Displaying publications 161 - 180 of 509 in total

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  1. Hamidreza Salemi, Mohd Amin Mohd Soom, Lee, Teang Shui, Mohd Kamil Yusoff
    MyJurnal
    One of the most interesting water management case studies in Iran is the case of Zayandehrud River, the main river that supplies water to Isfahan Province which is located in Gavkhuni River Basin (GRB). This paper examines the present and future demands for water and determines the extent to which water will be available for agricultural use by the year 2020. Although demand and supply conditions in 2000 were more or less in balance, there was an increase in the supply of some 28% by 2010 due to the completion of the third trans-basin diversion and the development of other local water sources. However, the demand exceeded its supply in 2010 and the basin fell into severe deficit. In this condition, the only way to keep supply and demand in balance is to reduce allocations to agriculture. By 2020, agriculture would only have 5% more water than the present and water supply is only 90% that of the normal, and this would then shrink from 2025 onwards. In other words, agriculture would have to be sacrificed in order to ensure full supplies of water for the other sectors. The scenarios examined reveal that a sustainable agriculture can only be accomplished by water saving practices and management measures, which may further lead to reduced demand, control supplies, and improve the efficiency of water use.
    Matched MeSH terms: Rivers
  2. Yuhani Jamian, Zainap Lamat, Nurazura Rali
    MyJurnal
    Sungai Sarawak is the most important river in Sarawak. This study was aimed at assessing water quality in the selected stations from Satok bridge to the downstream, Muara Tebas, located along Sungai Sarawak. Water quality trend analysis was conducted to determine the correlation between the water quality parameters. Trend analysis was carried out using Mann-Kendall Test because data collected was non-parametric. Next, Spearman rank was used in order to determine the correlation between parameters. The results obtained and the observation made in this study reveals that the trend exists only for Chemical Oxygen Value (COD). But there are trends for Biochemical Oxygen Demand, (BOD), Dissolved Oxygen (DO), Total Suspended Solid (TSS), Ammoniacal Nitrogen (NH4N) and Turbidity to decrease or increase with no trends between 2007 and 2011. The correlation between parameters is not very strong because there are many determinants of water quality parameters. The result from this study would provide useful information for water quality management in order to maintain and improve the water quality of Sungai Sarawak.
    Matched MeSH terms: Rivers
  3. Mahboubeh Ebrahimian, Ahmad Ainuddin Nuruddin, Mohd Amin Mohd Soom, Alias Mohd Sood, Liew Juneng
    MyJurnal
    The hydrological effects of climate variation and land use conversion can occur at various spatial scales, but the most important sources of these changes are at the regional or watershed scale. In addition, the managerial and technical measures are primarily implemented at local and watershed scales in order to mitigate adverse impacts of human activities on the renewable resources of the watershed. Therefore, quantitative estimation of the possible hydrological consequences of potential land use and climate changes on hydrological regime at watershed scale is of tremendous importance. This paper focuses on the impacts of climate change as well as land use change on the hydrological processes of river basin based on pertinent published literature which were precisely scrutinized. The various causes, forms, and consequences of such impacts were discussed to synthesize the key findings of literature in reputable sources and to identify gaps in the knowledge where further research is required. Results indicate that the watershed-scale studies were found as a gap in tropical regions. Also, these studies are important to facilitate the application of results to real environment. Watershed scale studies are essential to measure the extent of influences made to the hydrological conditions and understanding of causes and effects of climate variation and land use conversion on hydrological cycle and water resources.
    Matched MeSH terms: Rivers
  4. Grismer LL, Wood PLJ, Ahmad AB, Baizul-Hafsyam BS, Afiq-Shuhaimi M, Rizal SA, et al.
    Zootaxa, 2018 May 29;4425(1):87-107.
