71.

Seismicity in the western Himalayas is highly variable. Several historical and instrumentally recorded devastating earthquakes originated in the western Himalayas which are part of the Alpine-Himalayan belt. Earthquakes cause tremendous loss of life and to the built environment. The amount of loss in terms of life and infrastructure has been rising continuously due to significant increase in population and infrastructure. This study is an attempt to identify seismically susceptible areas in western Himalaya, using pattern recognition technique. An area between latitude 29°-36°N and longitude 73°-80°E was considered for this study. Pattern recognition starts with identification, selection and extraction of features from seismotectonic data. These features are then subjected to discriminant analysis and the study area was classified into three categories, viz., Area A: most susceptible area, Area B: moderately susceptible area, and Area C: least susceptible area. Results show that almost the entire states of Himachal Pradesh and Uttarakhand and a portion of Jammu & Kashmir are classified as Area A, while most of Jammu & Kashmir is classified as Area B and the Indo-Gangetic plains are classified as Area C.

13 illus, 7 tables, 39 ref

011524   Mehak A;Mu Y;Mohsin M;Noman M;Nazir K (NO, College of Fisheries Ocean Univ of China, Qingdao-266 003, China, Email: ytmu@ouc.edu.cn) : Population dyanmics of nile Tilapia (Oreochromis niloticus) at Chashma barrage, pakistan. Indian J Geomar Sci 2017, 46(1), 206-10.

Growth and mortality parameters of Oreochromis niloticus, 480 samples collected through four research trawls during the months of April, May, June and July of 2014, were evaluated by using FiSAT-II computer package. Length-weight parameters were found to be as W = 0.001 * L ^2.144 (R² = 0.939), where W, L and R² represents weight, length and coefficient of determination. Computed von Bertalanffy growth functions, ELEFAN method, were L_∞ (asymptotic length) = 227.85 mm (FL) and K (growth coefficient) = 0.070 year^-1 respectively. Estimated value of t₀ (hypothetical length at which age is zero) remained -0.158 year^-1 whereas R_n (goodness of fit) was 0.182. Z (annual mortality rate) was evaluated as 1.11 with its 95% confidence interval at (0.74 - 1.49) and M (natural mortality) was 0.16. The value of fishing mortality (F) and exploitation ratio (E) was 0.95 year^-1 and 0.85 year^-1 correspondingly. F_max, F_0.1 and F_current were evaluated as 0.2 year^-1, 0.15 year^-1 and 0.15 year^-1 correspondingly. φ (growth performance index) was computed as 3.560. Current study suggests that the capture of this fishery resource should not exceed from current catch level.

5 illus, 35 ref

011523   Mehak A;Mu Y;Mohsin M;Noman M (NO, College of Fisheries, Ocean Univ of China, Qingdao-266 003, China, Email: ytmu@ouc.edu.cn) : Length-weight relationship of three fish species collected from Chashma barrage on the Indus river, Pakistan. Indian J Geomar Sci 2017, 46(1), 211-12.

Present study documents length-weight relationship (LWR) of three fish species, viz. Cyprinus carpio (Linnaeus, 1758), Sperata seenghala (Sykes, 1839) and Labeo rohita (F. Hamilton, 1822), sampled from Chashma Barrage on the Indus River, Pakistan. LWR of these fish species was found to be W = 0.024L^2.812, W = 0.001L^3.285 and W = 0.020L^2.902 in that order. LWR of these fish species have not been reported previously from this region.

1 table, 8 ref

011522   Manonmani R;Vidhya R;Subramani T (NO, Instititute of Remote Sensing, CEG, Anna Univ, Chennai-600 025, Email: geosubramani@annauniv.edu) : Role of multi-scale in land use/land cover change simulation model-A study in Upper Kodaganar basin, Tamil Nadu, India. Indian J Geomar Sci 2017, 46(1), 176-89.

In this paper, agent based land use model coupled with transitional probability and multiple regression model is used to simulate land use changes. The Receiver Operating Characterises (ROC) and Kappa value are used to determine the simulation accuracy between actual multiple land use and simulation of land use change map of 2011. Of the three levels, village level performed better than other two. Predicted driver was considered for future prediction for 2021, 2031 and 2041. A simulation model is used in finding out to what extent modifications occur in most dynamic land use/ land cover classes in future.

9 illus, 8 table, 35 ref

011521   Malini B H;Reddy B V;Gangaraju M;Rao K N ( Geography Dep, Andhra Univ, Visakhapatnam-530 003, Email: bhmalini@yahoo.com) : Malaria risk mapping: a study of Visakhapatnam district. Curr Sci 2017, 112(3), 463-5.

2 illus, 10 ref

011520   Li J;Sun H;Feng P (State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin Univ, Tianjin 300072, China, Email: lijanzhu@tju.edu.cn) : How to update design floods after the construction of small reservoirs and check dams: a case study from the daqinghe river basin, China. J Earth Syst Sci 2016, 125(4), 795-808 .

Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

6 illus, 7 tables, 45 ref

011519   Lee K T;Huang J K (River and Harbor Engineering Dep, National Taiwan Ocean Univ, Keelung, Taiwan 202, R.O.C., Email: aikenwoods@gmail.com) : Influence of storm magnitude and watershed size on runoff nonlinerarity. J Earth Syst Sci 2016, 125(4), 777-94.

The inherent nonlinear characteristics of the watershed runoff process related to storm magnitude and watershed size are discussed in detail in this study. The first type of nonlinearity is referred to rainfall-runoff dynamic process and the second type is with respect to a Power-law relation between peak discharge and upstream drainage area. The dynamic nonlinearity induced by storm magnitude was first demonstrated by inspecting rainfall-runoff records at three watersheds in Taiwan. Then the derivation of the watershed unit hydrograph (UH) using two linear hydrological models shows that the peak discharge and time to peak discharge that characterize the shape of UH vary event-to-event. Hence, the intention of deriving a unique and universal UH for all rainfall-runoff simulation cases is questionable. In contrast, the UHs by the other two adopted nonlinear hydrological models were responsive to rainfall intensity without relying on linear proportion principle, and are excellent in presenting dynamic nonlinearity. Based on the two-segment regression, the scaling nonlinearity between peak discharge and drainage area was investigated by analyzing the variation of Power-law exponent. The results demonstrate that the scaling nonlinearity is particularly significant for a watershed having larger area and subjecting to a small-size of storm. For three study watersheds, a large tributary that contributes relatively great drainage area or inflow is found to cause a transition break in scaling relationship and convert the scaling relationship from linearity to nonlinearity.

11 illus, 5 tables, 19 ref

011518   Kukreti B M;Sharma G K;Pramod Kumar;Hamilton S (NO, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, Email: bharatkuk@gmail.com) : Interpolation study on ambient gamma levels in parts of Khasi hills, Meghalaya (India): preliminary findings for U exploration. J Earth Syst Sci 2016, 125(4), 737-44.

