ID: 56257
Title: Hydrogeologic, electrical and electromagnetic measurements for geotechnical characterization of foundation beds at Afunbiowo, near Akure, Southwestern Nigeria
Author: I A Adeyemo and O G Omosuyi
Editor: Prof Natarajan Gajendran
Year: 2012
Publisher: Indian Society for Education and Environmetn (iSee), Vol 5, Issue: 2, February 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Indian Journal of Science and Technology
Keywords: Hydrogeology, water, bedrock, geophysical survey, Afunbiowo, Akur, Nigeria
Abstract: In order to evaluate layer competence for civil engineering foundation, engineering geophysical surveys (electromagnetic profiling and resistivity soundings), and hydrogeologic measurements, involving determination of depths to water table across wells, were conducted at Afunbiowo, near Akure, Nigeria. The EM raw real values vary from -44.0 to 49.9, while filtered real values vary from -43.8 to 48.5 across the study area. The Karous-Hjelt and Fraser filtered (KHF) pseudo-sections suggest the presence of clay and weathered materials in the central parts of the area. The interpretation of the geoelectrical data reveals that the near surface materials overlying the crystalline bedrock exhibit significant variations of resistivity values, ranging from 29 to 1400 ohm-m, while the bedrock resistivity ranges from 96 to 24729 ohm-m. This interpretation correlates with the high EM anomalies across the area. A pronounced low resistivity zone in the shallow subsurface is associated with saturated sands or clay rich sand. Depth to water table various from 0.3 m to 7.5 m, with an average level of 4.5 m . Water table occurs at shallow depths in the southwestern, central and north central segments of the area. Since a raised water table, or clay saturated with water may create a wet foundation and consequently engender geotechnical instability, building foundations in the southwestern, central and north central segments of the area must be founded on watertight concrete base.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56256
Title: Methods of analysing missing values in a regression model
Author: P Ogoke Uchenna and E C Nduka
Editor: Prof Natarajan Gajendran
Year: 2012
Publisher: Indian Society for Education and Environmetn (iSee), Vol 5, Issue: 2, February 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Indian Journal of Science and Technology
Keywords: Missing at random, imputation, Bartlett ' s Test, Coefficient of Relative Variance
Abstract: Different methods of imputation are adopted in this study to compensate for missing values encountered in the data collected. The imputation methods considered are the overall mean value, Random Overall, Logistic Regression, Linear Regression, Predictive Match, Multiple Imputations and the Hot Deck Imputation. The various values obtained by the methods were analysed and compared using Bartlett ' s test statistic for equality of variances among groups (Mean Square Errors of the seven methods). The software packages used for this research work are Winmice, Solas and SAS. Different values were estimated applying the various methods. However, results obtained from the test showed that the variances among the groups have no significant differences, that is, any of the imputation methods could be used. Further test using relative variance revealed that the multiple imputation method may be preferred.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56255
Title: Inter-decadal trends in the annual cycles of atmospheric CO2 at Mauna Loa
Author: K S Yajnik and P S Swathi
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 102, No 5, 10 March 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Annual cycles, atmospheric carbon dioxide, industrial emissions, inter-decadal trend
Abstract: Cyclical rise and fall of monthly mean CO2 concentration occurred rather regularly at Mauna Loa, Hawaii, USA, during 1958-2008, with peaks occurring in April or May followed by troughs in September or October. However, the frequency of troughs in September increased from 32% in 1958-1974 to 82% in 1992-2008 and the depletion season correspondingly decreased from 4.8 months on average to 4.2 months. Does this seemingly small change in the seasonal rhythm point to changes on an inter-decadal scale in the CO2 accumulation rates? This question is studied here by examining linear and exponential trends of seasonal and annual CO2 accumulation rates in three equal phases (1958-1974, 1975-1991 and 1992-2008). We also discuss trend of average accumulation rates in the accretion and depletion seasons, and of the amplitude and standard deviation of the annual CO2 cycles at Mauna Loa, which can be viewed as representative of the North Central Tropical Pacific.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56254
Title: Need for proper water management for food security
Author: S K Tyagi, P S Datta and Ravender Singh
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 102, No 5, 10 March 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Food grains, food security, irrigation water, population growth, groundwater