    PMID: 30313468 DOI: 10.11646/zootaxa.4425.1.5
    Two new species of diminutive, sympatric, lowland, leaf-litter skinks of the genus Tytthoscincus Linkem, Diesmos Brown from the Sekayu region of Hulu Terengganu, Terengganu State in northeastern Peninsular Malaysia are described on the basis genetic and morphological data. One of the new species, T. monticolus sp. nov., was collected in a hilly riparian area along Sungai (=river) Bubu and is most closely related to an undescribed species from the Tembak Reservoir area. The other, T. keciktuek sp. nov. collected along Sungai Peres, is most closely related to T. perhentianensis Grismer, Wood, Grismer from Pulau (=island) Perhentian Besar. Sympatry and syntopy of multiple, specialized, unrelated, leaf-litter species of Tytthoscincus was previously only known from upland areas and these new species represent the first example of lowland of sympatry. More importantly, however, these endemic species add to a growing body of research and discoveries that continue to underscore the unrealized biodiversity of the riparian systems of Hulu Terengganu and the Sekayu region and their need for protection and continued study.
    Matched MeSH terms: Rivers
  5. Shaharudin Abdul Razak
    A study of the major Arthropoda taxa of invertebrates recolonizing Saraca roots occurring on various substrates and under various water velocities was carried out in the upper reaches of the Gombak River. The sites for the recolonization experiments were selected in the fast and slow flowing sections of rocks and boulders, sand and gravel and mud and silt biotopes. The Hydropsychidae and the Nemouridae were the pioneer recolonizers of Saraea roots in the fast flowing sections of the stream whereas the Ptilodactylidae and the Caenidae were the pioneer recolonizers in the slow flowing sections of the stream.
    Suatu kajian telah dijalankan bagi menentukan takson utama invertebrata Arthropoda yang mengkoloni semula akar Saraca yang didapati pada pelbagai substrat dan pada kelajuan air yang berbeza di bahagian hulu Sungai Gombak. Tapak-tapak untuk ujikaji pengkolonian-semula telah dipilih pada bahagian laju dan perlahan biotop batuan besar dan sederhana, pasir dan batuan kecil, dan lumpur dan kelodak. Hydropsychidae dan Nemouridae adalah pengkoloni perintis pada akar Saraca di bahagian aliran laju sungai sementara Ptilodactylidae dan Caeflidae adalah pengkoloni perintis di bahagian aliran perlahan sungai itu.
    Matched MeSH terms: Rivers
  6. Ibrahim Jaafar, Zalina Awang, Shahriza Shahrudin, Shahrul Anuar Md Sah, Nur Hafizah Ibrahim, Amirah Hurzaid, et al.
    Sains Malaysiana, 2012;41:691-696.
    Bukit Perangin Forest Reserve, Kedah Malaysia is a popular forest park well known for its clear rivers and streams, interesting sedimentary rock formations and a rich biodiversity in flora and fauna. However to date no report on the amphibians and reptiles of this forest has ever been published. Therefore, from January 2009 to May 2010, herpetofauna surveys were conducted at Bukit Wang Recreational Forest, which forms a part of the Bukit Perangin Forest Reserve. The results of the survey showed that a total of 15 species of amphibians belonging to 6 families and 15 species of reptiles
    belonging to 7 families were found in the study area. These constitute the first records for the amphibians and reptiles in this forest. The herpetofauna checklist showed that the most abundant amphibians were from the family Ranidae while the most abundant reptiles were from the family Gekkonidae.
    Matched MeSH terms: Rivers
  7. Mohsen Salarpour, Milad Jajarmizadeh, Zulkifli Yusop, Fadhilah Yusof
    Sains Malaysiana, 2014;43:1865-1871.
    The modeling of rainfall-runoff relationship in a watershed is very important in designing hydraulic structures, controlling flood and managing storm water. Artificial Neural Networks (ANNs) are known as having the ability to model nonlinear mechanisms. This study aimed at developing a Generalized Feed Forward (GFF) network model for predicting annual flood (depth) of Johor River in Peninsular Malaysia. In order to avoid over training, cross-validation technique was performed for optimizing the model. In addition, predictive uncertainty index was used to protect of over parameterization. The governing training algorithm was back propagation with momentum term and tangent hyperbolic types was used as transfer function for hidden and output layers. The results showed that the optimum architecture was derived by linear tangent hyperbolic transfer function for both hidden and output layers. The values of Nash and Sutcliffe (NS) and root mean square error (RMSE) obtained 0.98 and 5.92 for the test period. Cross validation evaluation showed 9 process elements is adequate in hidden layer for optimum generalization by considering the predictive uncertainty index obtained (0.14) for test period which is acceptable.
