Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): assessment for multi-domestic purposes     

Mohd S. Abu Jabal  Ismail Abustan  Mohd Remy Rozaimy  Hussam El Najar 《Arabian Journal of Geosciences》2017,10(12):257

The present study research investigation is aimed to assess the groundwater quality for the urban area in Khan Younis City, southern Gaza Strip, for multi-domestic purposes. The physicochemical analysis of the groundwater wells shows the major ions in the order of Na⁺ > Mg²⁺ > Ca²⁺ > B³⁺ > K⁺ and Cl^? > HCO₃ ^? > SO₄ ^2? > NO₃ ^2? > F^? > PO₄ ^3?. Groundwater quality is classified as very hard-brackish water type. Ninety-five percent of the wells are classified as saline water type with high NO₃ ^2? concentrations. Based on water quality index (WQI), the groundwater falls into one of three categories: fair water (10%), poor water (15%), very poor (45%), and worst (30%). The high WQI values are because of high Na⁺, Cl^?, SO₄ ^2?, and NO₃ ^2? concentrations, while synthetic pollution index (SPI) values indicate that most about 80% of the wells are seriously polluted. Langelier Saturation Index (LSI) indicates that most of data are either slightly scale forming or corrosive water or slightly corrosive but non-scale forming, and 75% of the wells are suitable for construction purposes (have SO₄ ^2? concentrations <300 mg/L). The groundwater reaches alarming situation, where almost chemically unsuitable for drinking purposes and the water to be used after proper treatment such as desalination.  相似文献   

SWAT manual calibration and parameters sensitivity analysis in a semi-arid watershed in North-western Morocco     

Youssef Brouziyne  Aziz Abouabdillah  Rachid Bouabid  Lahcen Benaabidate  Ons Oueslati 《Arabian Journal of Geosciences》2017,10(19):427

Being a laborious approach, manual calibration of hydrologic model in a semi-arid context requires in-depth knowledge of the watershed and as much as possible field input data to obtain reliable simulations. In this study, manual calibration and relative sensitivity analysis approaches of the SWAT model (Soil and Water Assessment Tool) were applied for water balance in a 1993 km² watershed (on the R’dom river) located in North-western Morocco. The watershed is located in a semi-arid area dominated by agro-forestry activities. The objectives of this study were (i) to perform a local sensitivity analysis of the SWAT model taking into consideration the watershed characteristics and (ii) to implement a detailed methodology of manual calibration and validation of the model in a semi-arid context. Sensitivity analysis has been carried out on 12 different SWAT input parameters, and has revealed that 4 input parameters only were the most influential ones on flow components of the R’dom watershed. Model manual calibration was conducted along 2006 and 2007 by comparing measured and predicted monthly and daily discharges and taking Nash-Sutcliffe coefficient (NSE), determination coefficient (R ²), and percent bias (PBIAS) as goodness-of-fit indicators. Validation has been performed by the same approach through 2008 and 2009 period. All final NSE values were above 0.5, R ² values exceeded 0.7, and PBIAS lower than 25% demonstrating satisfactory model performances over the study watershed conditions. The SWAT model set-up with measured input data, manually calibrated and validated, reflects well the real hydrologic processes occurring in the R’dom watershed and can be used to assess current and future conditions and to evaluate alternative management practices.  相似文献   

Variation in the life-history traits of a Schilbid catfish,Clupisoma garua (Hamilton, 1822) in the coastal waters of southern Bangladesh     

Siddik  Muhammad Abu Bakar  Chaklader  Md Reaz  Hanif  Md Abu  Nahar  Ashfaqun  Ilham  Ilham  Cole  Anthony  Fotedar  Ravi 《中国海洋湖沼学报》2017,35(5):1189-1196

For the first time,the present study reports the life-history traits,comprising length-frequency distribution(LFD),sex ratio(SR),length-weight relationships(LWRs),condition factors(CFs),and relative growth(W_R),of Clupisoma garua in the coastal waters of Bangladesh.A total of 150 specimens ranging from 8.60 to 25.20 cm total length(TL)and 4.26 to 128.80 g body weight(BW)were collected using traditional fishing gear from August 2013 to July 2014.The overall sex ratio of males to females in the study did not dif fer significantly from the expected value of 1:1(χ~2=0.96,P0.05)but there were significant sex differences(P0.05)in the intercepts and slopes of graphs characterizing traits in C.garua.The calculated bvalues for the LWRs were 2.955,2.893 and 2.927 for males,females and combined sexes,respectively,and there was negative allometric growth in all cases(b3).The condition factors(K_A,K_F,K_R)and relative growth(W R)also did not differ significantly(P0.05)between the sexes.This study provides a useful tool for fi shery specialists to evaluate the relative condition of fish and to initiate early management strategies and regulations for the sustainable management of the remaining stocks of this species in the entire coastal region of southern Bangladesh.  相似文献   