Abstract: In India, for food security, the future agriculture faces the challenge of enhancing crop production under uncertain climatic extremes, in a limited (or degraded at many places) land area, with more and more requirement of water (in many places, poor quality water), complexities and rapid erosion of natural biodiversity and agricultural systems, and the socio-economic systems governing food supply and demand. Plant attributes conferring good yields, under fast-depleting/deteriorating natural resource base, are yet to be identified. Breeding for crop improvement, for higher quality, production, heat and water stress resistance, has met with limited success. It is well known that despite plantign the improved genetic varieties, and application of the recommended doses of fertilizers and agronomic practices, the dormant seed gets its vigour only in the presence of water. But, reliable assessment of this important resource base and its protection from depletion and degradation has not received its due consideration in the management of agricutlure. In this context, analyses of agricultural information reported in the literature, clearly suggest that proper water management can only help in enhancing future food production. Policy guidelines have also been suggested for ensuring food security.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56253
Title: Possible contribution of River Saraswati in groundwater aquifer system in Western Rajasthan, India
Author: D S Mitra and Balram Bhadu
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 102, No 5, 10 March 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Aquifers, lineaments, neotectonics, Palaeochannel, subsurface ridge
Abstract: River Saraswati is believed to have flown through the Thar Desert, as reconstructed by several experts based on critical data gathered by them. A careful observation of the channel shows that in most of the places these are fault-controlled. Studies of palaeochannels in many parts of the world proved successful in identifying high-yielding freshwater zones. Presence of fault system accelerates the recharge process and down-flow of water gets maximized through fault planes during the wet period. The present work is an attempt to emphasize the contribution of palaeo Saraswati River to groundwater exploration in drought-prone areas of western Rajasthan.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56252
Title: Stone alignment with solar and other sightlines in South India
Author: Srikumar M Menon, Mayank N Vahia, Kailash Rao
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 102, No 5, 10 March 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56251
Title: Land use/land cover changes in the catchment of water bodies in and around Davangere city, Karnataka
Author: Nafeesa Begum, J Narayana and Arun Kumar S L
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Scrub land, built up land, fallow land, catchments area, false colour composite, remote sensing, Geographic Information System
Abstract: Land use/land cover changes around four water bodies situated in and near Davangere city (Karnataka) during the period 1970-2005 were analysed using satellite data and Survey of India Topo maps. Using Geographical Information System (GIS), the detailed analysis revealed that the area under agriculture and settlements increased whereas the scrub land decreased around TV - station reservoir. Around Yelebethur lake, the built up land area increased and the scrubland has been converted to agricultural land. Land cover around Bathi lake also recorded an increase in built up land whereas Hadadi lake surrounding show increased agricultural land and a decline in fallow land.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56250
Title: Fluvial environment of Jiadhal river basin, Dhemaji district, Assam
Author: Uzzal Mani Hazarika
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Flow, gauge, discharge, sediment, flood frequency, flood
Abstract: The Jiadhal river is a flashy river, which is tributary of Brahmaputra. 3848 mm is the maximum annual rainfall and 874.91 m3s-1 is the maximum flow found in the basin during the study period. 98.93 m is the water level corresponding to the maximum flow occurred in the year 1990. Whereas, 4.7 m3s-1 is the annual minimum flow and 95.88m is the corresponding water level recorded in the year 1991. It is observed that the maximum annual discharges have shown a decreasing trend whereas similar trend is not observed in the case of minimum annual discharge of the river. Correlation study shows higher variation in case of maximum discharge whereas low variation is found in case of minimum discharge. The flood frequency analysis made using aek/E factor methods reveals that the Log-Pearson Type III, for which D-index value is found lowest and hence is the most appropriate method for estimating the design flood of any return period. Because of the flashy nature of flow the river, it has devastating impacts like flood, erosion and sedimentation. Total damage (in Rs) due to flood ranges from 0.033 crores in 1997 to as high as 14. 123 crores in 2002. Maximum area was affected in 1998, whereas in 1994 and 1995 the affected area was maximum. Therefore, it influenced socio-economy of humans and ecology of the basin. In the present paper the fluvial enviornment of the river basin has been presented.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56249