    Matched MeSH terms: Rivers
  8. Norizah K, Mohd. Hasmadi I
    Sains Malaysiana, 2012;41:1177-1185.
    In hilly forest area, aligning forest roads is the key towards an effective and sustainable forest management. Constraints in forest road planning are mainly due to environmental factors and topographical conditions. Selecting the criteria for planning forest road and setting the priorities, ranking them for environmental sustainability and reduce cost in road construction is important. Different criteria are required at different forest area since the quantifiable relationship between cause and effect to meet the goal are not comprehensively prioritized. In order to solve the problem, the relative importance factor from multi criteria basis, namely Analytic Hierarchy Process (AHP) was applied. Therefore, the objective of this study was to develop priorities and rank a selected criterion for planning forest road in hilly area using AHP approach. Four criteria had been identified to meet the goal of suitable forest road allocation namely slope, river crossing, elevation and existing forest road. The suitable criteria selected were sorted with weight in ranking order to minimize the impact of timber harvesting. Our results showed that the priorities and ranking were as follows; slope (w = 0.558), followed by river crossing (w = 0.303), elevation (w = 0.095) and lastly existing forest road (w = 0.044), respectively. Therefore, the relative preference factor developed in this study can be used by the Forestry Department for formulating suitable forest road allocation in hilly area simultaneously to be integrated with geographic information system technology.
    Matched MeSH terms: Rivers
  9. Mehmood OU, Norzie Mustapha, Sharidan Shafie, Hayat T
    Sains Malaysiana, 2014;43:1109-1118.
    This research looks at the effects of partial slip on heat and mass transfer of peristaltic transport. The magnetohydrodynamic (MHD) flow of viscous fluid in a porous asymmetric channel has been considered. The exact solutions for the stream function, longitudinal pressure gradient, longitudinal velocity, shear stress, temperature and concentration fields are derived by adopting long wavelength and small Reynolds number approximations. The results showed that peristaltic pumping and trapping are reduced with increasing velocity slip parameter. Furthermore, temperature increases with increasing thermal slip parameter. Moreover, the concentration profile decreases with increasing porosity parameter, Schmidt number and concentration slip parameter. Comparisons with published results are found to be in good agreement.
    Matched MeSH terms: Rivers
  10. Kok K, Kim JC
    Sci Total Environ, 2019 Apr 01;659:1209-1223.
    PMID: 31096334 DOI: 10.1016/j.scitotenv.2018.12.398
    This study presents a theoretical framework based on power law distribution to identify the vulnerable regions to soil loss in Susu river basin at Cameron Highlands, Malaysia by using the geomorphologic factors from Digital Elevation Model (DEM). Drainage area is used to describe the runoff aggregation structure of the watershed which represents the magnitude of discharge. Stream power is also used to describe the energy expenditure pattern of the watershed. They are fitted to power law distribution by means of the maximum likelihood to estimate the threshold for soil loss. The landscape stability condition is assessed through the mechanism of channel initiation. Two regions in the slope area plot are recognized as the regimes susceptible to soil loss, in that discharge, local slope and energy are sufficient for the initiation of soil movement. The result is further improved by incorporating the Topographic Wetness Index (TWI) aiming to locate vulnerable regions to soil loss under the dynamic saturation process. The final result indicates that the vulnerable regions expand from perennial reaches to ephemeral reaches as saturation process develops. It implies the transition of runoff generation from groundwater in perennial reaches to surface runoff in ephemeral reaches. Identification of soil loss vulnerable regions under the dynamic saturation process helps in planning of the mitigation measures for soil erosion.