This paper discusses an experimental approach to examine uranium exploration avenue over the geologically extended parts of Mahadek basin in Meghalaya, amid some of the environmental constraints. Study comprises periodic measurements of prevailing ambient gamma levels across 320 georeference points, in relation to the major litho units of Mahadek basin, covering 673 line km of Khasi Hills. Acquired sample data points were then analysed in geostatistical software (SurferTM) to develop analytical model of sample variogram having bearing on the uranium exploration in the area. Study findings have given encouraging surface indicators with mostly elevated gamma levels over the parts of West Khasi Hills. Delineated gamma anomalous zones are lithologically well correlated including to that of existing uranium occurrences in the basin. Identified anomalous zones over the parts of West Khasi Hills by this study work, are mainly associated with the Mahadek sandstone (Upper and Lower Mahadek) and Precambrian basement granites. Lower Mahadek sandstone is host rock for uranium mineralisation in the basin. Initial findings suggest with the closer spatial resolution (<126>1 km) of sample data points, the approach adopted by the study work holds promising application in locating potential uranium exploration targets especially to the extended and inaccessible parts of the basin.

6 illus, 4 tables, 23 ref

011517   Giri R K;Panda J;Rath S S;Ravindra Kumar (NO , Regional Meteorological Centre Patna, Bihar, Email: pandaj@nitrkl.ac.in ) : Validating quantitative precipitation forecast for the flood meterological office, Patna region during 2011-2014. J Earth Syst Sci 2016, 125(4), 709-23.

In order to issue an accurate warning for flood, a better or appropriate quantitative forecasting of precipitation is required. In view of this, the present study intends to validate the quantitative precipitation forecast (QPF) issued during southwest monsoon season for six river catchments (basin) under the flood meteorological office, Patna region. The forecast is analysed statistically by computing various skill scores of six different precipitation ranges during the years 2011-2014. The analysis of QPF validation indicates that the multi-model ensemble (MME) based forecasting is more reliable in the precipitation ranges of 1-10 and 11-25 mm. However, the reliability decreases for higher ranges of rainfall and also for the lowest range, i.e., below 1 mm. In order to testify synoptic analogue method based MME forecasting for QPF during an extreme weather event, a case study of tropical cyclone Phailin is performed. It is realized that in case of extreme events like cyclonic storms, the MME forecasting is qualitatively useful for issue of warning for the occurrence of floods, though it may not be reliable for the QPF. However, QPF may be improved using satellite and radar products.

14 illus, 3 tables, 30 ref

011516   Cai Z;Yi H;Xia G;You H (NO, Institute of Sedimentary Geology, Univ of Technology, Chengdu-610 059, China, Email: zhanhucai@gmail.com) : Carboniferous-permian carbon isotope stratigraphy of succession from Xianza (Tibet), China. Indian J Geomar Sci 2017, 46(1) , 55-64.

Carbon isotopic composition recorded several major events in the development and evaluation of the earth. Possibly, Carbon isotopic composition is the cause or the result of such big events. Carboniferous-Permian, as the most important turning point of earth development history, developed the biggest Phanerozoic glacier whose drift beds are widely distributed among the various ancient Gondwanaland continental blocks. We can carry out comparative study with each continental block. Good outcrop of Chinese carboniferous sequence and continuously developed stratum are fit for building chronostratigraphic framework and proceeding global comparative studies. The paper researches on carbon and oxygen isotope of the samples from Carboniferous-Permianstratigraphic boundary which are collected from the east Yongzhu bridge of Xainza County in Tibet Autonomous Region, China. Moreover, we compare it with carbon isotope curve of the same period coming from the Kongshan section in Jiangsu Province, the Zhongdi sectionand Naqing section in Guizhou Province of the south China. It is the first time to propose the concrete beds location of Carboniferous-Permian stratigraphic boundary of Xainzadistrict which is one set of yellow limestone below the LagaFormaion.In previous studies, index fossils were not found in LagaFm. It was roughly defined as a diachronous lithostratigraphic unit simply by 26 genera of brachiopods and 8 genera of rugose corals. In this paper, based on a comparative study with carbon isotope curves, the Laga Fm. is identified as a time-transgressive formation.

5 illus, 52 ref

011515   Balasaraswathi P;Srinivasalu S (NO, Institute for Ocean Management, Anna Univ, Chennai-600 025, Email: balasaraswathi19@gmail.com) : Spatio-temporal analysis of muthupet lagoon using geomatics techniques. Indian J Geomar Sci 2017, 46(1), 74-7.

Present study consists the spatio-temporal analysis of the stored information, using a Toposheet of 1970 as a reference surface. A drastic increase of the surface area of the lagoon has been observed between the years 1970 and 1991 (from 12.82 to 18.49km2 of the lagoon reference surface. While there was no sand bar found in lagoon (1970), the presence of mud flats were identified in the year 1991 and started increasing, reached its maximum areal extent (0.56km2) in 2015. Analysis result deterioration in the width of the lagoon mouth from 1.03km, 1991 to 0.80km, 2015.

3 illus, 1 table, 8 ref

011514   Balasaraswathi P;Srinivasalu S (NO, Institute for Ocean Management, Anna Univ, Chennai-25, Email: balasaraswathi19@gmail.com) : Shoreline dynamics of Nagapattinam coast by natural intervening geomorphic system and artificial structures. Indian J Geomar Sci 2017, 46(1), 65-73.

Shoreline changes are identified and analyzed using Geomatics techniques coupled with Digital shoreline analysis system (DSAS) for knowing the impacts on Nagapattinam coast. Shoreline change rates (m/yr) are estimated with respect to End point rate (EPR) and Linear regression rate (LRR) that depict considerable changes on the north and south side of intervening rivers and artificial structures on the adjacent shorelines (between 1991 and 2014). Present study explains the erosion observed at northern side of the Uppanaru river, Vettaru river and Seruthur river. Both erosion and accretion noticed on the northern side of the Vettaikaraniruppu river is discussed. This also indicates the drastic accretion noticed on northern side of the Karaikkal port and Nagapattinam port and examined the erosion at the southern side of both ports.

6 illus, 1 table, 31 ref

011513   Arulmozhi S;Prince Arulraj G (Civil Engineering Dep, Excel College of Technology, Coimbatore-637 303, Email: arul3345@gmail.com) : Rainfall variation and frequency analysis study of Salem district Tamil Nadu. Indian J Geomar Sci 2017, 46(1), 213-18.

Average rainfall and rainy days in Salem district during 32 years were calculated as 945.7mm and 52 days. Highest monthly rainfall 167.9mm occurred in September mostly during the south west monsoon and the highest rainy days were observed in October (8.44 days). Rainfall occurred in southwest monsoon, north east monsoon, winter and summer were 450.4, 324.2, 6.5, and 164.6 respectively. Rainfall frequency analysis revealed that the average annual rainfall of 890.80 mm can be expected to occur once in 2.5 years with a probability of 40%. Monthly dependable rainfall is expected to occur every year from August to October. Based on the results the soil and water conservation structures, crop planning and management can be designed.

