Environmental contamination of Zn,Cd, Ni,Cu, and Pb from industrial areas in Hamadan Province,western Iran     

M. Jalali  Z. V. Khanlari 《Environmental Geology》2008,55(7):1537-1543

Eleven surface soil samples from calcareous soils of industrial areas in Hamadan Province, western Iran were analyzed for total concentrations of Zn, Cd, Ni, Cu and Pb and were sequentially extracted into six fractions to determine the bioavailability of various heavy metal forms. Total Zn, Cd, Ni, Cu and Pb concentrations of the contaminated soils were 658 (57–5,803), 125.8 (1.18–1,361), 45.6 (30.7–64.4), 29.7 (11.7–83.5) and 2,419 (66–24,850) mg kg⁻¹, respectively. The soils were polluted with Zn, Pb, and Cu to some extent and heavily polluted with Cd. Nickel values were not above regulatory limits. Copper existed in soil mainly in residual (RES) and organic (OM) fractions (about 42 and 33%, respectively), whereas Zn occurred essentially as RES fraction (about 69%). The considerable presence of Cd (30.8%) and Pb (39%) in the CARB fraction suggests these elements have high potential biavailability and leachability in soils from contaminated soils. The mobile and bioavailable (EXCH and CARB) fractions of Zn, Cd, Ni, Cu, and Pb in contaminated soils averaged (7.3, 40.4, 16, 12.9 and 40.8%), respectively, which suggests that the mobility and bioavailability of the five metals probably decline in the following order: Cd = Pb > Ni > Cu > Zn.  相似文献   

Efficiency analysis of open trench for impact pile driving through a single-variable method     

Amir Hamidi  Abtin Farshi Homayoun Rooz 《Marine Georesources & Geotechnology》2021,39(1):82-102

Abstract

The ground vibrations during pile driving operation have a drastic potential to undermine the surrounding structures both in land and reclaimed land. Particularly, reclaimed land necessitates ample application of pile driving due to the weak land condition. To prevent the structural damage, attenuation of the ground vibrations to an allowable level through active isolation of circular open trench is the scope of this study. In this research, finite element simulations of continuous impact pile driving process from the ground surface was executed with particular attention to the pile-soil interaction, and thereby, the efficiency of open trench application in attenuation of the unsafe distance of different structures was surveyed using the vibration sensitivity degree. Regarding the crucial parameters of an open trench (depth, width, and location), it was concluded that a sufficient high depth can attenuate the unsafe distance up to 68%, the trench width variations are less effective, and an average pile-trench distance is the most efficient option. The excavation volume was also concluded as another crucial parameter in open trench design which takes all three parameters into account. The trench depth equal to the pile’s maximum critical depth of vibration was inferred for an optimum design.  相似文献   

Chemical characteristics of groundwater in parts of mountainous region, Alvand, Hamadan, Iran   总被引：5，自引：0，他引：5  

Mohsen Jalali 《Environmental Geology》2006,51(3):433-446

Eighty-seven groundwater samples have been collected from a mountainous region (Alvand, Iran) for hydrochemical investigations to understand the sources of dissolved ions and assess the chemical quality of the groundwater. Most water quality parameters are within World Health Organization acceptable limits set for drinking water. The least mineralized water is found closest to the main recharge zones and the salinity of water increased towards the north of the basin. The most prevalent water type is Ca–HCO₃ followed by water types Ca–NO₃, Ca–Cl, Ca–SO₄ and Mg–HCO₃. The Ca–NO₃ water type is associated with high nitrate pollution. Agricultural and industrial activities were associated with elevated level of NO₃⁻. Mineral dissolution/weathering of evaporites dominates the major element hydrochemistry of the area. Chemical properties of groundwater in Alvand region are controlled both by natural geochemical processes and anthropogenic activities.  相似文献   