Surface electrical resistivity tomography and hydrogeological characterization to constrain groundwater flow modeling in an agricultural field site near Ferrara (Italy)     

Micòl Mastrocicco  Giulio Vignoli  Nicolò Colombani  Nasser Abu Zeid 《Environmental Earth Sciences》2010,61(2):311-322

A portion of an unconfined alluvial aquifer located in the Padana Plain (Italy) was characterized following an integrated hydro-geophysical approach. Initially an electrical resistivity tomography (ERT) survey was employed to localize the boundaries of a modest paleo-channel body and to design the installation of a groundwater monitoring network. Multilevel slug-tests were performed to estimate the aquifer’s saturated hydraulic conductivities. Determined permeability values together with electrical resistivity data were correlated. The correlation resulted in a site specific bi-logarithmic linear relationship. Based on this relationship, punctually determined hydraulic conductivities were spatially extended over the studied flow domain. Finally, continuously measured piezometric heads were used to calibrate a 3D flow model. Sensitivity analysis was performed to confirm the reliability of the reconstructed permeability field, as well as, to assess the minimum number of direct measurements needed to safely characterize the selected aquifer portion. The integration of the ERT survey results with the classical hydrogeological tests can be conveniently applied to constrain the permeability field during flow model calibration. Although the applicability of the determined relationship is site specific, the followed procedure is useful especially when there is a need to optimize the available resources and in case of small-scale pilot studies.  相似文献   

The best fitting distribution of annual maximum rainfall in Peninsular Malaysia based on methods of L-moment and LQ-moment     

Wan Zawiah Wan Zin  Abdul Aziz Jemain  Kamarulzaman Ibrahim 《Theoretical and Applied Climatology》2009,96(3-4):345-345

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Spatial patterns and trends of daily rainfall regime in Peninsular Malaysia during the southwest and northeast monsoons: 1975–2004     

Jamaludin Suhaila  S. M. Deni  Wan Zawiah Wan Zin  Abdul Aziz Jemain 《Meteorology and Atmospheric Physics》2010,106(1-2):1-18

Model precipitation can be produced implicitly through convective parameterization schemes or explicitly through cloud microphysics schemes. These two precipitation production schemes control the spatial and temporal distribution of precipitation and consequently can yield distinct vertical profiles of heating and moistening in the atmosphere. The partition between implicit and explicit precipitation can be different as the model changes resolutions. Within the range of mesoscale resolutions (about 20 km) and cumulus scale, hybrid solutions are suggested, in which cumulus convection parameterization is acting together with the explicit form of representation. In this work, it is proposed that, as resolution increases, the convective scheme should convert less condensed water into precipitation. Part of the condensed water is made available to the cloud microphysics scheme and another part evaporates. At grid sizes smaller than 3 km, the convective scheme is still active in removing convective instability, but precipitation is produced by cloud microphysics. The Eta model version using KF cumulus parameterization was applied in this study. To evaluate the quantitative precipitation forecast, the Eta model with the KF scheme was used to simulate precipitation associated with the South Atlantic Convergence Zone (SACZ) and Cold Front (CF) events. Integrations with increasing horizontal resolutions were carried out for up to 5 days for the SACZ cases and up to 2 days for the CF cases. The precipitation partition showed that most of precipitation was generated by the implicit scheme. As the grid size decreased, the implicit precipitation increased and the explicit decreased. However, as model horizontal resolution increases, it is expected that precipitation be represented more explicitly. In the KF scheme, the fraction of liquid water or ice, generated by the scheme, which is converted into rain or snow is controlled by a parameter S ₁. An additional parameter was introduced into KF scheme and the parameter acts to evaporate a fraction of liquid water or ice left in the model grid by S ₁ and return moisture to the resolved scale. An F parameter was introduced to combine the effects of S ₁ and S ₂ parameters. The F parameter gives a measure of the conversion of cloud liquid water or ice to convective precipitation. A function dependent on the horizontal resolution was introduced into the KF scheme to influence the implicit and explicit precipitation partition. The explicit precipitation increased with model resolution. This function reduced the positive precipitation bias at all thresholds and for the studied weather systems. With increased horizontal resolution, the maximum precipitation area was better positioned and the total precipitation became closer to observations. Skill scores for all events at different forecast ranges showed precipitation forecast improvement with the inclusion of the function F.  相似文献   

