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ISLAM Muhammad RAZZAQ Abdul ZUBAIR Muhammad HASSAN Sawsan AHMAD Sarfraz GUL Shamim RISCHKOWSKY Barbara LOUHAICHI Mounir 《山地科学学报》2022,(1):46-57
Scrub rangelands support livestock grazing and provide ecosystem services to their inhabitants.The present study was conducted in Chakwal,an important tract of ... 相似文献
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M. Hussein A. A. Amer I. I. Sawsan M.Sc. 《International Journal of Environmental Science and Technology》2008,5(2):233-242
In the present work, an attempt was made to provide an efficient, easily deployable method of cleaning up oil spills and recovering of the oil. Carbonized pith bagasse, a relatively abundant and inexpensive material is currently being investigated as an adsorbent to remove contaminants “oil” from water. Fibers extracted from bagasse and carbonized at 300 °C were found to have a high performance for sorption and recovery of light, heavy oils and even the viscous ones. The physical properties of pith bagasse were investigated using scanning electronic microscope to show the inner and the outer surface and the cross section area of the pith bagasse and thermo gravimetric analyzer to investigate the degradation profile of the pith bagasse. The carbonized pith bagasse was packed into a polypropylene bag and its sorption behavior was studied. A comparison was made between the prepared pad and the commercial sorbents show that the pad containing carbonized pith bagasse has higher sorption capacity in comparison to the commercial sorbents. The pad exhibited high oil retention ability and a high selectivity for the oils over the water. The pad showed a possibility of reuse for eight times. The sorption capacity of the pads containing carbonized pith bagasse was found to increase with increasing the time of sorption till it reaches the maximum value at the time of sorption equal to 60 min. 相似文献
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This paper outlines a methodology to estimate monthly precipitation surfaces at 1-km resolution for the Upper Shiyang River watershed(USRW) in northwest China.Generation of precipitation maps is based on the application of a four-variable genetic algorithm(GA) trained on 10 years of weather and ancillary data,i.e.,surface air temperature,relative humidity,Digital Elevation Model-derived estimates of elevation,and time of year collected at 29 weather stations in west-central Gansu and northern Qinghai provin... 相似文献
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Numerous time-consuming equations, based on the relationship between the reliability and representativeness of the data utilized in defining variables and constants, require complex parameters to estimate bedload transport. In this study the easily accessible data including flow discharge, water depth, water surface slope, and surface grain diameter （ds0） from small rivers in Malaysia were used to estimate bedload transport. Genetic programming （GP） and artificial neural network （ANN） models are applied as complementary tools to estimate bed load transport based on a balance between simplicity and accuracy in small rivers. The developed models demonstrate higher performance with an overall accuracy of 97% and 93% for ANN and GP, respectively compared with other traditional methods and empirical equations. 相似文献
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Sawsan M. Ali Balsam S. Al-Tawash Khaldoun S. Al-Bassam 《Arabian Journal of Geosciences》2014,7(5):1811-1827
Baghdad City is characterized by high population density and wide variation in land use. It is covered by Quaternary flood plain deposits of variable nature where silt is the predominant component. The shallow aquifer is unconfined to semi-confined at some locations. The hydraulic properties of the aquifer are highly variable in the study area. A study of this groundwater shallow aquifer and the hydrochemical relation with the Tigris River were conducted using geochemical modeling approach. Baghdad Meteoric Water Line (BMWL) was also constructed using data of stable isotopes of hydrogen and oxygen. The hydrochemical parameters of the Tigris River show significant differences at high and low flow conditions, and there are clear difference among the selected stations. Groundwater parameters show also significant spatial and temporal variations in major and minor elements concentrations. Geochemical modeling results indicate that dissolution of dolomite, gypsum, chlorite, siderite, chalcedony, cation exchange of Ca2+/Na+ and precipitation of calcite, illite, kaolinite, and hematite are the main chemical reactions in the Rasafa side, whereas no specific reactions can be shown in the Karkh side. Mixing models of the shallow groundwater and Tigris River water show various patterns affected by other factors such as the aquifer recharge and evaporation, especially at the most shallow parts. The BMWL has been defined by the equation $ {\delta^2}\mathrm{H} = 8.6\ {\delta^{18}}\mathrm{O} + 17.48 $ and the stable isotopes of hydrogen and oxygen reveal different signatures in the Karkh and Rasafa sides, where clear zonation at Rasafa can be observed. We conclude that recharge water undergoes significant evaporation through its transit to the aquifer. 相似文献
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CASTRO ANTONIO; GUILLERMO CORRETGE L.; EL-BIAD MOHAMMED; EL-HMIDI HASSAN; FERNANDEZ CARLOS; PATINO DOUCE ALBERTO E. 《Journal of Petrology》2000,41(10):1471-1488