    Matched MeSH terms: Rivers
  11. Norshidah Baharuddin, Nor'ashikin Saim, Sharifuddin M. Zain, Hafizan Juahir, Rozita Osman, Aziah Aziz
    Sains Malaysiana, 2014;43:1355-1362.
    Water pollution has become a growing threat to human society and natural ecosystem in recent decades, increasing the need to better understand the variabilities of pollutants within aquatic systems. This study presents the application of two chemometric techniques, namely, cluster analysis (CA) and principal component analysis (PCA). This is to classify and identify the water quality variables into groups of similarities or dissimilarities and to determine their significance. Six stations along Kinta River, Perak, were monitored for 30 physical and chemical parameters during the period of 1997-2006. Using CA, the 30 physical and chemical parameters were classified into 4 clusters; PCA was applied to the datasets and resulted in 10 varifactors with a total variance of 78.06%. The varifactors obtained indicated the significance of each of the variables to the pollution of Kinta River.
    Matched MeSH terms: Rivers
  12. Alias J, Mat N
    Jurnal Psikologi Malaysia, 2011;olume 25:22-25.
    Personal ups and downs are appropriate responses to the ups and downs of life. However, some experiences emotional extremes in moods and disturbed their normal life. Individuals who have depression at times and mania or hypomania at others are called manic-depressive; and the combination is known as manic-depressive psychosis (MDP). This paper attempts to look at manic-depressive psychosis (MDP) from the western approaches as well as from the Islamic point of view. The treatments proposed by both streams are also provided.
    Matched MeSH terms: Rivers
  13. Nather Khan I, Firuza Begham Mustafa
    Sains Malaysiana, 2010;39:189-198.
    Spatial and temporal variations in silica concentration were determined at various rivers and tributaries in the Linggi River Basin, which has been highly polluted due to urban, industrial and agricultural wastes. The silica content measured as reactive silicate in the whole Linggi River Basin ranged from 1.4 to 26.3 mg/L. A clear seasonal variation in silica was noted especially in the major rivers with higher concentration during dry months and lower concentration during the wet months. The concentration was found to decrease as the water flooded downstream. The large drainage area with granite dominated lithology and high denudation especially in the upper catchment is attributed for high silica content in the water of Linggi River Basin.
    Matched MeSH terms: Rivers
  14. Hossain M
    Sains Malaysiana, 2010;39:157-159.
    On 3 January 2008, one specimen of Goonch Bagarius yarrelli (Sykes 1839) (Siluriformes: Sisoridae) was caught by a conventional beach seine in the lower part of the Ganges River, NW Bangladesh. The specimen constitutes a new record of maximum length and weight for the Ganges River and the South Asia.
    Matched MeSH terms: Rivers
  15. Ibrahim, M.N., Ismail, W.R., Najib, S.A.M.
    MyJurnal
    Merbok river catchment situated in the Kedah State receives its input from Bongkok River
    and Puntar River flowing down and joining Lalang River to flow down to the Merbok
    Estuary. The Merbok catchment (440 km2) is experiencing several degrees of complex
    land uses activities that poses some impact on the suspended sediment production of
    the Merbok river. A study was conducted to investigate the suspended sediment loading
    of rivers draining the Merbok catchment from January to December 2013. Suspended
    sediment budget of the Merbok catchment were estimated. The river suspended sediment
    concentrations (SSC) and suspended sediment (SS) load increased during wet season
    compared to dry season. The SS loads increases from upper catchment to river mouth. The
    sediment loadings were divided into three segments- the upstream, middle segment and
    lower segment. The SS loads increased from 10 t yr-1 in the upper part of Bongkok river
    to 3336 t yr-1 in upper segment. The sediment loading then increase to 4299 t yr-1 in the
    middle segment of the catchment (at Bongkok 4), and then exiting the Merbok Estuary, as
    the lower segment, with a total amount of sediment output estimated at 7156 t yr-1. From this
    total sediment output, most of the sediment
    source came from the tributaries; the
    Bongkok River at B3 (3337 t yr-1), Puntar
    River (2924 t yr-1) and Lalang River (1370
    t yr-1), which were much higher than its
    proportion in terms of its length and drainage
    area. As a conclusion, the inconsistence in
    SSC in the river were influenced by the
    various anthropogenic activities (especially
    agriculture and urbanization activities) in the catchment area which necessitate future land use and sediment control to avoid sediment
    and possible nutrient loading into the estuary.

