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1.
Koohbanani Hamidreza Yazdani Mohammadreza Hosseini Sayyed Keivan 《Natural Hazards》2020,103(1):785-798
Natural Hazards - Due to excessive harvesting of underground water resources in many important aquifers inside Iran, ground subsidence is occurring at different speeds. In present study, InSAR... 相似文献
2.
Mojtaba Pakparvar Hossein Hashemi Meisam Rezaei Wim M. Cornelis Gholamali Nekooeian Sayyed Ahang Kowsar 《水文科学杂志》2018,63(8):1183-1202
To assess recharge through floodwater spreading, three wells, approx. 30 m deep, were dug in a 35-year-old basin in southern Iran. Hydraulic parameters of the layers were measured. One well was equipped with pre-calibrated time domain reflectometry (TDR) sensors. The soil moisture was measured continuously before and after events. Rainfall, ponding depth and the duration of the flooding events were also measured. Recharge was assessed by the soil water balance method, and by calibrated (inverse solution) HYDRUS-1D. The results show that the 15 wetting front was interrupted at a layer with fine soil accumulation over a coarse layer at the depth of approx. 4 m. This seemed to occur due to fingering flow. Estimation of recharge by the soil water balance and modelling approaches showed a downward water flux of 55 and 57% of impounded floodwater, respectively. 相似文献
3.
Comparative assessment of baseline concentration of the heavy metals in the soils of Tehran (Iran) with the comprisable reference data 总被引：1，自引：0，他引：1
Industrial soil systems have become complex due to human activities, as they disturb the natural development of soil and add
hazardous elements. Hence, there is a growing public concern over the accumulation of heavy metals in soil due to the rapid
industrial development during the last decade in Iran. The objectives of the present study are to carry out comparative assessment
of the heavy metals in soils of the Chitgar Industrial Area Tehran (Iran) with average world guidelines and to evaluate enrichment
and normalized scatter coefficient. In this work the concentrations of seven heavy metals (Cr, Co, Cd, Cu, Pb, Ni and Zn)
from the surface soils of the industrial area were quantified, based on 210 samples collected from 70 sampling stations in
three consecutive seasons May 2007, November 2007 and May 2008 using 0.5 × l Km square mesh. Common comparison methods were
employed to assess the quality of soils and guideline values were used to represent a desired level of elements. Comparison
variables and enrichment factor showed that Pb has high-level value while normalized scatter coefficient demonstrates that
Cd increases in soils more rapidly as compared to other elements. This study revealed that normalized scatter coefficient
can be effectively used to evaluate soil pollution and is independent of the past. 相似文献
4.
An intrabasaltic red bole horizon is studied for its weathering characteristics with respect to the underlying and overlying basalts. The study indicates that all the three units have been considerably weathered; the red bole unit, however shows some distinctive characteristics. The red boles show a higher cation exchange capacity (CEC) and lower sodium adsorption ratio (SAR) and organic carbon (OC) as compared to the weathered basalts. The lower values of Al2O3, TiO2 and Fe2O3(T) in red boles indicate their lesser weathering than the underlying and overlying basalts, which is further corroborated by the weathering intensity measured by the indices like chemical index of alteration (CIA) and statistical empirical index of chemical weathering (W). It is also evident that the red bole samples show more retention of original mafic and felsic components. While K2O exhibits an erratic behaviour, the MgO and CaO do not show much leaching in red boles. Lesser leaching and salinity in the red boles is indicated by the higher values of calcification and lower values of salinization. The SiO2–Al2O3–Fe2O3 plot indicates that red bole samples are close to the basalt field, while the weathered upper basalt is more kaolinized than the weathered lower basalt. These observations reveal that the post-formational weathering processes have least affected the original palaeoweathering characters of the red bole horizon and hence the intrabasaltic palaeosols (weathering horizons) can effectively be used to constrain the palaeoweathering and palaeoclimates during the continental flood basalt episodes in the geologic past. 相似文献
5.
