Effects of urbanization on river morphology of the Talar River,Mazandarn Province,Iran     

Saleh Yousefi  Hamid Reza Moradi  Saskia Keesstra  Hamid Reza Pourghasemi  Oldrich Navratil  Janet Hooke 《国际地球制图》2019,34(3):276-292

In the present study, we investigate the effects of urbanization growth on river morphology in the downstream part of Talar River, east of Mazandaran Province, Iran. Morphological and morphometric parameters in 10 equal sub-reaches were defined along a 11.5 km reach of the Talar River after land cover maps were produced for 1955, 1968, 1994, 2005 and 2013. Land cover types changed extremely during the study period. Residential lands were found to have increased in area by about 1631%, while forest land and riparian vegetation decreased in by approximately 99.9 and 96.2%, respectively. The results of morphometric and morphological factors showed that average channel width (W) for all 11.5 km of the study river decreased by 84% during the study period, while the flow length increased by about 2.14%.  相似文献   

GIS-based sustainable city compactness assessment using integration of MCDM,Bayes theorem and RADAR technology   总被引：1，自引：0，他引：1  

Saleh Abdullahi  Mustafa Neamah Jebur 《国际地球制图》2015,30(4):365-387

In recent decades, compact urban development and smart cities are recognised as most sustainable urban form in an effort to protect natural environment. Therefore, evaluation of existing compactness and sustainability of an area is an essential task before the real development takes place. In the literature, it is possible to see some studies on city’s compactness assessment and most of them have considered only a few aspects of compact development analysis. This paper aims to analyse urban sustainability of Kajang city (Malaysia) through a comprehensive city compactness assessment using geographical information system and radar remote sensing technology. To measure building density, a RADAR image of the study area was used to extract built-up areas with the aid of pixel-based and object-based classification schemes. Mixed land use development, urban density and intensity were the main indicators of the analysis. Finally, multicriteria decision-making and Bayes theorems were applied for overall compactness assessment. Building density analysis was validated using standard confusion matrix, which showed more than 90% accuracy. Similarly, the root-mean squared error showed 0.35 for object-based classification. The results classified the zones of the Kajang city in the range of least to most compact zones with the compactness value of 0.00273–0.0146, respectively. The results obtained in this study can help local government to improve the compactness of least compact zones to make Kajang city more sustainable. Furthermore, the results revealed that efficient public transportation and proper community facilities are the key factors to achieve sustainable urban development.  相似文献   

Changes in irrigation water consumption in the Nile Delta of Egypt assessed by remote sensing   总被引：1，自引：0，他引：1  

Mohammed A. El-Shirbeny  Magdy A. M. Alsersy  Nasser H. Saleh  Khaled A. Abu-Taleb 《Arabian Journal of Geosciences》2015,8(12):10509-10519

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Numerical study on the effects of floodplain vegetation on river planform style     

Alessandra Crosato  May Samir Saleh 《地球表面变化过程与地形》2011,36(6):711-720

The effects of floodplain vegetation on river planform have been investigated for a medium‐sized river using a 2D morphodynamic model with submodels for flow resistance and plant colonization. The flow resistance was divided into a resistance exerted by the soil and a resistance exerted by the plants. In this way it was possible to reproduce both the decrease in bed shear stress, reducing the sediment transport capacity of the flow within the plants, and the increase in hydraulic resistance, reducing the flow velocities. Colonization by plants was obtained by instantaneously assigning vegetation to the areas that became dry at low water stages. This colonization presents a step forward in the modelling of bank accretion. Bank erosion was related to bed degradation at adjacent wet cells. Bank advance and retreat were reproduced as drying and wetting of the computational cells at the channel margins. The model was applied to a hypothetical case with the same characteristics as the Allier River (France). The river was allowed to develop its own geometry starting from a straight, uniform, channel. Different vegetation densities produced different planforms. With bare floodplains, the river always developed a braided planform, even if the discharge was constant and below bankfull. With the highest vegetation density (grass) the flow concentrated in a single channel and formed incipient meanders. Lower vegetation density (pioneer vegetation) led to a transitional planform, with a low degree of braiding and distinguishable incipient meanders. The results comply with flume experiments and field observations reported in the literature.  相似文献   

Using multivariate statistical analyses to evaluate groundwater contamination in the northwestern part of Saudi Arabia   总被引：2，自引：1，他引：1  

Taisser Zumlot  Awni Batayneh  Yousef Nazal  Habes Ghrefat  Saad Mogren  Haider Zaman  Eslam Elawadi  Abdalaziz Laboun  Saleh Qaisy 《Environmental Earth Sciences》2013,70(7):3277-3287

