Spatial Distribution and Anthropogenic Assessment of Heavy Metals in the Surface Sediments of Klang River     

Abolfazl Naji  Ahmad Ismail 《湿地科学》2011,9(1):8-18

The study was conducted to quantify the concentration and distribution of metals (Cd, Zn, Ni, Cu, Pb, and Fe) in the surface sediments and to assess the status of metal contaminations in the Klang River, Malaysia. The concentrations of metals (μg∕g, Fe%, dry weight) were as follows: 0.57-2.19 μg∕g Cd; 31.89-272.33 μg∕g Zn; 5.96-24.47 μg∕g Ni; 10.57-52.87 μg∕g Cu; 24.23-64.11 μg∕g Pb and 1.56%-3.03% Fe. Sequential extraction technique (SET) showed that mean anthropogenic portions of metals were in the order of Zn (60.22%), Cu (56.01%), Cd (45.63%), Ni (42.08%), Pb (33.22%) and Fe (10.26%). The highest concentrations of metals ( p<0.05) were found in the stations located close to industrial parks and highly populated areas. The results of the present study showed that the effectiveness of total organic carbon (TOC) contents in controlling the distribution and enrichment of metals was a more important factor compared to grain size. The study also indicated that the control of metals pollution from direct influx of domestic wastes and insufficiently treated industrial wastes in the Klang River was an important and desirable way to minimize the detrimental effects of metals.  相似文献   

Heavy metal concentrations in sediments off Bintulu, Malaysia   总被引：1，自引：0，他引：1  

Ahmad Ismail 《Marine pollution bulletin》1993,26(12):706-707

  相似文献   

Water Problems in Gaza Strip,Palestine     

Ismail ALGHALBAN 《东北亚地学研究》2001,(2)

ＩｎｔｒｏｄｕｃｔｉｏｎＧａｚａｓｔｒｉｐｉｎｓｏｕｔｈｅｒｎＰａｌｅｓｔｉｎｅ (Ｆｉｇ .1 )ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｃｒｉｔｉｃａｌａｒｅａｓａｒｏｕｎｄｔｈｅｗｏｒｌｄ .Ｔｈｅａｒｅａｉｓａｂｏｕｔ365ｋｍ2 ｗｉｔｈａｐｏｐｕｌａｔｉｏｎａｂｏｕｔ  相似文献   

Engineering Properties, Microstructure and Strength Development of Lightweight Concrete Containing Pumice Aggregates     

A. I. M. Ismail  M. S. Elmaghraby  H. S. Mekky 《Geotechnical and Geological Engineering》2013,31(5):1465-1476

Lightweight aggregate concretes are widely incorporated in construction and development. This study presented an experimental investigation on the engineering properties of volcanic pumice lightweight aggregates concretes. Three groups of lightweight concretes: 1—coarse pumice aggregates (2–6 mm), 2—course pumice aggregates (2–6 mm)/sand size pumice aggregates and 3—course pumice aggregates (2–6 mm)/sand fraction were built and the physical/mechanical aspects of them were studied. The results of the compressive strength, density, water absorption, pH and shrinkage showed that these lightweight concretes were affected by the type of aggregates, the cement paste and the interfacial zone between cement and aggregates. One grain size pumice (2–6 mm) showed best compressive strength (65 kg/cm²), density of 0.60 g/cm³, linear shrinkage 0.4 % and high water absorption 29.73 %. Strength minerals represented by calcium-silicate-hydrate (CSH) and calcium-aluminate-hydrate (CAH) leading the concrete strength.  相似文献   

Implementation of method of lines to predict water levels due to a storm along the coastal region of Bangladesh   总被引：2，自引：0，他引：2  

Gour Chandra Paul  Ahmad Izani Md. Ismail  Md. Fazlul Karim 《Journal of Oceanography》2014,70(3):199-210