4 illus, 3 table, 10 ref

011512   Arulmozhi S;Prince Arulraj G (Civil Engineering Dep, Excel College of Technology, Coimbatore-637 303, Email: arul3345@gmail.com) : Evaluation of the groundwater quality feasibility zones for irrigation purpose in Salem district, Tamil Nadu India. Indian J Geomar Sci 2017, 46(1), 196-202.

Groundwater samples from 26 bore wells were collected at various locations in Salem District during pre monsoon period (June to July 2013) and post monsoon period (December 2013 - January 2014) were analyzed for their physicochemical characteristics. Each parameter was compared with the standard permissible limits of the parameter as prescribed by the World Health Organization (WHO).

9 illus, 3 table, 12 ref

011511   Agarwal A;Agarwal K K;Bali R;Prakash C;Joshi G (Laboratorio de Paleomagnetismo, Instituto de Geofisica, UNAM, Mexico City, Mexico, Email: amar@daad-alumni.de) : Back-thrusting in lesser himalaya: evidences from magnetic fabric studies in parts of Almora crystalline zone, Kumaun lesser Himalaya. J Earth Syst Sci 2016, 125(4), 873-84.

The present study aims to understand evolution of the Lesser Himalaya, which consists of (meta) sedimentary and crystalline rocks. Field studies, microscopic and rock magnetic investigations have been carried out on the rocks near the South Almora Thrust (SAT) and the North Almora Thrust (NAT), which separates the Almora Crystalline Zone (ACZ) from the Lesser Himalayan sequences (LHS). The results show that along the South Almora Thrust, the deformation is persistent; however, near the NAT deformation pattern is complex and implies overprinting of original shear sense by a younger deformational event. We attribute this overprinting to late stage back-thrusting along NAT, active after the emplacement of ACZ. During this late stage back-thrusting, rocks of the ACZ and LHS were coupled. Back-thrusts originated below the Lesser Himalayan rocks, probably from the Main Boundary Thrust, and propagated across the sedimentary and crystalline rocks. This study provides new results from multiple investigations, and enhances our understanding of the evolution of the ACZ.

9 illus, 47 ref

011510   Abong A A;George A M;Awhuwhe E A (Physics Dep, Cross River Univ of Technology, P.M.B. 1123 Calabar-Nigeria) : Investigation of time scale dependence of gutenberg-richter's frequency-magnitude relationship in South Africa. Int J appl Sci Engng Res 2010, 5(2), 129-36.

Time scale dependence of Gutenberg Richter's relationship was investigated. The work set out to see how time interval within which an earthquake epicentre is selected affects the values of the constants a and b in the Gutenberg Richter's relationship. The region of study was varied between 1963-1972, 1973-1982, 1983-1992, 1993-2002 and 2003-2012. The results of the study showed that the values of a and b change as the time interval changes. This means that seismicity does not vary uniformly in temporal dimensions. b varies from 0.67 to 1.11 and a from 4.61 to 6.76 in the study area. These high b-values observed are an indication that the study area is weak and heterogeneous and has experienced low stress concentration and large number of aftershocks in the last fifty years.

7 illus, 1 table, 26 ref

010503   Zhang Y F;Wang X P;Pan Y X;Hu R (Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China, Email: zuf7759961@163.com) : Comparison of diurnal dynamics in evaporation rate between bare soil and moss-crusted soil within a revegetated desert ecosystem of northwestern China. J Earth Syst Sci 2016, 125(1), 95-102.

Effects of biological soil crusts (BSCs) on soil evaporation is quite controversial in literature, being either facilitative or inhibitive, and therein few studies have actually conducted direct evaporation measurements. Continuous field - 50 - measurements of soil water evaporation were conducted on two microlysimeters, i.e., one with sand soil collected from bare sand dune area and the other with moss-crusted soil collected from an area that was revegetated in 1956, from field capacity to dry, at the southeastern edge of the Tengger Desert. We mainly aimed to quantify the diurnal variations of evaporation rate from two soils, and further comparatively discuss the effects of BSCs on soil evaporation after revegetation. Results showed that in clear days with high soil water content (Day 1 and 2), the diurnal variation of soil evaporation rate followed the typical convex upward parabolic curve, reaching its peak around mid-day. Diurnal evaporation rate and the accumulated evaporation amount of moss-crusted soil were lower (an average of 0.90 times) than that of sand soil in this stage. However, as soil water content decreased to a moderately low level (Day 3 and 4), the diurnal evaporation rate from moss-crusted soil was pronouncedly higher (an average of 3.91 times) than that of sand soil, prolonging the duration of this higher evaporation rate stage; it was slightly higher in the final stage (Day 5 and 6) when soil moisture was very low. We conclude that the effects of moss crusts on soil evaporation vary with different evaporation stages, which is closely related to soil water content, and the variation and transition of evaporation rate between bare soil and moss-crusted soil are expected to be predicted by soil water content.

6 illus, 33 ref

010502   Yin J;Yan D;Yang Z;Yuan Z;Yuan Y;Zhang C (State Key Laboratory of Simulation and Refulation of Water Cycle in R, Water Resources Research Dep, China Institute of Water Resources and H, Beijing 100038, China, Email: yandh@iwhr.com) : Projection of extreme precipitation in the context of climate change in Huang-Huai-Hai region, China. J Earth Syst Sci 2016, 125(2), 417-29.

Based on the national precipitation dataset (0.5° x 0.5°) 1961-2011, published by the National Meteorological Information Center of China and the five Global Climate Models provided by ISI-MIP, annual maximum precipitation for 1 day, 3 days and 7 days could be calculated. Extreme precipitation was fitted via Generalized Extreme Value (GEV) distribution to explore the changes of extreme precipitation with the return period of 20 years and 50 years during 1961-2000 and 2001-2050. Based on this, extreme precipitation projection in Huang-Huai-Hai region was done. The results showed that the five Global Climate Models could simulate the statistical features of extreme precipitation quite well, in which IPSL-CM5A-LR has the highest precision. Simulation of IPSL-CM5A-LR indicates that precipitation with the return period of 20 years and 50 years in the middle reaches of the Yellow River, middle and lower reaches of Huaihe River and plain area of the southern Haihe River will increase considerably in the future. Extreme precipitation in some of the places will even increase by more than 30%, which means that these places will face larger flood risk and their capacity to respond to flood disasters should be improved.

9 illus, 8 tables, 33 ref

010501   Xiao Y;Zhou G;Yang F S (National Inland Waterway Refulation Engineering Research Center, Chongging Jiaotong Univ, Chongging, China, Email: rymttlove@163.com) : 2D numerical modelling - 49 - of meandering channel formation. J Earth Syst Sci 2016, 125(2), 251-67.