Chemical characteristics of groundwater in the Midyan Basin (northwestern Saudi Arabia) were investigated and evaluated. A total of 72 water samples were collected from existing shallow wells and analyzed for different elements. Two multivariate statistical methods, hierarchical cluster analysis (HCA) and principal components analysis (PCA), were applied to a subgroup of the data set in terms of their usefulness for groundwater classification, and to identify the processes controlling groundwater geochemistry. The subgroup consisted of 46 water samples out of 72 samples and 24 variables included major elements (Ca²⁺, Na⁺, Mg²⁺, K⁺, Cl^?, HCO₃ ^?, NO₃ ^?, SO₄ ^2?), minor and trace element (SiO₂, Al, As, B, Ba, Cd, Cr, F, Fe, Mo, P, Pb, Sb, Sn, Ti, and V). For water samples, four geochemically distinct clusters (i.e., C1, C2, C3 and C4) have been observed by hierarchical cluster analysis. Cr, F and Pb are the dominant ions in cluster C2. Al, As, Cd, Mo, Sb and Ti are the dominant ions in cluster C3, while B, Ca, Cl, HCO₃, K, Mg, Na, SO₄ and V are identified as dominant ions in the cluster C4. In the PCA, a total of five components are extracted form the data set, which explained 73.37 % of the total data variability. Among them the first component reveals strong associations between As, B, Cd, Cr, F, Mo, Pb, Sb and Ti. The second component reveals the associations between Ca, Cl, HCO₃, Mg, Na, SO₄ and V.  相似文献   

Assessment of land degradation east of the Nile Delta, Egypt using remote sensing and GIS techniques   总被引：1，自引：0，他引：1  

E. S. Mohamed  A. Belal  A. Saleh 《Arabian Journal of Geosciences》2013,6(8):2843-2853

Land degradation is one of the most common issues in the eastern part of the Nile Delta area that threatens the ongoing agricultural activities and prohibits further reclamation expansions. The different degradation types and the associated risk assessment of some soils types of western Suez Canal region during the period from 1997 to 2010 is discussed. The assessment of the different degradation degrees in the investigated area has been carried out through integrating remote sensing, GIS and GLASOD approaches. Results revealed that the salinization, alkalization, soil compaction and water logging are the main types of land degradation in the area. The main causative factors of human induced land degradation types are; over irrigation, human intervention in natural drainage, improper time use of heavy machinery and the absence of conservation measurements. Low and moderately clay flats, gypsifferous flats, have high to very high risk in both salinization sodication and physical degradation. Values such as EC, ESP, and ground water level reach 104.0 dS/m, 176? % and 60 cm, respectively. These results will be of great help and be basic sources for the planners and decision makers in sustainable planning. The spatial land degradation model was developed based on integration between remote sensing data, geographic information system, soil characteristics and DEM.  相似文献   

Recent crustal deformation and seismicity studies at Abu-Dabbab area, Red Sea, Egypt     

Abdel-Monem S. Mohamed  M. Saleh  S. Mahmoud  A. Teleab  A. A. Othman  Diaa Hamed 《Arabian Journal of Geosciences》2013,6(4):1283-1293

The Abu-Dabbab area is characterized by high seismicity and complex tectonic setting; for these facts, a local geodetic network consisting of 11 geodetic benchmarks has been established. The crustal deformation data in this area are collected using the GPS techniques. Five campaigns of GPS measurements have been collected, processed, and adjusted to get the more accurate positions of the GPS stations. The horizontal velocity vectors, the dilatational, the maximum shear strains, and the principal strain rates were estimated. The horizontal velocity varies in average between 3 and 6 mm per year across the network. The results of the deformation analysis indicate a significant contraction and extension across the southern central part of the study area which is characterized by high seismic activity represented by the clustering shape of the microearthquakes that trending ENE. The north and northeastern parts are characterized by small strain rates. This study is an attempt to provide valuable information about the present state of the crustal deformation and its relationship to seismic activity and tectonic setting at the Abu-Dabbab area. The present study is the first work demonstrating crustal deformation monitoring at the Abu-Dabbab area. The time interval is relatively short. Actually, these results are preliminary results. So, the continuity of GPS measurements is needed for providing more information about the recent crustal deformation in that area.  相似文献   

Estimating Curie Point Depth and Heat Flow Map for Northern Red Sea Rift of Egypt and Its Surroundings, from Aeromagnetic Data     

Salah Saleh  Müjgan Salk  Oya Pamukçu 《Pure and Applied Geophysics》2013,170(5):863-885