Title: A perspective on watershed development in the Central Himalayan State of Uttarakhand, India
Author: Malavika Chauhan
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Drought prone area programme, integrated watershed development project, livelihoods, Sukho Majri, Sustainable development, Watershed concept
Abstract: This paper discusses the evolution of watershed development projects and their implementation in the central Himalayan state of Uttarakhand in India. It traces the historical growth of thinking on watershed in the region, and highlights issues and influences. Impacts and benefits discussed in relation to sustainability. The review shows that success in these projects is usually isolated, mostly seen in small micro-watersheds with naturally good water harvesting conditions. Overall, the results and impacts of watershed programmes in the region have been vastly disproportionate to financial and technical inputs, usually because benefits are slow, gradual and unevenly distributed. The involvement of NGOs, which bring a strong social organizational aspect to the activities, brought necessary focus to the programmes. However, in some areas unhealthy levels of community dependence on NGOs are visible, losing the long-term sustainability factor. Gaps in the understanding of technical aspects including hydrogeological issues, changing livelihood and landuse patterns, and upstream-downstream linkages continue to undermine possible impacts. However, watershed programmes are evolving with time, adapting and streamlining thinking and processes, and lessons learned are being used in the design and development of future programmes.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56248
Title: Effects of red tide on physico-chemical properties of water and phytoplankton assemblage in Sepanggar Bay, Sabah, Malaysia
Author: Md Rashed-Un-Nabi, Low Sin Ee, Md. Azharul Hoque, Madihah Jaffar Sidik, Ejriah Saleh and Ann Anton
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Harmful Algal bloom, Similarity percentage, cluster analysis, multidimensional scaling
Abstract: Harmful algal bloom (HAB) produced by Cochlodinium sp. is a serious concern in the west coast of Sabah in Malaysia. Recently frequent occurrence of red tide has been reported in Sepanggar Bay, south of Kota Kinabalu. This paper presents a comparative study of physico-chemical properties of water and phytoplankton assemblage during red tide and non-red tide period in Sepanggar Bay. Measured parameters were significantly different (p<0.05) between the red tide and non-tide periods. The mean abundances of phytoplankton was 0.388 x 106 cells L and 1.628 x 106 cells during cells during red tide and non-red tide period respectively. The global R value, obtained through analysis of similarity test, in non-red tide period (0.03) were higher than in the red tide period (0.01) which indicates more diverse phytoplankton assemblage during non-red tide period. Cochlodinium sp. was the most discriminating species (31.39%) during red tide period and Coscinodiscuss sp. (18.25%) during the non-red tide period. Through cluster analysis three species groups were found during red tide period while six groups were found during non-red tide period, which implies less diverse phytoplankton assemblage in the presence of red tide.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56247
Title: Soil aggregate carbon and diversity of mycorrhiza as affected by tillage practices in a rice-wheat cropping system in Northern India
Author: Neelam A Aggarwal, Asha Gaur, Ekta Bhalla and S R Gupta
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Conventional tillage, zero-tillage, furrow irrigated raised bed tillage, soil aggregates, AM spore density, AM root colonization
Abstract: This study analyses the effect of tillage practices on organic carbon storage in soil aggregates and the diversity of arbuscular mycorrhizal (AM) fungi in a rice-wheat cropping system (located at Uchana, 29051 ' N and 760 57 ' E) in northern India. The rice crop was grown under conventional tillage (CT) and the wheat crop under conventional tillage (CT), zero-tillage (ZT) and furrow irrigated raised bed (FIRB) tillage systems. After seven years, soil organic carbon was: zero-tillage, 0.61%; conventional tillage, 0.44% and FIRB 0.35%. In the zero-tillage (ZT) and furrow irrigated raised bed (FIRB) tillage systems, microaggregates (< 250? m to 53? m) formed 48.47 to 61.64% of total soil aggregates fractions and protected most of organic carbon and nitrogen in the soil. The clay and silt fractions of the soil (<53 ?m) varied from 39.58 to 49.26% in different tillage systems.