A 2D depth-averaged model for hydrodynamic sediment transport and river morphological adjustment was established. The sediment transport submodel takes into account the influence of non-uniform sediment with bed surface armoring and considers the impact of secondary flow in the direction of bed-load transport and transverse slope of the river bed. The bank erosion submodel incorporates a simple simulation method for updating bank geometry during either degradational or aggradational bed evolution. Comparison of the results obtained by the extended model with experimental and field data, and numerical predictions validate that the proposed model can simulate grain sorting in river bends and duplicate the characteristics of meandering river and its development. The results illustrate that by using its control factors, the improved numerical model can be applied to simulate channel evolution under different scenarios and improve understanding of patterning processes.

22 illus, 4 tables, 43 ref

010500   Twinkle D;Srinivasa Rao G S;Radhakrishna M; Murthy K S R (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: mradhakrishna@iitb.ac.in) : Crustal structure and rift tectonics across the Cauvery-Palar basin, Eastern continental margin of India based on sismic and potential field modelling. J Earth Syst Sci 2016, 125(2), 329-42.

The Cauvery-Palar basin is a major peri-cratonic rift basin located along the Eastern Continental Margin of India (ECMI) that had formed during the rift-drift events associated with the breakup of eastern Gondwanaland (mainly India-Sri Lanka-East Antarctica). In the present study, we carry out an integrated analysis of the potential field data across the basin to understand the crustal structure and the associated rift tectonics. The composite-magnetic anomaly map of the basin clearly shows the onshore-to-offshore structural continuity, and presence of several high-low trends related to either intrusive rocks or the faults. The Curie depth estimated from the spectral analysis of offshore magnetic anomaly data gave rise to 23 km in the offshore Cauvery-Palar basin. The 2D gravity and magnetic crustal models indicate several crustal blocks separated by major structures or faults, and the rift-related volcanic intrusive rocks that characterize the basin. The crustal models further reveal that the crust below southeast Indian shield margin is ~36 km thick and thins down to as much as 13-16 km in the Ocean Continent Transition (OCT) region and increases to around 19-21 km towards deep oceanic areas of the basin. The faulted Moho geometry with maximum stretching in the Cauvery basin indicates shearing or low angle rifting at the time of breakup between India-Sri Lanka and the East Antarctica. However, the additional stretching observed in the Cauvery basin region could be ascribed to the subsequent rifting of Sri Lanka from India. The abnormal thinning of crust at the OCT is interpreted as the probable zone of emplaced Proto-Oceanic Crust (POC) rocks during the breakup. The derived crustal structure along with other geophysical data further reiterates sheared nature of the southern part of the ECMI.

7 illus, 61 ref

010499   Srivastava A K;Voogt J;Kshirsagar S R; Srivastava K (India Meterological Dep, , Shivajinagar, Pune-411 005, Email: aksrivastava@hotmail.com) : Heat islands over Mumbai as revealed by autorecorded thermograph data. J Earth Syst Sci 2016, 125(1), 85-93.

This study examined hourly temperature data of two locations of Mumbai metropolitan city. One data point (Coloba, Mumbai) is in centre of the city and the other one (Santacruz, Mumbai) is at the airport. The study finds that there were many occasions when night-time hourly temperatures over the city centre were considerably higher than that of the airport, even though temperature at the time of sunset at both the places was nearly same. In this study, the occasions, when hourly night-time temperature over city was more than that of the airport by objectively defined threshold value (3.0 øC in this study) for most of the hours in the night, were termed as heat island events. Analysis of the study reveals that these events are mostly confined to November-February months. The study also found that frequency of such events has doubled in recent two decades in comparison to the earlier two decades.

7 illus, 6 ref

010498   Silva J D;Sonnadara D U J (Physics Dep, Colombo Univ, Colombo, Sri Lanka, Email: upul@phys.cmb.ac.lk) : Century scale climate change in the central highlands of Sri Lanka. J Earth Syst Sci 2016, 125(1), 75-84.

In this study, an analysis of century scale climate trends in the central highlands of Sri Lanka is presented. Monthly rainfall and temperature records of the period 1869-2006 from five climatological stations were analyzed. The trend is calculated by the least square regression analysis and the significance of the observed trend is estimated using the Mann-Kendall statistic. The results clearly show that there is a statistically significant decrease in annual rainfall in the western slopes of the central highlands. Throughout the last century, the annual reduction of rainfall in Nuwara Eliya which is at an altitude of 1895 m was 5.2 mm/year. The decrease is largely due to the reduction in southwest monsoon rainfall which contributes to 75% of the total reduction. No significant change was observed on the eastern side of the central highlands which receives rainfall predominantly from the northeast monsoons. The mean annual temperature in the mountainous region shows a uniform increasing trend which is in line with the 100-year global temperature increase of 0.8 ñ 0.2øC. Kandy, which is at an altitude of 477 m and closely linked with the rainfall climatology of Nuwara Eliya, showed no significant change in the mean annual temperature. If the current trend continues, in another 100 years, western and eastern slopes of central highlands will receive the same amount of rainfall from the southwest monsoon and the northeast monsoon which will have far reaching consequences for Sri Lanka's economy and the ecology of the hill country.

7 illus, 3 tables, 19 ref

010497   Sandjo A F Y;Njanko T;Njonfang E;Errami E; Rochette P;Fozing E (Laboratory of Environmental Geology, Dschang Univ, P.O. Box 67, Daschang, Cameroon, Email: angeyakeu1@gmail.com) : Transpressional granite-emplacement model: structural and manetic study of the Pan-African Bandja granitic pluton (West Cameroon). J Earth Syst Sci 2016, 125(1), 179-202.

The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ñ17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

14 illus, 2 tables, 63 ref

010496   Sahu P;Sikdar P K;Chakraborty S (School of Environment and Sustainable Development, Central Univ of Gujarat, Gandhinagar-382 030, Email: paulami_sahu@cug.ac.in) : Geochemical evolution of groundwater in southern Bengal basin: the example of Rajarhat and adjoining areas, West Bengal, India. J Earth Syst Sci 2016, 125(1), 129-45.

Detailed geochemical analysis of groundwater beneath 1223 km2 area in southern Bengal Basin along with statistical analysis on the chemical data was attempted, to develop a better understanding of the geochemical processes that control the groundwater evolution in the deltaic aquifer of the region. Groundwater is categorized into three types: `excellent', `good' and `poor' and seven hydrochemical facies are assigned to three broad types: `fresh', `mixed' and `brackish' waters. The `fresh' water type dominated with sodium indicates active flushing of the aquifer, whereas chloride-rich `brackish' groundwater represents freshening of modified connate water. The `mixed' type groundwater has possibly evolved due to hydraulic mixing of `fresh' and `brackish' waters. Enrichment of major ions in groundwater is due to weathering of feldspathic and ferro-magnesian minerals by percolating water. The groundwater of Rajarhat New Town (RNT) and adjacent areas in the north and southeast is contaminated with arsenic. Current-pumping may induce more arsenic to flow into the aquifers of RNT and Kolkata cities. Future large-scale pumping of groundwater beneath RNT can modify the hydrological system, which may transport arsenic and low quality water from adjacent aquifers to presently unpolluted aquifer.