In this study, the method of lines (MOL) has been applied to solve two-dimensional vertically integrated shallow water equations in Cartesian coordinates for the prediction of water levels due to a storm surge along the coast of Bangladesh. In doing so, the partial derivatives with respect to the space variables were discretized by the finite difference (central) method to obtain a system of ordinary differential equations (ODEs) with time as independent variable. The classical fourth-order Runge–Kutta method was used to solve the obtained system of the ODEs. We used a nested finite difference scheme, where a high resolution fine grid model (FGM) capable of incorporating all major islands along the coastal region of Bangladesh was nested into a coarse grid model (CGM) covering up to 15°N latitude of the Bay of Bengal. The boundaries of the coast and islands were approximated through proper stair step. Appropriate tidal condition over the model domain was generated by forcing the sea level to be oscillatory with the constituent M ₂ along the southern open boundary of the CGM omitting wind stress. Along the northeast corner of the FGM, the Meghna River discharge was taken into account. The developed model was applied to estimate water levels along the coast of Bangladesh due to the interaction of tide and surge associated with the April 1991 storm. We also computed our results employing the standard finite difference method (FDM). Simulated results show the MOL performs well in comparison with the FDM with regard to CPU time and stability, and ensures conformity with observations.  相似文献   

Effects of additional HONO sources on visibility over the North China Plain   总被引：1，自引：1，他引：0  

Ying Li  Junling An  Ismail Gultepe 《大气科学进展》2014,31(5):1221-1232

The objective of the present study was to better understand the impacts of the additional sources of nitrous acid （HONO） on visibility, which is an aspect not considered in current air quality models. Simulations of HONO contributions to visibility over the North China Plain （NCP） during August 2007 using the fully coupled Weather Research and Forecasting/Chemistry （WRF/Chem） model were performed, including three additional HONO sources： （1） the reaction of photo-excited nitrogen dioxide （NO~） with water vapor; （2） the NO2 heterogeneous reaction on aerosol surfaces; and （3） HONO emissions. The model generally reproduced the spatial patterns and diurnal variations of visibility over the NCP well. When the additional HONO sources were included in the simulations, the visibility was occasionally decreased by 20%-30% （3-4 km） in local urban areas of the NCP. Monthly-mean concentrations of NO3, NH＋, SO]- and PM2.5 were increased by 20%-52% （3-11μg m-3）, 10%-38%, 6%-10%, and 6%-11% （9-17 μg m-3）, respectively; and in urban areas, monthly-mean accumulation- mode number concentrations （AMNC） and surface concentrations of aerosols were enhanced by 15%-20% and 10%-20%, respectively. Overall, the results suggest that increases in concentrations of PM2.5, its hydrophilic components, and AMNC, are key factors for visibility degradation. A proposed conceptual model for the impacts of additional HONO sources on visibility also suggests that visibility estimation should consider the heterogeneous reaction on aerosol surfaces and the enhanced atmospheric oxidation capacity due to additional HONO sources, especially in areas with high mass concentrations of NOx and aerosols.  相似文献   

Livelihood diversification as an adaptation approach to change in the pastoral Hindu-Kush Himalayan region   总被引：1，自引：0，他引：1  

Ning Wu  Muhammad Ismail  Srijana Joshi  Shao-liang Yi  Ritu Meher Shrestha  Abdul Wahid Jasra 《山地科学学报》2014,11(5):1342-1355

Migratory livestock raising has been one of the most important livelihood options for people residing in high mountain areas and has made a significant contribution to the economy of the Hindu Kush Himalayan（HKH） region, both in terms of supporting households and in export earnings. However, in recent decades, changes in the socioeconomic situation and increasing climate variability have led to a need to enhance adaptation by building the resilience of local socio-ecological systems, including economic diversification and sustainable management of natural resources. Based on semistructured interviews with pastoral communities in six countries within the pastoral HKH region, this paper discusses the situation, trends and driving forces behind the diversification of pastoral livelihood. For internal diversification the study highlights the need for enhancement of pastoral livelihoods through value-adding activities in the pastoral sectors. For external diversification changes on policy changes are needed to support free out-migration, market exploitation, and multiple resource use. Finally the paper highlights the role of education in determining household adaptation strategies in the face of various socio-ecological pressures and recommends integrating innovative and indigenous knowledge to develop appropriate methods for risk management and resource management in the pastoral HKH region.  相似文献   