Sayyed Hamid Mesbah Mehrdad Mohammadnia Sayyed Ahang Kowsar 《Hydrogeology Journal》2016,24(2):303-317
In southern Iran’s Gareh Bygone Plain, water-supply qanats in four mixed farming communities were desiccated by over-pumping of illegal dug wells throughout the area. Emergency situations developed, resulting in city-ward migration. Since 1983, 193 million m3 of water has been supplied to those communities by floodwater spreading (FWS) to facilitate spate irrigation of sandy rangeland (2,034 ha) and artificial recharge of groundwater (ARG), of which 76 % has recharged the aquifer. This resulted in a reverse migration of the population. The irrigated area in the 2010–2011 growing season increased 13.2 fold when compared to the pre-FWS period, and year-round forage for about 700 sheep has been provided since 1991. The ARG is a logical alternative to building large dams in Iran; 420,000 km2 of coarse-grained alluvium provides capacity to store 5,000 km3 of water, representing more than ten times the annual precipitation of the whole country. As the equivalent cost for building dams to accommodate that volume is estimated at US$12.5?×?1012, the potential value of the alluvium may be realized. ARG on the recharge areas of 33,000 of the desiccated qanats eventually could rejuvenate them. As agricultural commodities absorb 19 % of the monetary value of Iran’s imports, and ARG activities could supply the water to produce them, alluvium is even more valuable than oil, which provides foreign exchange. More importantly, ARG on 140,000 km2 of the alluvium could strengthen the capacity to adapt to droughts and reduce the number and impact of water-related emergency situations. 相似文献
6.
Marziyeh Tari Sayyed Ali Moussavi Zarandi Kheirollah Mohammadi Mohammad Reza Zare 《Marine pollution bulletin》2013
Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. 226Ra, 235U, 232Th, 40K and 137Cs analysis has been carried out in sand samples collected at six depth levels, from eight locations of the northern coast of Iran, Ramsar, using high-resolution gamma-ray spectroscopy. The average Specific activities of natural radionuclides viz., 226Ra, 235U, 232Th, 40K and 137Cs, in the 0–36 cm depth sand were found as: 19.2 ± 0.04, 2.67 ± 0.17, 17.9 ± 0.06, 337.5 ± 0.61 and 3.35 ± 0.12 Bq kg−1, respectively. The effects of organic matter content and pH value of sand samples on the natural radionuclide levels were also investigated. Finally, the measured radionuclide concentrations in the Ramsar beach were compared with the world average values, as reported by UNSCEAR (2000). None of the studied beaches were considered as a radiological risk. 相似文献
7.
Taura Usman H. Mahzari Pedram Sohrabi Mehran Al-Wahaibi Yahya Farzaneh Sayyed Amir 《Computational Geosciences》2022,26(5):1207-1222
Computational Geosciences - In heavy oil displacement by fluid injection, severe instability can occur due to the adverse mobility ratio, gravity segregation or compositional effects. However, when... 相似文献
8.
Karaji: mathematician and qanat master 总被引：1，自引：0，他引：1
9.
Masoud EDRAKI Sayyed Ahang KOWSAR 《山地科学学报》2007,4(2):136-145
Water is the most important limiting factor in the development of arid environments; therefore, optimization of water use is a necessity in desert reclamation projects. Evapotranspiration of a 6-year-old river red gum (Eucalyptus camaldulensis Dehnh.) plantation, located in a sedimentation basin of an artificial recharge of the Gareh Bygone Plain groundwater system in Iran’s southern Zagros Mountains, was studied during a 7-month period. A neutron moisture probe was used to monitor soil water changes in the root zone. Soil water depletion following rapid drainage for blocks receiving relatively high, medium and low volumes of floodwater were 809.6, 312.4, and 203.1 mm, respectively, for a 150-day period. Soil water potential during most of the study period was below -1.5 MPa. This study proves that river red gum in not a suitable species for desertification control where water conservation is of vital importance. Flood irrigation of trees on 8 Aug. 1991 provided the opportunity to throw doubt upon the claim of summer dormancy of river red gum. 相似文献
10.