8 illus, 6 tables, 76 ref

010495   Reddy C S;Jha C S;Dadhwal V K (National Remote Sensing Centre, Indian Space Research Organisation, Balanagar, Hyderabad-500 037, Email: drsudhakarreddy@gmail.com) : Assessment and monitoring of long-term forest cover changes (1920-2013) in - 46 - Western ghats biodiversity hotspot. J Earth Syst Sci 2016, 125(1), 103-14.

Western Ghats are considered as one of the global biodiversity hotspots. There is an information gap on conservation status of the biodiversity hotspots. This study has quantified estimates of deforestation in the Western Ghats over a period of past nine decades. The classified forest cover maps for 1920, 1975, 1985, 1995, 2005 and 2013 indicates 95,446 (73.1%), 63,123 (48.4%), 62,286 (47.7%), 61,551 (47.2%), 61,511 (47.1%) and 61,511 km² (47.1%) of the forest area, respectively. The rates of deforestation have been analyzed in different time phases, i.e., 1920-1975, 1975-1985, 1985-1995, 1995-2005 and 2005-2013. The grid cells of 1 km² have been generated for time series analysis and describing spatial changes in forests. The net rate of deforestation was found to be 0.75 during 1920-1975, 0.13 during 1975-1985, 0.12 during 1985-1995 and 0.01 during 1995-2005. Overall forest loss in Western Ghats was estimated as 33,579 km² (35.3% of the total forest) from 1920's to 2013. Land use change analysis indicates highest transformation of forest to plantations, followed by agriculture and degradation to scrub. The dominant forest type is tropical semi-evergreen which comprises 21,678 km² (35.2%) of the total forest area of Western Ghats, followed by wet evergreen forest (30.6%), moist deciduous forest (24.8%) and dry deciduous forest (8.1%) in 2013. Even though it has the highest population density among the hotspots, there is no quantifiable net rate of deforestation from 2005 to 2013 which indicates increased measures of conservation.

5 illus, 17 tables, 38 ref

010494   Rao P B V S;Radhakrishna M;Haripriya K;Rao B S;Chandrasekharam D (NO, Indian Institute of Geomagnetism, Kalamboli Highway, Panvel, Navi Mumbai-410 218, Email: mradhakrishna@iitb.ac.in) : Magnetic anomalies over the Andaman Islands and their geological significance. J Earth Syst Sci 2016, 125(2), 359-68.

The Andaman Islands form part of the outer-arc accretionary sedimentary complex belonging to the Andaman-Sumatra active subduction zone. The islands are characterized by thick cover of Neogene sediments along with exposed ophiolite rocks at few places. A regional magnetic survey was carried out for the first time over the Andaman Islands with a view to understand the correlation of anomaly signatures with surface geology of the islands. The residual total field magnetic anomaly maps have revealed distinct magnetic anomalies having intermediate to high amplitude magnetic signatures and correlate with the areas over/close to the exposed ophiolite rocks along the east coast of north, middle and the south Andaman Islands. The 2D modelling of magnetic anomalies along selected E-W profiles across the islands indicate that the ophiolite bodies extend to a depth of about 5-8 km and spatially correlate with the mapped fault/thrust zones.

5 illus, 1 table, 41 ref

010493   Puah Y J;Huang Y F;Chua K C;Lee T S (Civil Eng9ineering Dep, Univ Tunku Abdul Rahman, Jalan Genting Klang, Setapak, 53300 Kuala Lumpur, Malaysia, Email: pyanjun421@gmail.com) : River catchment rainfall series analysis using additive Holt-winters method. J Earth Syst Sci 2016, 125(2), 269-83.

Climate change is receiving more attention from researchers as the frequency of occurrence of severe natural disasters is getting higher. Tropical countries like Malaysia have no distinct four seasons; rainfall has become the popular parameter to assess climate change. Conventional ways that determine rainfall trends can only provide a general result in single direction for the whole study period. In this study, rainfall series were modelled using additive Holt-Winters method to examine the rainfall pattern in Langat River Basin, Malaysia. Nine homogeneous series of more than 25 years data and less than 10% missing data were selected. Goodness of fit of the forecasted models was measured. It was found that seasonal rainfall model forecasts are generally better than the monthly rainfall model forecasts. Three stations in the western region exhibited increasing trend. Rainfall in southern region showed fluctuation. Increasing trends were discovered at stations in the south-eastern region except the seasonal analysis at station 45253. Decreasing trend was found at station 2818110 in the east, while increasing trend was shown at station 44320 that represents the north-eastern region. The accuracies of both rainfall model forecasts were tested using the recorded data of years 2010-2012. Most of the forecasts are acceptable.

5 illus, 6 tables, 25 ref

010492   Pattanaik D R;Mohapatra M (India Meterological Dep, , New Delhi-110 003, Email: drpattanaik@gmail.com) : Seasonal forecasting of tropical cyclogenesis over the North Indian ocean. J Earth Syst Sci 2016, 125(2), 231-50.

Over the North Indian Ocean (NIO) and particularly over the Bay of Bengal (BoB), the post-monsoon season from October to December (OND) are known to produce tropical cyclones, which cause damage to life and property over India and many neighbouring countries. The variability of frequency of cyclonic disturbances (CDs) during OND season is found to be associated with variability of previous large-scale features during monsoon season from June to September, which is used to develop seasonal forecast model of CDs frequency over the BoB and NIO based on principal component regression (PCR). Six dynamical/thermodynamical parameters during previous June-August, viz., (i) sea surface temperature (SST) over the equatorial central Pacific, (ii) sea level pressure (SLP) over the southeastern equatorial Indian Ocean, (iii) meridional wind over the eastern equatorial Indian Ocean at 850 hPa, (iv) strength of upper level easterly, (v) strength of monsoon westerly over North Indian Ocean at 850 hPa, and (vi) SST over the northwest Pacific having significant and stable relationship with CDs over BoB in subsequent OND season are used in PCR model for a training period of 40 years (1971-2010) and the latest four years (2011-2014) are used for validation. The PCR model indicates highly significant correlation coefficient of 0.77 (0.76) between forecast and observed frequency of CD over the BoB (NIO) for the whole period of 44 years and is associated with the root mean square error and mean absolute error = 1 CD. With respect to the category forecast of CD frequency over BoB and NIO, the Hit score is found to be about 63% and the Relative Operating Curves (ROC) for above and below normal forecast is found to be having much better forecast skill than the climatology. The PCR model performs very well, particularly for the - 45 - above and below normal CD year over the BoB and the NIO, during the test period from 2011 to 2014.