Spatial trends of dry spells over Peninsular Malaysia during monsoon seasons   总被引：1，自引：0，他引：1  

Sayang Mohd Deni  Jamaludin Suhaila  Wan Zawiah Wan Zin  Abdul Aziz Jemain 《Theoretical and Applied Climatology》2010,99(3-4):357-371

This study aims to trace changes in the dry spells over Peninsular Malaysia based on the daily rainfall data from 36 selected rainfall stations which include four subregions, namely northwest, west, southwest, and east for the periods of 1975 to 2004. Six dry spell indices comprising of the main characteristics of dry spells, the persistency of dry events, and the frequency of the short and long duration of dry spells will be used to identify whether or not these indices have increased or decreased over Peninsular Malaysia during the monsoon seasons. The findings of this study indicate that the northwestern areas of the Peninsular could be considered as the driest area since almost all the indices of dry spells over these areas are higher than in the other regions during the northeast (NE) monsoon. Based on the individual and the field significant trends, the results of the Mann–Kendall test indicate that as the total number of dry days, the maximum duration, the mean, and the persistency of dry days are decreased, the trend of the frequency of long dry spells of at least 4 days is also found to decrease in almost all the stations over the Peninsula; however, an increasing trend is observed in the frequency of short spells in these stations during the NE monsoon season. On the other hand, during the southwest monsoon, a positive trend is observed in the characteristics of dry spells including the persistency of two dry days in many stations over the Peninsula. The frequency of longer dry periods exhibits a decreasing trend in most stations over the western areas during both monsoon seasons for the periods of 1975 to 2004.  相似文献   

The effect of surface profile, rock strength and pretension load on bending behaviour of fully grouted bolts     

Hossein Jalalifar  Naj Aziz  Muhammad Hadi 《Geotechnical and Geological Engineering》2006,24(5):1203-1227

Fully encapsulated rock bolting has, in recent years, become a universally accepted system of ground reinforcement in mining and tunnel construction. The application of bolting systems extends both to rebar as well as cable bolting. The effectiveness of the bolt application has been studied in shear, both by laboratory tests as well as by numerical modeling. A specially constructed double shearing apparatus (DSA) was used to examine the shearing behaviour of a bolt installed perpendicularly across two joints. The experimental study was complemented with three-dimensional numerical analysis. Parameters examined include, the effect of reinforced material on tension/compression zones along the sheared bolt, shear resistance, shear displacement and induced strains and stresses during bolt bending process. The study was undertaken at both free load and pretension conditions. The conclusions drawn from the study were the level of bolt resistance to shear was influenced by bolt profile configuration, the strength of the rock or medium influenced the level of load generated on the bolt and the increased bolt pretension contributed to increased shearing load of the bolted medium. The numerical simulation of the bolt/medium interaction and deformational behaviour were found to be in close agreement with the experimental test results.  相似文献   

Efficient real-time reservoir management using adjoint-based optimal control and model updating   总被引：2，自引：0，他引：2  

Pallav Sarma  Louis J. Durlofsky  Khalid Aziz  Wen H. Chen 《Computational Geosciences》2006,10(1):3-36

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Electrical geophysical and hydrogeological investigations of groundwater aquifers in Ruseifa municipal landfill, Jordan     

E. Al-Tarazi  A. El-Naqa  M. El-Waheidi  J. Abu Rajab 《Environmental Geology》2006,50(7):1095-1103

The effect of the Ruseifa municipal landfill on the shallow groundwater aquifers in the area was investigated in two separate sites. The first one was not used since 1994, whereas the other is still being used for dumping. Fourteen electrical resistivity soundings were performed to detect the leachate and its effect on the quality of the groundwater. Results indicated that the solid waste thickness of the landfill was ranged from 3 to 20 m with resistivity value less than 10 Ω m. Based on the resistivity decreases of values less than 5 Ω m, the leachate was detected in the landfill sites at depths ranged from 10 to 50 m. However, the flow direction of the leachate at depth ranging 10–20 m in the terminated site was toward north, whereas the flow direction of the leachate in the site still used for dumping was toward east–northeast which causes the major source of groundwater pollution.  相似文献