The total number of arbuscular mycorrhizal (AM) fungal spores in the soil under wheat crop at different depths was: 1.3 - 7.5 g-1 soil ZT and 1.2 - 9.3 g-1 soil FIRB. The species richness of AM fungal spores was greater during the wheat growing season than during the rice crop. The AM fungal root colonization was: 13.22 to 68.16% in rice crop and 17.60 to 87.78% in wheat crop. The AM fungal root colonization in both wheat and rice was greater at 0 -15 cm soil depth. The relative density of the AM fungal spores under different tillage practices in wheat crop was: 7.58 - 18.31% Acaulospora sp., 5.04-11.38% Gigaspora sp., 67.00 - 83.3% Glomus sp. and 3.86 - 5.75% other species.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56246
Title: Benthic insect-substratum relationship along an altitudinal gradient in a Himalayan stream, India
Author: Agmohan Singh, O P Gusain and Manju P Gusain
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Benthic insects, substratum, Phi scale, seasonal distribution, Garhwal Himalaya
Abstract: Takoli Gad is a small spring -fed tributary of the River Alaknanda (a tributary of River Ganga) in Tehri district of Uttarakhand (India). Insect-substratum relationship was studied at five sampling sites representing an altitudinal gradient in Takoli Gad during January 2000 to February 2002. The swift flowing stream is largely dominated by pebbles and boulders (> 32 mm). In general, the substrate composition ranged from coarse sand (phi = 0) to small pebbles (phi = -4). The benthic fauna comprised of 34 genera belonging to 09 orders and 25 families of insects. It included mostly the nymphs and larvae of Ephemerotpera, Plecoptera, Trichoptera, Coleoptera, Lepidoptera, Odonata, Neuroptera, Diptera and Hemiptera. The total benthic density was maximum during winter III (3408.0 ind. m-2) at downstream site, and minimum during monsoon I (283.0 ind.m-2) in the middle stretch. The Simpson Index of Diversity (D) for substrate heterogeneity was low for headwater region of the stream. The Index of Representation (IR) revealed that the heterogeneous substratum was the preferred habitat of most of the taxa during the winter. The distribution of the benthic insects varied slightly along the longitudinal gradient. Many genera were seasonally absent in different sections of the stream. Seasonal variation in the density of benthic insects was correlated with the change in the substrate composition, notably during the rainy season when the mean grain size changes to cobbles (Md = 8). A relatively stable substrate composition during winter together with low to moderate current velocity (0.4 - 0.6 m s-1) and shallow water depth (0.14 - 0.20 m) along with abundant detritus favours a rich and diverse insect community. Further, clustering method also shows the substratum during winter to be perferred by majority of the taxa.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56245
Title: Two-hundred year changes in plant-species composition; A case study of Madras city in the Coromandel coast, Peninsular India
Author: Anantanarayanan Raman
Editor: B. Gopal, P S Pathak, A Raman, S Y Lee
Year: 2010
Publisher: National Institute of Ecology, Vol 36, No 4, December 2010
Source: Centre for Ecological Sciences
Reference: None
Subject: International Journal of Ecology and Environmental Sciences
Keywords: Disappearance and Survival of Plant taxa, eighteenth century, Madras, Rottle, Tranquebar Mission, vegetation, Willdenow, 200 year history
Abstract: Peter Johann Rottler (1749-1836) came from Strasbourg (Alsace) and joined the Tranquebar Mission in the Coromandel (Cozhamandalam) in peninsular India in 1776. During his stay here, he pursued the plants of this region driven by his passion to know medicinal plants. On a road trip from Tranquebar northwards to Madras and back, Rottler collected plants, and this plant-collection activity has been scientifically documented in a paper entitled Botanische Bemerkungen auf der Hin- und Ruckreise von Trankenbar nach Madras vom Herrn Missionair Rottler zu Trankenbar mit anmerkugen von Professor C.L. Willdenow published in the Gesellschaft Naturforschender Freunde zu Berlin [Neue Schriften] in 1803. Using the information available in this article, we have compared Madras-city vegetation with data extracted from two Madras-flora volumes published in 1929 and 1994, thus highlighting the plants of Madras in the eighteenth century. We the authors of the present article bring to light the changes that have occurred in the last 200 years in terms of loss of