The zircon-age distribution in metamorphic rocks of the Taratash block,Southern Urals (an initial provenance signal)     

Al. V. Tevelev  V. M. Mosejchuk  Ark. V. Tevelev  B. B. Shkursky 《Moscow University Geology Bulletin》2017,72(5):314-319

A concept for the interpretation of the initial provenance signal in rocks of the Taratash block (in the Southern Urals) using the zircon isotope dating of the Archean and Early Proterozoic igneous and metamorphic rocks was substantiated and carried out. Based on 132 zircon-age datings with a discordance of as much as 10%, a probability-density diagram was compiled first to compare these age data with those of detrital zircons from Lower Riphean sandstones of the Ai Formation and, secondly, with the probability density of zircon ages in metamorphic rocks of the Aleksandrovsk block, which is located to the east. The similarity of the distributions was verified using the Kolmogorov–Smirnov test.  相似文献   

Performance evaluation of HWRF model during post monsoon tropical cyclone Nilofar     

Sultan Al-Yahyai  Abeer Aulad Thani  Noura Al-kaabi  Khalifa Al-Sudairi  Badriya Al-Mawali  Issa Al Amri 《Arabian Journal of Geosciences》2017,10(4):76

An accurate tropical cyclone track and intensity forecast is very important for disaster management. Specialized numerical prediction models have been recently used to provide high-resolution temporal and special forecasts. Hurricane Weather Research and Forecast (HWRF) model is one of the emerging numerical models for tropical cyclone forecasting. This study evaluates the performance of HWRF model during the post monsoon tropical cyclone Nilofar on the north Indian Ocean basin. The evaluation uses the best track data provided by the Indian Meteorological Department (IMD) and the Joint Typhoon Warning Centre (JTWC). Cyclone track, central pressure, and wind speed are covered on this evaluation. Generally, HWRF was able to predict the Nilofar track with track error less than 230 km within the first 66 h of forecast time span. HWRF predicted more intense tropical cyclone. It predicted the lowest central pressure to be 922 hPa while it reached 950 hPa according to IMD and 937 hPa according to JTWC. Wind forecast was better as it predicted maximum wind speed of 122 kt while it reached 110 and 115 kt according to IMD and JTWC, respectively.  相似文献   

Comparison between inductively coupled plasma and X-ray fluorescence performance for Pb analysis in environmental soil samples     

Ali Al Maliki  Ahmed Kadhim Al-lami  H. M. Hussain  Nadhir Al-Ansari 《Environmental Earth Sciences》2017,76(12):433

Comparison of two conventional analytical techniques such as X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) for measuring Pb concentrations in soil samples was achieved using field and laboratory work. Seventy-three samples were collected from urban areas surrounding the large lead smelter at South Australia, as an indicator of the environment impact of smelter activity. Soil Pb concentrations were determined using hand-held XRF analyser under laboratory conditions. ICP-MS analysis on digested soils (using a microwave-assisted nitric acid digestion-extraction) was applied to validate p-XRF data. The analysis showed that Pb concentrations determined by XRF correlated with high linearity with Pb concentrations determined by ICP-MS measurements (R ² = 0.89). Statistical test (t test) was applied to the data of both methods applied without any significant difference between the two techniques. These results indicated that ICP-MS corroborated XRF for Pb soil measurements and suggests that XRF was a reliable and quick alternative to traditional analytical methods in studies of environmental health risk assessment, allowing for much larger sampling regimes in relatively shorter times and could be applied in the field.  相似文献   

Environmental assessment of soil,groundwater, and surface water quality in the south of the Riyadh,Saudi Arabia     

Abeer. Sh. Salman  Ali Al Dosari  Faisal K. Zaidi  Oumar Allafouza Loni 《Arabian Journal of Geosciences》2017,10(22):490