14 illus, 6 tables, 49 ref

010491   Pandey D K;Rai S;Sahai A K;Abhilash A;Shahi N K (K. Banerjee Centre of Atmospheric and Ocean Studies, Allahabad Univ, Allahabad-211 002, Email: raishail77@gmail.com) : Prediction and error growth in the daily forecast of precipitation from the NCEP CFSv2 over the subdivisions of Indian subcontinent. J Earth Syst Sci 2016, 125(1), .

This study investigates the forecast skill and predictability of various indices of south Asian monsoon as well as the subdivisions of the Indian subcontinent during JJAS season for the time domain of 2001-2013 using NCEP CFSv2 output. It has been observed that the daily mean climatology of precipitation over the land points of India is underestimated in the model forecast as compared to observation. The monthly model bias of precipitation shows the dry bias over the land points of India and also over the Bay of Bengal, whereas the Himalayan and Arabian Sea regions show the wet bias. We have divided the Indian landmass into five subdivisions namely central India, southern India, Western Ghat, northeast and southern Bay of Bengal regions based on the spatial variation of observed mean precipitation in JJAS season. The underestimation over the land points of India during mature phase was originated from the central India, southern Bay of Bengal, southern India and Western Ghat regions. The error growth in June forecast is slower as compared to July forecast in all the regions. The predictability error also grows slowly in June forecast as compared to July forecast in most of the regions. The doubling time of predictability error was estimated to be in the range of 3-5 days for all the regions. Southern India and Western Ghats are more predictable in the July forecast as compared to June forecast, whereas IMR, northeast, central India and southern Bay of Bengal regions have the opposite nature.

11 illus, 1 table, 55 ref

010490   Pal S K;Vaish J;Sahadev Kumar;Bharti A K (Applied Geophysics Dep, Indian School of Mines, Dhanbad-826 004, Email: sanjitism@gmail.com) : Coal fire mapping of east Basuria colliery, Jharia coalfield using vertical derivative technique of magnetic data. J Earth Syst Sci 2016, 125(1), 165-78.

The present study deals with the coal fire mapping of East Basuria Colliery, Jharia coalfield, India, using the magnetic method. It is based on the fact that rise in temperature would result significant changes in magnetic susceptibility and thermo-remanent magnetization (TRM) of the overlying rocks. Magnetism increases slowly with the rise of temperature until the Curie temperature. Generally, rock/ overburden loses magnetization and becomes paramagnetic due to heating to Curie temperature, which results with significant reduction in magnetic susceptibility. However, magnetism increases significantly after cooling below the Curie temperature. Several data processing methods such as diurnal correction, reduction to pole (RTP), first and second vertical derivatives have been used for analysis of magnetic data and their interpretation. It is observed that the total magnetic field intensity anomaly of the area varies approximately from 44850 to 47460 nT and the residual magnetic anomaly varies approximately from -1323 to 1253 nT. The range of the magnetic anomaly after RTP is approximately 1050-1450 nT. About 20 low magnetic anomaly zones have been identified associated with active coal fire regions and 11 high magnetic anomaly zones have been identified associated with non-coal fire regions using vertical derivative techniques.

5 illus, 2 tables, 82 ref

010489   Ozcelik M (Geological Engineering Dep, Suleyman Demirel Univ, 32260 Isparta, Turkey, Email: ozcelikmehmet@sdu.edu.tr) : Evaluation of soft sediment deformation - 43 - structures along the Fethiye-Burdur Fault Zone, SW Turkey. J Earth Syst Sci 2016, 125(2), 343-58.

Burdur city is located on lacustrine sedimentary deposits at the northeastern end of the Fethiye-Burdur Fault Zone (FBFZ) in SW Turkey. Fault steps were formed in response to vertical displacement along normal fault zones in these deposits. Soft sediment deformation structures were identified at five sites in lacustrine sediments located on both sides of the FBFZ. The deformed sediments are composed of unconsolidated alternations of sands, silts and clay layers and show different morphological types. The soft sediment deformation structures include load structures, flame structures, slumps, dykes, neptunian dykes, drops and pseudonodules, intercalated layers, ball and pillow structures, minor faults and water escape structures of varying geometry and dimension. These structures are a direct response to fluid escape during liquefaction and fluidization mechanism. The driving forces inferred include gravitational instabilities and hydraulic processes. Geological, tectonic, mineralogical investigations and age analysis were carried out to identify the cause for these soft sediment deformations. OSL dating indicated an age ranging from 15161ñ744 to 17434ñ896 years for the soft sediment deformation structures. Geological investigations of the soft sediment deformation structures and tectonic history of the basin indicate that the main factor for deformation is past seismic activity.

14 illus, 2 tables, 97 ref

010488   Oikonomidis D;Albanakisl K;Pavlides S;Fytikas M (Aristotle Univ of Thessaloniki, School of Geology, 54124, Thessaloniki, Greece, Email: oikonomi@geo.auth.gr) : Reconstruction of the paleo-coastline of Santorini island (Greece), after the 1613 BC volcanic eruption: a GIS-based quantitative methodology. J Earth Syst Sci 2016, 125(1), 1-11.

A catastrophic volcanic explosion took place in Thera/Santorini island around 1613 BC, known as the `Minoan' eruption. Many papers have dealt with the shape of the shoreline of the island before the eruption, but none with the shape of the shoreline exactly after it, assuming that it would be the same with the contemporary one. However, this is not correct due to the wave erosion. In this paper, a new DEM was constructed, covering both land and submarine morphology, then topographic sections were drawn around the island. Using these sections, the `missing parts' (sea-wave erosion) were calculated, the shoreline was reconstructed as it was one day after the eruption and finally the erosion rate was calculated.

10 illus, 1 table, 35 ref

010487   Oha I A;Onuoha K M;Nwegbu A N;Abba A U (Geology Dep, Nigeria Univ, Nsukka, Nigeria, Email: ifeanyi.oha.edu.ng) : Interpretation of high resolution aeromagnetic data over southern Benue trough, southeastern Nigeria. J Earth Syst Sci 2016, 125(2), 369-85.

High resolution airborne magnetic data of parts of the southern Benue Trough were digitally processed and analyzed in order to estimate the depth of magnetic sources and to map the distribution and orientation of subsurface structural features. Enhancement techniques applied include, reduction to pole/equator (RTP/RTE), first and second vertical derivatives, horizontal gradients and analytic signal. Results from these procedures show that at least 40% of the sedimentary basin contain shallow (<200 m) magmatic bodies, which in most cases are intermediate to mafic intrusive and hyperbysal rocks, and may occur as sills, dikes or batholiths. Magnetic lineaments with a predominant NE-SW trend appear to be more densely distributed around the basement rocks of the Oban Hills and metamorphosed rocks around the Workum Hills. 3D standard Euler deconvolution and Source Parameter Imaging (SPI TM) techniques were employed for depth estimation. Results from the two methods show similar depth estimates. The maximum depth to basement values for 3D Euler and SPI are 4.40 and 4.85 km with mean depths of 0.42 and 0.37 km, respectively. Results of 2D modelling of magnetic profiles drawn perpendicular to major anomalies in the study area reveal the existence of deep seated faults which may have controlled the emplacement of intrusive bodies in the basin. The abundance of intrusive bodies in the study area renders this part of the southern Nigerian sedimentary basins unattractive for petroleum exploration. However, the area possesses high potential for large accumulation of base metal mineralization.

