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61.
Baseline metals pollution profile of tropical estuaries and coastal waters of the Straits of Malacca
Ley Juen Looi Ahmad Zaharin Aris Wan Lutfi Wan Johari Fatimah Md. Yusoff Zailina Hashim 《Marine pollution bulletin》2013
The status report on metal pollution in tropical estuaries and coastal waters is important to understand potential environmental health hazards. Detailed baseline measurements were made on physicochemical parameters (pH, temperature, redox potential, electrical conductivity, salinity, dissolved oxygen, total dissolved solid), major ions (Na, Ca, Mg, K, HCO3, Cl, SO4 and NO3) and metals concentrations (27Al, 75As, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se, 66Zn) at estuaries and coastal waters along the Straits of Malacca. Principal component analysis (PCA) was employed to reveal potential pollution sources. Seven principal components were extracted with relation to pollution contribution from minerals-related parameters, natural and anthropogenic sources. The output from this study will generate a profound understanding on the metal pollution status and pollution risk of the estuaries and coastal system. 相似文献
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Jiban K. Sarker Mehedi Ahmed Ansary Md. S. Rahman A. M. M. Safiullah 《Environmental Earth Sciences》2010,60(3):643-653
Mymensingh municipality lies in one of the most earthquake-prone areas of Bangladesh. The town was completely destroyed during
the Great Indian Earthquake of 12 June 1897, for which the surface-wave magnitude was 8.1. In this study the 1897 Great Indian
Earthquake was used as a scenario event for developing seismic microzonation maps for Mymensingh. For microzonation purposes
SPT data from 87 boreholes were collected from different relevant organizations. To verify those data ten boreholes of depth
up to 30 m were drilled. Intensity values obtained for different events were calibrated against attenuation laws to check
applicability to the study area. Vibration characteristics at diverse points of the study area were estimated by employing
the one-dimensional wave-propagation software SHAKE. SHAKE discretizes the soil profile into several layers and uses an iterative
technique to represent the non-linear behavior of the soil by adjusting the material properties at each iteration step. The
required input information includes depth, shear wave velocity, damping factor, and unit weight of each soil layer. The liquefaction
resistance factor and the resulting liquefaction potential were estimated to quantify the severity of liquefaction. Quantification
of secondary site effects and the weighting scheme for combining the various seismic hazards were heuristic, based on judgment
and expert opinion. 相似文献
64.
A modified Rankine source panel method is presented for solving a linearized free-surface flow problem with respect to the double-body potential. The method of solution is based on the distribution of Rankine sources on the hull as well as its image and on the free surface. An iterative algorithm is used for determining the free surface and wave resistance using upstream finite difference operator. A verification of numerical modeling is made using the Wigley hull and the validity of the computer program is examined by comparing the details of wave profiles and wave making resistance with Series 60 model. 相似文献
65.
T. M. Hunse K. Md. Najeeb K. Rajarajan M. Muthukkannan 《Journal of the Geological Society of India》2010,75(5):704-708
Presence of high levels of Radon (222Rn) gas was reported from groundwater in Bangalore. To ascertain the ground reality and the nature of the hazards, if any,
a study was conducted by the Central Ground Water Board, Bangalore in and around Bangalore city. Groundwater samples from
borewells and a dug well were collected and analysed. Available data on Radon gas from both groundwater and surface water
sources were also compared. The presence of Radon gas and its concentration in groundwater were examined with respect to geology
and well depths. The results are discussed in the paper. 相似文献
66.
Md. Sharwar Murshed Sangil Kim Jeong-Soo Park 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(7):897-911
The beta-κ distribution is a distinct case of the generalized beta distribution of the second kind. In previous studies, beta-p and beta-κ distributions have played important roles in representing extreme events, and thus, the present paper uses the
beta-κ distribution. Further, this paper uses the method of moments and the method of L-moments to estimate the parameters
from the beta-κ distribution, and to demonstrate the performance of the proposed model, the paper presents a simulation study
using three estimation methods (including the maximum likelihood estimation method) and beta-κ and non beta-κ samples. In
addition, this paper evaluates the performance of the beta-κ distribution by employing two widely used extreme value distributions
(i.e., the GEV and Gumbel distributions) and two sets of actual data on extreme events. 相似文献
67.
Geospatial and geostatistical approach for groundwater potential zone delineation 总被引:1,自引:0,他引:1 下载免费PDF全文
Javed Mallick Chander Kumar Singh Hussein Al‐Wadi Mohd Ahmed Atiqur Rahman Satyanarayan Shashtri Saumitra Mukherjee 《水文研究》2015,29(3):395-418
Over the past few decades, groundwater has become an essential commodity owing to increased demand as a result of growing population, industrialization, urbanization and so on. The water supply situation is expected to become more severe in the future because of continued unsustainable water use and projected change in hydrometeorological parameters due to climate change. This study is based on the integrated approach of remote sensing, geographical information system and multicriteria decision‐making techniques to determine the most important contributing factors that affect the groundwater resources and to delineate the groundwater potential zones. Ten thematic layers, namely, geomorphology, geology, soil, topographic elevation (digital elevation model), land use/land cover, drainage density, lineament density, proximity of surface water bodies, surface temperature and post‐monsoon groundwater depth, were considered for the present study. These thematic layers were selected for groundwater prospecting based on the literature; discussion with the experts of the Central Ground Water Board, Government of India; field observations; geophysical investigation; and multivariate techniques. The thematic layers and their features were assigned suitable weights on Saaty's scale according to their relative significance for groundwater occurrence. The assigned weights of the layers and their features were normalized by using the analytic hierarchy process and eigenvector method. Finally, the selected thematic maps were integrated using a weighted linear combination method to create the final groundwater potential zone map. The final output map shows different zones of groundwater potential, namely, very good (16%), good (35%), moderate (28%) low (17%) and very low (2.1%). The groundwater potential zone map was finally validated using the discharge and groundwater depth data from 28 and 98 pumping wells, respectively, which showed good correlation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
68.
Najat Qader Omar Mohd Sanusi S. Ahamad Wan Muhd Aminuddin Wan Hussin Narimah Samat Siti Zubaidah Binti Ahmad 《Journal of the Indian Society of Remote Sensing》2014,42(1):165-178
The cellular automata (CA) model is an important tool in land use change studies. Swift increases in population and long-term expectations of rapid urbanization have led to extensive land use change, and normal living conditions have affected the natural resources of the land. This paper highlights and analyzes the historical urban changes in Kirkuk City, Iraq, considering repeated changes undergone by the state such change as government infrastructures, wars, and economic blockade. In this paper, an integrated model, built-in multi regression model, and multi-criteria evaluation were considered to improve the representation of CA transition rules. Environmental and socioeconomic factors were used to produce Suitable Maps (SMs). These SMs were practicalities to create factor layers and weight usage, rating method process for variance expert decision-making groups, and geographic information systems for the periods 1984, 1990, 2000, and 2010. The roots of the equation (R2) values are compared and these values are chosen to produce a good model of suitable maps. The approach used in this study provides a mechanism for monitoring suitability maps in Kirkuk. Furthermore, the model Markov CA is implemented and evaluated. The results indicate that the model, its related concepts performs sufficiency 相似文献
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