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Detection of soil salinity changes and mapping land cover types based upon remotely sensed data 总被引：2，自引：1，他引：1
Hamid Reza Matinfar Sayed Kazem Alavi Panah Farhad Zand Kamal Khodaei 《Arabian Journal of Geosciences》2013,6(3):913-919
Soil salinity is a major environmental hazard. The global extent of primary and secondary salt affected soils is about 955 and 77 M?ha, respectively. Soil salinity tends to increase in spite of considerable effort dedicated to land reclamation. This requires careful monitoring of the soil salinity status. The objectives of this study were: (a) to evaluate the capability of thematic mapper (TM) and multispectral scanner (MSS) imagery for mapping land cover types, (b) to analyse the spectral features of sail crusts relative to bare soil and gravely soil surface conditions, and (c) to detect the soil salinity changes during the period 1975–2004 in the Ardakan area located in the central Iranian Deserts. The Landsat MSS and TM on two different dates of September 14, 1975 and September 11, 2004, respectively, were used. Due to great confusion between some classes, the TM 6 was included in the band combination. The result of the image classification based on the combination of TM bands 3, 4, 5, and 6 showed of the classification results. For multi-temporal analysis, both TM and MSS images were classified with the same method but with a different number of training classes. The TM-classified image was regrouped to make it comparable with MSS regrouped classified image. The comparison between the classified images showed about 39% of the total area had changed in 29 years. The result of this study revealed the possibility of detecting important soil salinity changes by using Landsat satellite data 相似文献
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Based on analyses of calcite twins, we constrain the tectonic history of the Paleozoic Sargaz complex within the SE part of the Sanandaj–Sirjan zone (hinterland domain of the Zagros orogen), SE Iran. The mean width of measured calcite twins was 1.97 μm, corresponding to the width of type II twins; variations in twin width with twin density indicate that calcite twinning in the study area occurred at temperatures of between 170 and 200°C. These results support the interpretation that the twins developed at a shallower depth and lower temperature than those of greenschist facies metamorphism recorded in this complex, and that twinning is therefore mainly a late, post-metamorphic deformation process. The c-axis fabrics of the studied samples are monoclinic, consisting of an intense point maximum located slightly anticlockwise of the normal to the shear plane; this asymmetry indicates non-coaxial deformation and a dextral component of shear in the thrust zones. The geometric relationship between stress axes and bedding reveals that the reconstructed stress tensors mainly post-date F1-folding. Compressional stress axes are oriented NE–SW. This compressional stress was probably related to the (oblique) subduction of the Neotethys beneath Central Iran by Middle Triassic–Jurassic times, during the Cimmerian orogeny. 相似文献
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Alavi Nezhad Khalil Abad S. V. Mohamad Edy Tonnizam Komoo Ibrahim Kalatehjari R. 《Arabian Journal of Geosciences》2015,8(4):2191-2201
Arabian Journal of Geosciences - One of the most important challenges in the study of slope stability, foundation, and excavation in rocks is understanding the weathering states. This issue is more... 相似文献
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M. Nameni M.Sc. M. R. Alavi Moghadam M. Arami 《International Journal of Environmental Science and Technology》2008,5(2):161-168
In this research, adsorption of chromium (VI) ions on wheat bran has been studied through using batch adsorption techniques. The main objectives of this study are to 1) investigate the chromium adsorption from aqueous solution by wheat bran, 2) study the influence of contact time, pH, adsorbent dose and initial chromium concentration on adsorption process performance and 3) determine appropriate adsorption isotherm and kinetics parameters of chromium (VI) adsorption on wheat bran. The results of this study showed that adsorption of chromium by wheat bran reached to equilibrium after 60 min and after that a little change of chromium removal efficiency was observed. Higher chromium adsorption was observed at lower pHs, and maximum chromium removal (87.8 %) obtained at pH of 2. The adsorption of chromium by wheat bran decreased at the higher initial chromium concentration and lower adsorbent doses. The obtained results showed that the adsorption of chromium (VI) by wheat bran follows Langmuir isotherm equation with a correlation coefficient equal to 0.997. In addition, the kinetics of the adsorption process follows the pseudo second-order kinetics model with a rate constant value of 0.131 g/mg.min The results indicate that wheat bran can be employed as a low cost alternative to commercial adsorbents in the removal of chromium (VI) from water and wastewater. 相似文献
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The virani ophiolite complex and surrounding rocks 总被引：1，自引：0，他引：1
Dr. Mehdi Alavi 《International Journal of Earth Sciences》1979,68(1):334-341
The Virani ophiolite complex consists of metamophosed ultramafics, mafics, and cherts, and forms an allochthonous sheet that structurally overlies a sequence of metamorphosed flysch-type deposits. The complex and structurally underlying metamorphosed sedimentary rocks have been affected by three phases of folding. The first and second phases of folding produced isoclinal folds with subparallel trends and nearly-horizontal axes which resulted in the apparent interlayered character of the rock units.
Zusammenfassung Der Virani-Ophiolith-Komplex besteht aus metamorphen Kieselschiefern neben ultramaphischen und maphischen Gesteinen. Sie liegen über einer Serie von metamorphen Flysch-Sedimenten. Dieser Komplex und die darunter liegenden Sedimente wurden von drei Faltungsphasen beeinflußt. Die erste und zweite Faltungsphase verursachten isoklinale Falten mit subparallelem Streichen und fast horizontalen Achsen.
Résumé Le complexe ophiolitique de Virani consiste en roches métamorphiques ultramafiques, mafiques et en cherts; il forme une couverture allochtone qui recouvre structuralement une série des couches métamorphiques de type flysch. Le complexe et les roches sédimentaires métamorphiques structuralement sous-jacentes ont été affectées par trois phases de plissement. La première et la deuxième phases de plissement ont produit des plis isoclinaux á axes presqu'horizontaux et d'allure subparallèle, qui ont eut pour résultat de donner aux unités lithologiques l'apparence d'intercalations.
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The mixtures of dried sewage sludge (DSS) and sewage sludge ash were studied for removal of acid red 119 (AR119) dye as a new, more environmental friendly, and low cost adsorbent. For this purpose, response surface methodology was applied to optimize the dye removal efficiency and turbidity of treated dye solutions as two individual responses. Results revealed that an optimum condition under specified constraints (dye removal efficiency >95% and turbidity <50 NTU) was obtained at a contact time of 60 min, 40 wt% DSS in the mixture, an initial pH of 6, and an initial dye concentration of 200 mg dye/L in distilled water. Under the optimal condition, dye removal efficiency of 94.98% and effluent turbidity of 24.9 NTU was observed. In further studies, at optimum condition, the effect of some additives on adsorption process and desorption/reusability of adsorbent was investigated. It was observed that removal efficiency was significantly decreased to 83.76% when a simulated dye wastewater (containing the selected dye, acetic acid, and Glauber's salt dissolved in tap water) was used. Desorption studies revealed that AR119 dye could be well removed from dye‐loaded adsorbent by 0.3 M NaOH solution. 相似文献
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Naghibi Seyed Amir Vafakhah Mehdi Hashemi Hossein Pradhan Biswajeet Alavi Seyed Jalil 《Natural Resources Research》2020,29(3):1915-1933
Natural Resources Research - Lack of water resources is a common issue in many countries, especially in the Middle East. Flood spreading project (FSP) is an artificial recharge technique, which is... 相似文献
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