We have studied experimentally the melting relationships ofthe Ollo de Sapo gneiss (OSG), an important crustal protolithfor the Iberian leucogranites, of possible volcanoclastic origin.The results of this study are compared with previously determinedPTt paths, allowing us to interpret the mechanisms of meltingand granitoid production during the Hercynian orogenic cycle.Phase relationships determined in fluid-absent experiments indicatethat the OSG is a fertile source for peraluminous leucogranites.The slope of the fluid-absent solidus is strongly controlledby the breakdown of Ms in the presence of Qtz, Pl and Kfs. Thissolidus curve has a positive slope ranging from dP/dT = 30 bar/°Cat low P (<6 kbar) to dP/dT = 70 bar/°C at higher P (6–15kbar). The relationships between the Ms vapour-absent solidusand the PTt metamorphic paths in different sectors of the Iberianmassif have two important implications: (1) melt productivityis strongly favoured at low P; (2) anatexis in the Iberian massifprobably took place by decompression associated with crustalthinning and extension. These results are in agreement withthe relationships between granite production and tectonic deformationphases observed in the Iberian massif. Our results emphasizethat anatexis is a process that is strongly controlled bothby the phase relationships of the crustal protoliths and bythe thermal structure of the continental crust. Consequently,one must be careful when assigning potential crustal protolithsto particular granite associations exclusively on the basisof geochemical comparisons. KEY WORDS: anatexis; Hercynian orogen; Iberian massif 相似文献
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Muhammad Islam Abdul Razzaq Shamim Gul Sarfraz Ahmad Taj Muhammad Sawsan Hassan Barbara Rischkowsky M. N. M. Ibrahim Mounir Louhaichi 《山地科学学报》2018,15(4):685-694
Controlled grazing is considered a good management strategy to maintain or increase the live weight of livestock and to reduce vegetation degradation of rangelands. The present study investigated soil characteristics, aboveground vegetation biomass dynamics and controlled grazinginduced changes in the live weight of local ewes in the semi-arid rangeland of Ahmadun, Ziarat, Balochistan province of Pakistan. An area of 115 ha was protected from livestock grazing in April 2014. In June 2015, soil characteristics within 0-30 cm depth i.e. soil organic matter (SOM), mineral nitrogen, pH and texture in controlled and uncontrolled grazing sites were assessed. Aboveground vegetation biomass measured in early (June) and late summer (August) in 2015 and 2016. The nutritional value i.e. crude protein, phosphorus (P), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), magnesium (Mg) and potassium (K) of dominant plant species were assessed at the beginning of experiment in 2015. Vegetation cover of controlled and uncontrolled grazing sites was also measured during the two years of the study period using the VegMeasure software. From June to November in 2015 and 2016, controlled and uncontrolled livestock grazing sites were grazed on a daily basis by local ewes with a stocking rate of 2 and 1 head ha-1 respectively. Results reveal that the organic matter contents of coarse-textured, slightly alkaline soil of the study site were in the range of 9.4 - 17.6 g kg-1 soil and showed a strong positive correlation with aboveground vegetation biomass. The biomass of plants was 56.5% and 33% greater at controlled than uncontrolled grazing site in 2015 and 2016 respectively and plant cover was also higher at controlled than uncontrolled grazing site in both years. The nutrient contents were significantly (P<0.05) lower in grasses than shrubs. In both years, the controlled grazing increased the weight gain of ewes about two folds compared to the uncontrolled grazing. The results indicate that controlled grazing improved the vegetation biomass production and small ruminant productivity. 相似文献
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Three-dimensional(3 D)static modelling techniques are applied to the characterization of the Qishn Formation(Fm.)in the Sharyoof oil field locating within the Masila basin,southeastern Yemen.The present study was initiated by the seismic structural interpretation,followed by building a 3 D structural framework,in addition to analysing well log data and from these,3 D facies and petrophysical models are constructed.In the Sharyoof oil field,the Qishn Fm.exhibits depth values within the range of 400-780 m below sea level,with a general increase towards the SSE.A set of high dip angle normal faults with a general ENE-WSW trend dissect the rocks.The strata are also folded as a main anticline with an axis that is parallel to the fault trend,formed as a result of basement uplift.According to the facies models,the Qishn Fm.comprises 43.83% limestone,21.53% shale,21.26% sandstone,13.21% siltstone and 0.17% dolomite.The Qishn Carbonates Member has low porosity values making it a potential seal for the underlying reservoirs whereas the Upper Qishn Clastics SI A and C have good reservoir quality and SIB has fair reservoir quality.The Upper Qishn Clastics S2 and S3 also have fair reservoir quality,while the Lower Qishn Clastics zone has good reservoir quality.The water saturation decreases towards the west and east and increases towards north and south.The total original oil in-place(OOIP)of the Upper Qishn clastics is 106 million STB within the SI A,SIC and S2 zones.Drilling of development wells is recommended in the eastern study area,where good trapping configuration is exhibited in addition to the presence of a potential seal(Upper Qishn Carbonates Member)and reservoir(Qishn Clastics Member)with high porosity and low water saturation. 相似文献
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Magnitude and frequency of bedload transport was examined in the Lainbach River, Bavaria, using magnetically tagged particles. During the study, 18 small to moderate events and one major event occurred. About 1 per cent of the flow period exceeded the entrainment threshold and at least once every year about 50 per cent of the tagged particles were mobile. Themajor event which occurred during the study period resulted in the deposition of a thick layer of sediment in parts of the channel and passive burial of most of the recovered particles. The step–pool pattern, which characterized the study site prior to the large event, was obliterated. However, the channel recovered quickly and has returned to a new step–pool pattern. The event changed the boundary conditions by increasing the availability of loose sediment and creating higher river-bed slopes in reaches between breached check dams. As a result, movement of individual particles measured for events of both the same magnitude and duration, occurring before and after the large event, yielded different values. For events which occurred after the large event, the range and the mean distance of movement were about ten times higher. 相似文献