A dye-tracing test as an aid to studying karst development at an artesian limestone sub-aquifer: Zagros Zone,Iran     

Zargham Mohammadi  Ezzatollah Raeisi  Mohammad Zare 《Environmental Geology》2007,52(3):587-594

A dye-tracing test is employed to study the karst development and flow regime at an artesian limestone sub-aquifer, the Khersan3 Dam site, Zagros Zone, Iran. Tracer breakthrough curves showed an early dominant peak followed by a pronounced tailing effect. The peak concentration was a response to induced pressure during dye injection. The results suggest that the dye was pushed into the small pores and fissures around the injection point during dye injection. Hence, the dye moved out as a result of matrix and fissure diffusive processes and created a long pronounced tailing. The maximum flow velocity in the upper artesian sub-aquifer ranged from 0.97 to 2.9 m/h. However, the mean tracer velocity ranged from 0.19 to 0.51 m/h based on the mean residence tracer time; consequently, the flow regime in the artesian sub-aquifer was determined to be mainly diffusive. The results reveal (1) a low hydraulic gradient from upstream of the dam axis to downstream; consequently, there is no considerable flow; (2) poor karst development and diffuse flow at the tracing test area; (3) a discharge zone at a location downstream of the dam axis which is the main terminal of general flow direction at the dam site.  相似文献   

Regional analysis of streamflow drought: a case study in southwestern Iran     

Motalleb Byzedi  Bahram Saghafian  Khosro Mohammadi  Maaroof Siosemarde 《Environmental Earth Sciences》2014,71(6):2955-2972

Droughts are complex natural hazards that, to a varying degree, affect some parts of the world every year. The range of drought impacts is related to drought occurring in different stages of the hydrological cycle and usually different types of droughts such as meteorological, agricultural, hydrological, and socio-economical are the most distinguished types. Hydrological drought includes streamflow and groundwater droughts. In this paper, streamflow drought was analyzed using the method of truncation level (at 70 % level) by daily discharges at 54 stations in southwestern Iran. Frequency analysis was carried out for annual maximum series of drought deficit volume and duration. 35 factors such as physiographic, climatic, geologic and vegetation were studied to carry out the regional analysis. According to conclusions of factor analysis, the six most effective factors include watershed area, the sum rain from December to February, the percentage of area with NDVI <0.1, the percentage of convex area, drainage density and the minimum of watershed elevation, explained 89.2 % of variance. The homogenous regions were determined by cluster analysis and discriminate function analysis. The suitable multivariate regression models were ascertained and evaluated for hydrological drought deficit volume with 2 years return period. The significance level of models was 0.01. The conclusion showed that the watershed area is the most effective factor that has a high correlation with drought deficit volume. Moreover, drought duration was not a suitable index for regional analysis.  相似文献   

Mineralogical and geochemical studies on the Gowd-e-Morad (Ni,Co, As–Cu) mineral deposit,Anarak (central Iran)     

N. Mazaheri Kuhanestani  B. Mokhtarzadeh Mohammadi  D. H. M. Alderton  S. H. Tabatabaei  H. Bagheri 《Arabian Journal of Geosciences》2014,7(11):4779-4791

The Ni, Co, As, and Cu deposit of Gowd-e-Morad is located 20 km northwest of Anarak in Central Iran. In this hydrothermal deposit, mineralization occurs as veins in a fault breccia zone hosted by the Chahgorbeh (schist and metabasite) complex. The main ores are made up of Ni, Co, and Cu arsenides. Petrologic studies and results obtained from geochemical analyses have indicated that the Ni, Co, As, and Cu are derived from ultramafic rocks while Pb and Zn are likely to be derived from schist. Based on the geochemical evidence, particularly the high correlation between Ni, Co, and As, it is proposed that this deposit be categorized as a “five elements” mineral deposit. Fluid inclusion studies have shown homogenization temperatures (T_H) in the range 113?206 ?C and salinity 3?13.5 % wt eq. NaCl. Therefore this “five elements” mineral deposit has been determined as a low temperature, epithermal deposit type. It is proposed that the low fluid temperatures are a result of an environment of formation which was distal to a volcanogenic source systems and the major influence of meteoric waters in the hydrothermal system.  相似文献   

Metal-organic framework Uio-66 for adsorption of methylene blue dye from aqueous solutions     

A. A. Mohammadi  A. Alinejad  B. Kamarehie  S. Javan  A. Ghaderpoury  M. Ahmadpour  M. Ghaderpoori 《International Journal of Environmental Science and Technology》2017,14(9):1959-1968

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Design,manufacture and calibration of the SARI portable rainfall simulator for field and laboratory experiments     

Ataollah Kavian  Maziar Mohammadi  Artemi Cerdà  Moghadaseh Fallah  Leila Gholami 《水文科学杂志》2019,64(3):350-360

The Simulator of Artificial RaInfall (SARI) rainfall simulator (RS) is a newly designed, constructed and calibrated, portable, two-nozzle RS with low water consumption, accurate measurement, easy management and low cost. The raindrop size distribution and velocity and mean rainfall intensity were measured. The best rainfall spatial distribution was achieved with nozzles separated by 50, 60 and 70 cm, and with oscillation angles of 30, 45 and 60°, at a pressure of 60 kPa. The uniformity coefficient varied from 57 to 61% and rainfall intensity from 48 to 101 mm h^?1. The raindrop diameter varied from 0.2 to 9.9 mm. The raindrop velocity at the optimum pressure of 60 kPa, which was measured with high-speed photography, ranged from 1.1 to 7.1 m s^?1. Comparison with other RSs shows that the SARI simulator is a suitable apparatus to research soil erosion and runoff generation under laboratory and field conditions.  相似文献   

Investigating extreme scenarios with multiple-point geostatistics and variance maximization     

Abdollahifard  Mohammad Javad  Mari&#;thoz  Gr&#;goire  Mohammadi  Hesam Soltan 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(1):67-85

Stochastic Environmental Research and Risk Assessment - In many geoscience applications, the data extracted from environmental variables are very limited. Multiple-point geostatistical (MPS)...  相似文献