    Matched MeSH terms: Rivers
  16. Alkhadher SAA, Kadir AA, Zakaria MP, Al-Gheethi A, Keshavarzifard M, Masood N, et al.
    Mar Pollut Bull, 2020 Apr;153:111013.
    PMID: 32275559 DOI: 10.1016/j.marpolbul.2020.111013
    Linear alkylbenzenes were determined in the surface sediments of Muar River and Pulau Merambong, Peninsular Malaysia. The concentrations ranged from 87.4 ng g-1 to 188.1 ng g-1 and from 67.4 ng g-1 to 98.2 ng g-1 of dry weight, respectively. The composition profiles of LABs were characterized, and sewage treatment levels were identified. The ratios of internal to external isomers (I/E ratios) of the linear alkylbenzenes in Muar River sediments ranged from 1.7 to 2.2, whereas those of Pulau Merambong sediments ranged from 1.6 to 1.7. The calculated LAB ratios indicated that the study areas received primary and secondary sewage effluents. The degradation of linear alkylbenzenes in Muar River ranged from 33% to 43%, and that in Pulau Merambong ranged from 33% to 34%. The higher degradation indices in Muar River are a sign of improvement in wastewater treatment.
    Matched MeSH terms: Rivers
  17. Nuzaima Che Mood, Faridah Othman, Noor Farahain Muhammad Amin, Md. Ibrahim Adham
    Sains Malaysiana, 2017;46:1221-1229.
    Surface water quality monitoring is an important tool for enhancing the water body management system. This study focuses on the water quality of a lake based on rehabilitation work completed in 2014. This lake suffers from eutrophication and water quality degradation due to the increase in pollution rates and water source scarcity. Nine points were selected to represent the water quality status for the study area. Two river tributaries that pass through the University Malaya (UM) campus have been considered due of its potential as a water source for the lake. Field and laboratory analysis were conducted to understand the transport of water quality parameters. The data variations were analyzed using a multivariate statistical method to determine the significant differences between the lake and river. Based on the Malaysian Water Quality Index (WQI) and cluster analysis, the results indicated that the lake and river have different physico-chemical characteristics and the lake water has a better quality than the river. Comparison of the concentration for BOD, TSS, PO43- and NO3- between year 2009 and current study proved that the water quality has improved by 99.8% proving that the lake remediation is effective.
    Matched MeSH terms: Rivers
  18. Dai C, Li S, Duan Y, Leong KH, Tu Y, Zhou L
    Sci Total Environ, 2021 Dec 20;801:149730.
    PMID: 34467938 DOI: 10.1016/j.scitotenv.2021.149730
    Pharmaceuticals in aquatic environment have raised wide attention in recent years due to their potential adverse effects and bioaccumulation in biota. China has been a major producer and consumer of pharmaceuticals, however, the potential human health risk of these chemicals is yet to be determined in China. In this study, we evaluated available exposure data for twenty pharmaceuticals in surface waters from Chinese five major river basins (the Yangtze, Haihe, Pearl, Songliao, and Yellow River Basins), and human health risk assessment was performed. Based on the concentration data and risk data, we conducted research on the source, cause, and control measures of the pharmaceuticals. The twenty pharmaceuticals were found to be ubiquitous in China with median concentrations between 0.09 and 304 ng/L. The estimated daily intake of pharmaceuticals from drinking water and eating fish was calculated. The intake via drinking water was significantly lower than that via eating fish. The risk quotients via water intake and fish consumption ranged from 0 to 17.2, with estrogen and sulfapyridine highest among the twenty pharmaceuticals. High risks of exposure were mainly in North China, including the Haihe and Songliao River Basins. This is the first analysis in Chinese major river basins that has filled the gaps in the research on the human health risks of pharmaceuticals. The results of the study provide basic information of pharmaceutical intake from drinking water and eating fish in China and provide insights into the risk management guidance of pharmaceuticals, and will facilitate the optimization of health advisories and policy making.