11 illus, 2 tables, 50 ref

010486   Niu H;He Y;Kang S;Lu X;Shi X;Wang S (State Key Laboratory of Cryospheric Science, Cold and Arid Regions Env, Chinese Academy of Sciences, Lanzhou 730000, China, Email: shichang.kang@itpcas.ac.cn) : Chemical compositions of snow from Mt. Yulong, southeastern Tibetan plateau. J Earth Syst Sci 2016, 125(2), 403-16.

The snow and ice in Mt. Yulong offer a unique opportunity to investigate changes in climate and large scale atmospheric circulations over Asia. During February and April 2012, surface snow samples were collected from the Baishui Glacier No. 1 at different altitudes along the eastern slope of Mt. Yulong. Two snowpits were also excavated from Mt. Yulong at altitudes of 4780 and 4730 m a.s.l. in February 2012. The concentrations of inorganic ions were higher at an elevation of 4506 m a.s.l. in the glacier with significant contribution of anthropogenic (mainly NH⁺₄, SO^2-₄, NO^-₃) and crustal (mainly Ca²⁺) constituents. Concentration of HCOO - in surface snow exhibited large variability, ranging from 0.04 to 6.8 μeq L^-1, attributed to dominant contribution from biomass burning emissions. Ion balance (ΔC) and Na⁺/Cl^- calculations indicated an excess of cations (particularly higher Ca²⁺ concentrations) and Cl^- in snow, considering the sea-salt ratio, respectively. Monsoon season (June-September) ion concentrations in snowpit samples were generally two-fold lower than in other seasons. Principal component analysis was used to identify different sources of ions. Three main factors, accounting for more - 42 - than 80% of the total variance, were related to different sources, including agricultural activities, biomass burning, and crustal aerosols.

10 illus, 4 tables, 63 ref

010485   Nath S;Kotal S D;Kundu P K (India Meteorological Dep, , Mausam Bhavan, Lodi Road, New Delhi-110 003, Email: saulnov07@gmail.com) : Decadal variation of ocean heat content and tropical cyclone activity over the Bay of Bengal. J Earth Syst Sci 2016, 125(1), 65-74.

The upper ocean heat content up to 700 m depth (OHC₇₀₀) is an important climatic parameter required for atmospheric and oceanographic studies like a cyclone. In this study, therefore, an attempt has been made to examine the inter-decadal variations of tropical cyclone (TC) activity and OHC₇₀₀ over the Bay of Bengal (BOB) for the post-monsoon season (October-December) during 1955-2013 periods. The sea-surface temperature (SST), geopotential height at 500 hPa, low-level vorticity at 850 hPa, vertical wind shear between 200 and 850 hPa, middle tropospheric humidity at 500 hPa and outgoing long-wave radiation are also being studied using seasonal mean data. The results show a significant inter-decadal variation during 1955-2013, with two distinct decadal periods: active decadal period (ADP) (1955-1988) and inactive decadal period (IDP) (1989-2013). The anomalies of these parameters are opposite in phase for two periods. It is found that the large scale atmospheric features and oceanic parameters have significant inter-decadal variability, but frequency of the tropical cyclone is attributed to the variation in the atmospheric dynamic and thermodynamic conditions rather than the variation of oceanic parameters OHC₇₀₀ and SSTs during the post-monsoon season.

9 illus, 1 table, 40 ref

010484   Maheswaran G;Selvarani A G;Elangovan K (NO, , VSA School of Management, NH-47, Main Road, Uthamasolapuram, Salem-636 010, Email: geethacivil1201@gmail.com) : Groundwater resource expliration in Salem district, Tamil Nadu using GIS and remote sensing. J Earth Syst Sci 2016, 125(2), 311-28.

Since last decade, the value per barrel of potable groundwater has outpaced the value of a barrel of oil in many areas of the world. Hence, proper assessment of groundwater potential and management practices are the needs of the day. Establishing relationship between remote sensing data and hydrologic phenomenon can maximize the efficiency of water resources development projects. Present study focuses on groundwater potential assessment in Salem district, Tamil Nadu to investigate groundwater resource potential. At the same, all thematic layers important from ground water occurrence and movement point of view were digitized and integrated in the GIS environment. The weights of different parameters/themes were computed using weighed index overlay analysis (WIOA), analytic hierarchy process (AHP) and fuzzy logic technique. Through this integrated GIS analysis, groundwater prospect map of the study area was prepared qualitatively. Field verification at observation wells was used to verify identified potential zones and depth of water - 41 - measured at observation wells. Generated map from weighed overlay using AHP performed very well in predicting the groundwater surface and hence this methodology proves to be a promising tool for future.

12 illus, 8 tables, 64 ref

010483   Krishnamoorthy C;Deo Kumar;Balaji C (NO, Indian Institute of Technology Madras, Chennai-600 036, Email: balaji@iitm.ac.in) : Retrieval of humidity and temperature profiles over the oceans from INSAT 3D satellite radiances. J Earth Syst Sci 2016, 125(2), 217-30.

In this study, retrieval of temperature and humidity profiles of atmosphere from INSAT 3D-observed radiances has been accomplished. As the first step, a fast forward radiative transfer model using an Artificial neural network has been developed and it was proven to be highly effective, giving a correlation coefficient of 0.97. In order to develop this, a diverse set of physics-based clear sky profiles of pressure (P), temperature (T) and specific humidity (q) has been developed. The developed database was further used for geophysical retrieval experiments in two different frameworks, namely, an ANN and Bayesian estimation. The neural network retrievals were performed for three different cases, viz., temperature only retrieval, humidity only retrieval and combined retrieval. The temperature/humidity only ANN retrievals were found superior to combined retrieval using an ANN. Furthermore, Bayesian estimation showed superior results when compared with the combined ANN retrievals.

20 illus, 5 tables, 19 ref

010482   Kocak I;Koc S (Geological Engineering Dep, Bozok Univ, 06100, Tandogan, Ankara, Turkiye, Email: ismail.kocak@bozok.edu.tr) : Geochemical characteristics of Kirka (Sarikaya) borate deposit, northwestern Anatolia, Turkey. J Earth Syst Sci 2016, 125(1), 147-64.