species, by verifying changes to plant-species composition in Madras city and its immediate neighbourhood, and relate the reasons for these changes. Between 1803 and 1929, maximum species loss had occurred. Of the 81 species (80 to be precise, because of species synonymy in recent times) species recorded in 1803, only 33 exist in the 1929 record, indicating loss of 47 taxa. Between 1929 and 1994, besides the 33 reported in 1929, ten ' new ' additional taxa were recorded. As of today, the loss of economically important plants such as Mimosa chundra (Mimosaceae) and Costus speciosus (Zingiberaceae) appears irreversible and is discomforting, whereas the continued existence of the ' sensitive ' taxon Habenaria viridiflora (Orchidaceae) is comforting.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 56244
Title: Urban vegetation detection using radiometrically calibrated small-footprint full-waveform airborne LiDAR data
Author: Bernhard Hofle, Markus Hollaus, Julian Hagenauer
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 67, January 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Laser scanning, LiDAR, Calibration, Vegetation, Object based image analysis, full-waveform
Abstract: This paper introduces a new GIS workflow for urban vegetation mapping from high-density (50 pts/m2) full-waveform airborne LiDAR data, combining the advantages of both raster and point cloud based analysis. Polygon segments derived by edge-based segmentation of the normalized digital surface model are used for classification. A rich set of segment features based on the point cloud and derived from full-waveform attributes is built, serving as input for a decision tree and artificial neural network (ANN) classifier. Exploratory data analysis and detailed investigation of the discriminative power of selected point cloud and full-waveform LiDAR obervables indicate a high value of the occurrence of multiple district targets in a laser beam (i.e. ' echo ratio ' ) for vegetation classification (98% correctness). The radiometric full-waveform observables (e.g. backscattering coefficient) do not suffice as single discriminators with low correctness values using a decision tree classifier (< 72% correctness) but higher values with ANN (< 95% correctness). Tests using reduced point densities indicate that the derived segment features and classification accuracies remain relatively stable even up to a reduction factor of 10 (5 pts/m2). In a representative study area in the City of Vienna/Austria the applicabiliyt of the developed object-based GIS workflow is demonstrated. The unique high density full-waveform LiDAR data open a new scale in 3D object characterization but demands for novel joint strategies in object-based r aster and 3D point cloud analysis.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 56243
Title: Relative INS/GNSS aerial control in integrated sensor orientation: Models and performance
Author: M Blazquez, I Colomina
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 67, January 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: GNSS, INS, relative, integrated sensor orientation
Abstract: In this paper we present the models and discuss the performance of relative position and attitude INS/GNSS aerial control observations in integrated sensor orientation. In relative aerial control, we use the relative position and attitude of the IMU at the exposuer times of successive images instead of the usual absolute position and attitude for each image. With relative aerial control, the GNSS shift correction parameters and the IMU-to-camera boresight matrix vanish from the functional models and so does the problem of their selection. The presented models are formulated with the usual original INS/GNSS attitude parameterisation (heading, pitch and roll) to avoid unnecessary and error-prone intermediate re-parameterisation steps. Furthermore, we present a rigorous model formulation, for both aerial control and photogrammetric observations, in local mapping coordinate systems that eliminate the need of the so-called height and azimuth corrections and that guarantee geodetic correctness and consistency. The overall resulting modelling scheme allows for a direct incorporation of INS/GNSS aerial control observations into the integrated sensor orientation processing chain in a simple and robust way. The performence of the new models is evaluated with three independent data sets and the results show a comparable to better performance.
Location: 231
Literature cited 1: None
Literature cited 2: None