    Matched MeSH terms: Rivers
  19. Kurniawan TA, Lo W, Othman MHD, Liang X, Goh HH, Chew KW
    J Environ Manage, 2023 Mar 01;329:117047.
    PMID: 36563449 DOI: 10.1016/j.jenvman.2022.117047
    This study investigated physico-chemical interactions among Cu(II), biogenic materials, and Fe2O3 in a continuous-flow biofilm reactor system under a well-controlled environment. The effects of Fe2O3 and bacterial biofilms on the distribution of Cu(II) in a simulated aquatic environment were studied. To control biological and abiotic elements in the marine environment, a biofilm reactor was designed to understand the metal speciation of Cu(II) and its distribution. The reactor consisted of a biofilm chamber equipped with glass slides for biofilms attachment. Due to its ability to grow as biofilm in the medium, Pseudomonas atlantica was cultivated to adsorb trace Cu(II) to attached and suspended cells. It was found that biofilms with 170-285 mequiv chemical oxygen demand (COD) concentration/m2 of total oxidizable materials accelerated the Cu(II) adsorption to the surface of the reactor significantly by a factor of five. A significant inhibition to the bacterial growth took place (p ≤ 0.05; t-test) when Cu(II) concentration was higher than 0.5 mg/L. In the absence of Cu(II), bacterial cells grew normally to 0.075 of optical density (OD). However, at the Cu(II) concentration of 0.2 mg/L, the cells grew to a lower OD of 0.58. The presence of glycine and EDTA substantially reduced the toxicity of Cu(II) on bacterial growth (p ≤ 0.05; paired t-test). Their complexation with Cu(II) rendered the metal ions less available to bacterial cells. This implies that the Fe2O3 and bacterial biofilm affected Cu(II) distribution and speciation in the aquatic environment.
    Matched MeSH terms: Rivers
  20. Lourdes EY, Low VL, Izwan-Anas N, Dawood MM, Sofian-Azirun M, Takaoka H, et al.
    Parasitol Int, 2023 Jun;94:102733.
    PMID: 36693472 DOI: 10.1016/j.parint.2023.102733
    Mermithids are the most common parasites of black flies and are associated with host feminization and sterilization in infected hosts. However, information on the species / lineage of black fly mermithids in Southeast Asia, including Malaysia requires further elucidation. In this study, mermithids were obtained from black fly larvae collected from 138 freshwater stream sites across East and West Malaysia. A molecular approach based on nuclear-encoded 18S ribosomal RNA (18S rRNA) gene was used to identify the species identity / lineage of 77 nematodes successfully extracted and sequenced from the specimens collected. Maximum likelihood and neighbor-joining phylogenetic analyses demonstrated five distinct mermithid lineages. Four species delimitation analyses: automated simultaneous analysis phylogenetics (ASAP), maximum likelihood Poisson tree processes with Bayesian inferences (bPTP_ML), generalized mixed yule coalescent (GMYC) and single rate Poisson tree processes (PTP) were applied to delimit the species boundaries of mermithid lineages in this data set along with genetic distance analysis. Data analysis supports five distinct lineages or operational taxonomic units for mermithids in the present study, with two requiring further investigation as they may represent intraspecific variation or closely related taxa. One mermithid lineage was similar to that previously observed in Simulium nigrogilvum from Thailand. Co-infection with two mermithids of different lineages was observed in one larva of Simulium trangense. This study represents an important first step towards exploring other aspects of host - parasite interactions in black fly mermithids.
    Matched MeSH terms: Rivers
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