Context Aware Modification on the Object Based Image Analysis     

Fatemeh Tabib Mahmoudi  Farhad Samadzadegan  Peter Reinartz 《Journal of the Indian Society of Remote Sensing》2015,43(4):709-717

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A multi-dimensional assessment of urban vulnerability to climate change in Sub-Saharan Africa     

Lise Byskov Herslund  Fatemeh Jalayer  Nathalie Jean-Baptiste  Gertrud Jørgensen  Sigrun Kabisch  Wilbard Kombe  Sarah Lindley  Patrik Karlsson Nyed  Stephan Pauleit  Andreas Printz  Trond Vedeld 《Natural Hazards》2016,82(2):149-172

In this paper, we develop and apply a multi-dimensional vulnerability assessment framework for understanding the impacts of climate change-induced hazards in Sub-Saharan African cities. The research was carried out within the European/African FP7 project CLimate change and Urban Vulnerability in Africa, which investigated climate change-induced risks, assessed vulnerability and proposed policy initiatives in five African cities. Dar es Salaam (Tanzania) was used as a main case with a particular focus on urban flooding. The multi-dimensional assessment covered the physical, institutional, attitudinal and asset factors influencing urban vulnerability. Multiple methods were applied to cover the full range of vulnerabilities and to identify potential response strategies, including: model-based forecasts, spatial analyses, document studies, interviews and stakeholder workshops. We demonstrate the potential of the approach to assessing several dimensions of vulnerability and illustrate the complexity of urban vulnerability at different scales: households (e.g., lacking assets); communities (e.g., situated in low-lying areas, lacking urban services and green areas); and entire cities (e.g., facing encroachment on green and flood-prone land). Scenario modeling suggests that vulnerability will continue to increase strongly due to the expected loss of agricultural land at the urban fringes and loss of green space within the city. However, weak institutional commitment and capacity limit the potential for strategic coordination and action. To better adapt to urban flooding and thereby reduce vulnerability and build resilience, we suggest working across dimensions and scales, integrating climate change issues in city-level plans and strategies and enabling local actions to initiate a ‘learning-by-doing’ process of adaptation.  相似文献   

Numerical simulation of groundwater flow and aquifer-system compaction using simulation and InSAR technique: Saveh basin,Iran     

Fatemeh Jafari  Saman Javadi  Golmar Golmohammadi  Neamat Karimi  Koroush Mohammadi 《Environmental Earth Sciences》2016,75(9):833

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Long-term seasonal rainfall forecasting: efficiency of linear modelling technique     

Iqbal Hossain  H. M. Rasel  Monzur Alam Imteaz  Fatemeh Mekanik 《Environmental Earth Sciences》2018,77(7):280

Using the lagged (past) climate indices, including El Nino–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) as input parameters and long-term spring rainfall as outputs, calibration and validation of the linear multiple regression (MR) models have been performed. Since Australian rainfall varies both temporally and spatially, the analysis on the linear MR models was performed on regional scale. These models show the capability of linear MR technique for long-term predictions of Western Australian spring rainfall. The emphasis was given to assess the statistical correlations between Western Australian spring rainfall and dominating large-scale climate modes. The efficiency of linear modelling technique was evaluated to predict seasonal rainfall forecasting. At the same time, the Pearson correlation (R), mean absolute error, root-mean-square error and Willmott index agreement (d) were used to assess the capability of MR models. The models which fulfilled the limits of statistical significances were used for the prediction of future spring rainfall using independent data set. The results indicate that during calibration periods maximum achievable correlations varied from 0.47 to 0.53 for the selected stations. In regard to predict peaks and troughs of rainfall time series, it was found that correlations between predicted and actual peaks varied from 0.82 to 0.94 and between predicted and actual troughs varied from 0.53 to 0.91.  相似文献   

Chemical composition of rock-forming minerals and crystallization physicochemical conditions of the Middle Eocene I-type Haji Abad pluton,SW Buin-Zahra,Iran     