In this study, we aim to map the Curie point depth surface for the northern Red Sea rift region and its surroundings based on the spectral analysis of aeromagnetic data. Spectral analysis technique was used to estimate the boundaries (top and bottom) of the magnetized crust. The Curie point depth (CPD) estimates of the Red Sea rift from 112 overlapping blocks vary from 5 to 20 km. The depths obtained for the bottom of the magnetized crust are assumed to correspond to Curie point depths where the magnetic layer loses its magnetization. Intermediate to deep Curie point depth anomalies (10–16 km) were observed in southern and central Sinai and the Gulf of Suez (intermediate heat flow) due to the uplifted basement rocks. The shallowest CPD of 5 km (associated with very high heat flow, ~235 mW m^?2) is located at/around the axial trough of the Red Sea rift region especially at Brothers Island and Conrad Deep due to its association with both the concentration of rifting to the axial depression and the magmatic activity, whereas, beneath the Gulf of Aqaba, three Curie point depth anomalies belonging to three major basins vary from 10 km in the north to about 14 km in the south (with a mean heat flow of about 85 mW m^?2). Moreover, low CPD anomalies (high heat flow) were also observed beneath some localities in the northern part of the Gulf of Suez at Hammam Fraun, at Esna city along River Nile, at west Ras Gharib in the eastern desert and at Safaga along the western shore line of the Red Sea rift. These resulted from deviatoric tensional stresses developing in the lithosphere which contribute to its further extension and may be due to the opening of the Gulf of Suez and/or the Red Sea rift. Furthermore, low CPD (with high heat flow anomaly) was observed in the eastern border of the study area, beneath northern Arabia, due to the quasi-vertical low-velocity anomaly which extends into the lower mantle and may be related to volcanism in northern Arabia. Dense microearthquakes seem to occur in areas where the lateral gradients of the CPD are steep (e.g. entrance of the Gulf of Suez and Brothers Island in the Red Sea). These areas may correspond to the boundaries between high and low thermal regions of the crust. Thus, the variations in the microseismic activity may be closely related to thermal structures of the crust. Indeed, shallow cutoff depths of seismicity can also be found in some geothermal areas (e.g. western area of Safaga city along the Red Sea coastal region and at Esna city along the River Nile). These facts indicate that the changes in the thickness of the seismogenic layer strongly depend on temperature. Generally, the shallow Curie point depth indicates that some regions in our study area are promising regions for further geothermal exploration particularly in some localities along the River Nile, Red Sea and Gulf of Suez coastal regions.  相似文献   

Geochemical characteristics and spectrometric prospecting in the muscovite-bearing pegmatites and granites,southeastern Aswan,Egypt     

Gehad M. Saleh Mohamed M. ElGaly Mohamed A. Obeid 《中国地球化学学报》2008,27(1):9-20

Rare metal mineralization of Sn, Nb-Ta and W is encountered in the Gebel Dihmit area （GDA）, southeastern Aswan, Egypt. The mineralization is related to muscovite granites and their pegmatite derivatives. The pegmatites are divided into three types according to their main mineral assemblages： K-feldspar-muscovite-tourmaline, K-feldspar-albite-muscovite and albite-K-feldspar-lepidolite veins. Petrogenetic studies indicate that Sn and Nb-Ta mineralization extends from the late-magmatic stage to the pegmatite and hydrothermal stages of the （GDA） suite. The albite-K-feldspar-lepidolite granite is composed dominantly of albite, lepidolote, and quartz, with topaz, K-feldspar and amblygonite. The accessory minerals are zircon, monazite, pollucite, columbite-tantalite, microlite and Ta-rich cassiterite. Phenocrysts of quartz, topaz and K-feldspar contain abundant inclusions of albite laths and occasional lepidolite crystals along growth zones （snowball texture）, indicating simultaneous crystallization from a subsolvus, residual magma. The origin of the pegmatites is attributed to extreme differentiation by fractional crystallization of a granitic magma. The economic potential for rare metals was evaluated in the geochemical discrimination diagrams. Accordingly, some of the pegmatites are not only highly differentiated in terms of alkalis, but also the promising targets for small-scale Ta and, to a less extent, Sn. The pegmatites also provide the first example of Fe-Mn and Nb-Ta fractionation in successive generations of granites to cassiterite-bearing pegmatites, which perfectly ex- hibit similar fractionation trends established for primary columbite-tantalite in the corresponding categories of pegmatites. Uranium and Th of magmatic origin are indicated by the presence of thorite and allanite, whereas evidence of hydrothermal mineralization is the alteration of rock- foring minerals such as feldspar and the formation of secondary minerals such as uranophane..  相似文献   

Geochemistry and spectrometric prospection of younger granites and granitic pegmatites bearing uranium mineralization at G. Kab El Rakeb area,Central Eastern Desert,Egypt     

Saleh  Gehad M.  Emad  Bahaa M.  Abdel Kader  Ibrahim B. 《中国地球化学学报》2021,40(4):575-601

Acta Geochimica - The present study deals with the detailed field geology, mineralogy, geochemistry, and spectrometric prospection of rare metals and radioactive minerals associated with granitic...  相似文献