Determination of Critical Factors in Implementing River Clean‐Up Projects: A Malaysian Case Study     

Zubaidah Ismail  Khatijah Salim 《洁净——土壤、空气、水》2013,41(1):16-23

Fast economic growth of a country contributes to the increase of activities that can also bring negative impacts on the rivers. Contamination of rivers, sedimentation, coastal erosion, decrease of aquatic life, and also flooding are some of these universal impacts. There are several rivers around the world, which are categorized as very polluted and require cleaning‐up operations. Several factors have been identified to be influencing factors in the success or otherwise of the implementation and operation of these projects. This study examined the factors related to the steps taken to clean‐up and rehabilitate these rivers and deduce by utilizing factor analysis the most critical success factors from the results obtained. A responsible river community is by far the most effective way to keep a river basin clean. Very often, however, cleaning‐up operations are necessary to revive and maintain the quality of the river so that it can be save to use as an important source of water for human consumption. It was found that community awareness was the most critical cluster of factors determining the success of the clean‐up work.  相似文献   

The cumulative impacts of reclamation and dredging on the marine ecology and land-use in the Kingdom of Bahrain   总被引：1，自引：0，他引：1  

Zainal K  Al-Madany I  Al-Sayed H  Khamis A  Al Shuhaby S  Al Hisaby A  Elhoussiny W  Khalaf E 《Marine pollution bulletin》2012,64(7):1452-1458

This article assesses the ecological and economic impacts of land reclamation and dredging through consulting recent environmental impact assessment reports. Geographic features of Bahrain during 1963-2008 are produced using Geographical Information System. Extensive but inexpensive shallow coastal areas and tidal flats have been reclaimed particularly from 1997 to 2007 at a high rate of 21 km(2)/year. Formal records show the increase in the original land mass by the year 2008 to be 91 km(2). An estimated total cumulative loss of major habitats resulting from 10 reclamation projects was around 153.58 km(2). Also much larger scale impacts should be considered resulting from the borrow areas used for the extraction of sand or infill materials. A number of key habitats and species are affected in the vicinity of these projects. The study attempts to assign a monetary value to the marine ecosystem functions. There is a need for efficient coastal zone management to regulate a sustainable use of the marine resources.  相似文献   

Seasonal occurrence and microhabitat of the hyperparasitic monogenean Udonella fugu on the caligid Copepod Pseudocaligus fugu infecting the grass puffer Takifugu niphobles in the Seto Inland Sea, Japan     

Hiroko Okawachi  Susumu Ohtsuka  Norshida Binti Ismail  B. A. Venmathi Maran  Kazuo Ogawa 《Ocean Science Journal》2012,47(3):181-187

The seasonal occurrence and microhabitat of the monogenean Udonella fugu that hyperparasitizes exclusively on adults of the caligid copepod Pseudocaligus fugu that infects the skin of the grass puffer Takifugu niphobles were investigated in the Seto Inland Sea, western Japan from November 2004 to December 2006. The udonellids occurred and bred mostly during the occurrence of P. fugu on the fish host. The average prevalence and intensity of U. fugu on P. fugu during the whole investigation were 29% and 3.6, respectively. The main attachment sites of U. fugu were the posterior side of leg 3 and the dorsal marginal side of the cephalothorax for feeding and copulation, while eggs were predominantly located on the ventral side of the urosome to avoid detachment. More attention should be paid to the ecology of U. fugu, due to recent high prevalence of P. fugu on cultured tiger puffer in western Japan.  相似文献