Kazem Kazemi  Ali Kananian  Yilin Xiao  Fatemeh Sarjoughian 《Arabian Journal of Geosciences》2018,11(22):717

The Haji Abad intrusion is a well-exposed Middle Eocene I-type granodioritc pluton in the Urumieh–Dokhtar magmatic assemblage (UDMA). The major constituents of the investigated rocks are K-feldspar, quartz, plagioclase, pyroxene, and minor Fe–Ti oxide and hornblende. The plagioclase compositions fall in the labradorite, andesine, and oligoclase fields. The amphiboles range in composition from magnesio-hornblende to tremolite–hornblende of the calcic-amphibole group. Most pyroxenes principally plot in the field of diopside. The calculated average pressure of emplacement is 1.9 kbar for the granodioritic rocks, crystallizing at depths of about 6.7 km. The highest pressure estimated from clinopyroxene geobarometry (5 kbar) reflects initial pyroxene crystallization pressure, indicating initial crystallization depth (17.5 km) in the Haji Abad granodiorite. The estimated temperatures using two-feldspar thermometry give an average 724 °C. The calculated average temperature for clinopyroxene crystallization is 1090 °C. The pyroxene temperatures are higher than the estimated temperature by feldspar thermometry, indicating that the pyroxene and feldspar temperatures represent the first and late stages of magmatic crystallization of Haji Abad granodiorite, respectively. Most pyroxenes plot above the line of Fe³⁺?=?0, indicating they crystallized under relatively high oxygen fugacity or oxidized conditions. Furthermore, the results show that the Middle Eocene granitoids crystallized from magmas with H₂O content about 3.2 wt%. The relatively high water content is consistent with the generation environment of HAG rocks in an active continental margin and has allowed the magma to reach shallower crustal levels. The MMEs with ellipsoidal and spherical shapes show igneous microgranular textures and chilled margins, probably indicating the presence of magma mixing. Besides, core to rim compositional oscillations (An and FeO) for the plagioclase crystals serve as robust evidence to support magma mixing. The studied amphiboles and pyroxenes are grouped in the subalkaline fields that are consistent with crystallization from I-type calc-alkaine magma in the subduction environment related to active continental margin. Mineral chemistry data indicate that Haji Abad granodiorites were generated in an orogenic belt related to the volcanic arc setting consistent with the subduction of Neo-Tethyan oceanic crust beneath the central Iranian microcontinent.  相似文献   

The interaction of two asymmetric quasi-geostrophic vortex patches     

M. M. Jalali 《地球物理与天体物理流体动力学》2013,107(6):375-401

ABSTRACT

Herein we study the general interaction of two vortex patches in a single-layer quasi-geostrophic shallow-water flow. Steadily-rotating equilibrium states are found over a wide parameter space spanning the Rossby deformation length, vortex area ratio, potential vorticity ratio, and gap between their innermost edges. A linear stability analysis is then used to identify the critical gap separating stable and unstable solutions, over the entire range of area and potential vorticity ratios, and for selected values of the Rossby deformation length. A representative set of marginally unstable equilibrium states are then slightly perturbed and evolved by an accurate contour dynamics numerical algorithm to understand the long-term fate of the instabilities. Not all instabilities lead to vortex merger; many in fact are characterised by weak filamentation and a small adjustment of the vortex shapes, without merger. Stronger instabilities lead to material being torn from one vortex and either wrapped around the other or reduced to ever thinning filamentary debris. A portion of the vortex may survive, or it may be completely strained out by the other.  相似文献   

Unconfined Compression Strength of Polymer Stabilized Forest Soil Clay     

Mousavi  Fatemeh  Abdi  Ehsan 《Geotechnical and Geological Engineering》2022,40(8):4095-4107

Geotechnical and Geological Engineering - Due to undesired mechanical characteristics, some forest soils cause problems in road construction. Several methods have been proposed for stabilizing...  相似文献