The Kirka borate deposit was deposited in a Miocene lacustrine basin which is closely associated with volcanic activity which lasted from Paleogene to the beginning of Quaternary. Borate mineralization alternates with claystone, mudstone, tuff and fine-layered limestone and mostly shows a lenticular structure. The mineral paragenesis is composed of borax, tincalconite, ulexite, kurnakovite, probertite, tunellite, colemanite, dolomite, smectite group minerals, illite and some firstly reported minerals for the Kirka deposit including - 40 - hydrochloroborite, brianroulstonite, hilgardite-4M and searlesite minerals. In comparison to average values of earth crust, concentrations of Cs, Sr, Li, As and Se were significantly enriched with respective rates of 21, 15, 14, 3 and 188 folds. Regarding KY, KS1 and KS2 locations, there are differences in both element abundances and their geochemical tendencies which are attributed to variations in discharge regime and physico-chemical conditions of the depositional environment. Independent behaviour of B₂O₃ might indicate that boron is not associated with clays and carbonates and, therefore, most part of boron must be derived from volcanic activity (hydrothermal solutions, gases). REE data indicate that the Kirka borate deposit was formed in a sedimentary environment where highly alkaline (high pH) hydrothermal solutions also took part in borate precipitation process.

6 illus, 3 tables, 48 ref

010481   Gzam M;El Mejdoub N;Jdeoui Y (U.R. Applied Hydrosciences, Higher Institute of Water Sciences and Teachnics, Gabes Univ, Zrig 6072 Gabes, Tunisia, Email: gzammaher79@gmail.com) : Late quaternary sea level changes of gabes coastal plain and shelf: identification of the MIS 5c and MIS 5a onshore highstands, southern Mediterranean. J Earth Syst Sci 2016, 125(1), 13-28.

The continental shelf of the Gulf of Gabes is outlined, during the MIS 5c and MIS 5a onshore highstands, by the genesis of forced regressive beach ridges situated respectively at -19 m b.s.l/100 ka and -8 m b.s.l/80 ka. This area, considered as a stable domain since at least the last 130 ka (Bouaziz et al. 2003), is a particular zone for the reconstruction of the late quaternary sea-level changes in the region. Shuttle Radar Topography Mission (SRTM) data and field observations are highlighted to deduce interaction between hydrodynamic factors and antecedent topography. Variations in geomorphology were attributed to geological inheritance. Petrography and sedimentary facies of the submerged coastal ridges reveal that the palaeocoastal morphology was more agitated than today and the fluvial discharges are consistent. Actual morphologic trend deduced from different environment coasts (sandy coasts, sea cliffs and tidal flat) is marked by accumulation of marine sands and progradation.

9 illus, 4 tables, 46 ref

010480   Ghannadpour S S;Hezarkhani A (Mining & Metallurgical Engineering Dep, Amirkabir Univ of Technology (Tehran Polytechnic), 424 Hafez Ave, 15875-4413, Tehran, Iran, Email: ardehez@aut.ac.ir) : Introducing 3D U-statisic method for separating anomaly from background in exploration geochemical data with associated software development. J Earth Syst Sci 2016, 125(2), 387-401.

The U-statistic method is one of the most important structural methods to separate the anomaly from the background. It considers the location of samples and carries out the statistical analysis of the data without judging from a geochemical point of view and tries to separate subpopulations and determine anomalous areas. In the present study, to use U-statistic method in three-dimensional (3D) condition, U-statistic is applied on - 39 - the grade of two ideal test examples, by considering sample Z values (elevation). So far, this is the first time that this method has been applied on a 3D condition. To evaluate the performance of 3D U-statistic method and in order to compare U-statistic with one non-structural method, the method of threshold assessment based on median and standard deviation (MSD method) is applied on the two example tests. Results show that the samples indicated by U-statistic method as anomalous are more regular and involve less dispersion than those indicated by the MSD method. So that, according to the location of anomalous samples, denser areas of them can be determined as promising zones. Moreover, results show that at a threshold of U = 0, the total error of misclassification for U-statistic method is much smaller than the total error of criteria of x_+ n x s. Finally, 3D model of two test examples for separating anomaly from background using 3D U-statistic method is provided. The source code for a software program, which was developed in the MATLAB programming language in order to perform the calculations of the 3D U-spatial statistic method, is additionally provided. This software is compatible with all the geochemical varieties and can be used in similar exploration projects.

12 illus, 4 tables, 30 ref

010479   Fu J C;Hsu M H;Duann Y (NO, National Science & Technology Center for Disaster Reduction, New Taipei (ROC), Email: jcfu@ncdr.nat.gov.tw) : Development of roughness updating based on artificial neural network in a river hydraulic model for flash flood forecasting. J Earth Syst Sci 2016, 125(1), 115-28.

Flood is the worst weather-related hazard in Taiwan because of steep terrain and storm. The tropical storm often results in disastrous flash flood. To provide reliable forecast of water stages in rivers is indispensable for proper actions in the emergency response during flood. The river hydraulic model based on dynamic wave theory using an implicit finite-difference method is developed with river roughness updating for flash flood forecast. The artificial neural network (ANN) is employed to update the roughness of rivers in accordance with the observed river stages at each time-step of the flood routing process. Several typhoon events at Tamsui River are utilized to evaluate the accuracy of flood forecasting. The results present the adaptive n-values of roughness for river hydraulic model that can provide a better flow state for subsequent forecasting at significant locations and longitudinal profiles along rivers.

8 illus, 3 tables, 30 ref

010478   Bingsong Y U;Zhuang R;Cong Z;Yinglu P; Changsong L;Lidong W (State Key Laboratory of Geological processes and Mineral Resources, China Univ of Geosciences, 100083, Beijing, P.R. China, Email: ruanz0103@cugb.edu.cn) : Tectonic evolution of tarim - 38 - basin in cambrian-ordovician and its implication for reservoir development, NW China. J Earth Syst Sci 2016, 125(2), 285-300.

In order to find the impact of regional tectonic evolution of Tarim basin on the inside distribution of sedimentary facies and reservoir development, this paper, based on the research of plate-tectonic evolution of Tarim basin, conducts an in-depth analysis on the basin's inside sedimentary response to the Eopaleozoic regional geodynamic reversion from extension to convergence around Tarim plate, and concludes that the regional geodynamic environment of surrounding areas closely contributes to the formation and evolution of paleo-uplifts, differentiation of sedimentary facies in platform, distribution of high-energy reef and bank facies belts, conversion of sedimentary base level from fall to rise, obvious change of lithology from dolomite to limestone, and formation of several unconformity surfaces in Ordovician system in the basin. A series of sedimentary responses in the basin are controlled by regional dynamic setting, which not only controls the distribution of reservoirs in reef and bank facies but also restricts the development and distribution of karst reservoirs controlled by the unconformity surfaces. This offers the macro geological evidences for us to further analyze and evaluate the distribution of favorable reservoirs.

15 illus, 1 table, 44 ref