To understand the impact of the influence of treated wastewater, a study was undertaken in the downstream side of Wadi Hanifa in the southern part of Riyadh City in Saudi Arabia. Chemical elements from 17 groundwater samples, 9 surface water samples (treated wastewater), and 14 soil samples were analyzed. Water facies analyses showed that both groundwater and surface water belong to the SO₄-Cl class. However, the groundwater is characterized by high salinity (average value of 3547 mg/l), which may be result of the greater rock-water interaction and limited rainfall recharge. The NO₃ values are also high in the groundwater samples (average value of 40 mg/l) and are mainly attributed to the agricultural practices in the study area. The surface water samples (treated wastewater from the plant) shows an average salinity value of 1232 mg/l and is better suited for irrigation purposes. Heavy elements analyzed in the soil samples show high concentrations of all the elements except Mn and Ni as compared to their background concentration. Enrichment factor and index of geoaccumulation calculated from the soil samples indicate that they are severely enriched with respect to Cd and Se. The spatial distribution maps were prepared based on kriging interpolation technique to estimate the concentrations of the analyzed elements at unknown locations. The treated wastewater in the study area is better suited for agricultural and domestic activities as compared to groundwater.  相似文献   

Rangeland hydrology and erosion model (RHEM) enhancements for applications on disturbed rangelands   总被引：2，自引：0，他引：2       下载免费PDF全文

Osama Z. Al‐Hamdan  Mariano Hernandez  Frederick B. Pierson  Mark A. Nearing  C. Jason Williams  Jeffrey J. Stone  Jan Boll  Mark A. Weltz 《水文研究》2015,29(3):445-457

The rangeland hydrology and erosion model (RHEM) is a new process‐based model developed by the USDA Agricultural Research Service. RHEM was initially developed for functionally intact rangelands where concentrated flow erosion is minimal and most soil loss occurs by rain splash and sheet flow erosion processes. Disturbance such as fire or woody plant encroachment can amplify overland flow erosion by increasing the likelihood of concentrated flow formation. In this study, we enhanced RHEM applications on disturbed rangelands by using a new approach for the prediction and parameterization of concentrated flow erosion. The new approach was conceptualized based on observations and results of experimental studies on rangelands disturbed by fire and/or by tree encroachment. The sediment detachment rate for concentrated flow was calculated using soil erodibility and hydraulic (flow width and stream power) parameters. Concentrated flow width was calculated based on flow discharge and slope using an equation developed specifically for disturbed rangelands. Soil detachment was assumed to begin with concentrated flow initiation. A dynamic erodibility concept was applied where concentrated flow erodibility was set to decrease exponentially during a run‐off event because of declining sediment availability. Erodibility was estimated using an empirical parameterization equation as a function of vegetation cover and surface soil texture. A dynamic partial differential sediment continuity equation was used to model the total detachment rate of concentrated flow and rain splash and sheet flow. The enhanced version of the model was evaluated against rainfall simulation data for three different sites that exhibit some degree of disturbance by fire and/or by tree encroachment. The coefficient of determination (R²) and Nash–Sutcliffe efficiency were 0.78 and 0.71, respectively, which indicates the capability of the model using the new approach for predicting soil loss on disturbed rangeland. By using the new concentrated flow modelling approach, the model was enhanced to be a practical tool that utilizes readily available vegetation and soil data for quantifying erosion and assessing erosion risk following rangeland disturbance. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Model-based imputation of missing data from the 122 Cities Mortality Reporting System (122 CMRS)     

Paula Moraga  Al Ozonoff 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(5):1499-1507

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A macroseismic study of the Taldy-Sai caravanserai in the Kara-Bura River valley (Talas basin,Kyrgyzstan)     

A.M. Korjenkov  K.Sh. Tabaldiev  Al.V. Bobrovskii  Ar.V. Bobrovskii  E.M. Mamyrov  L.A. Orlova 《Russian Geology and Geophysics》2009,50(1):63-69

We report a macroseismic study of a ruined medieval building, a small caravanserai located along the caravan way from the Talas valley to the Chatkal and Fergana valleys in Kyrgyzstan. The ruins document several events in which the caravanserai was destroyed, apparently during earthquakes, and was rebuilt or repaired. The earliest earthquake occurred soon after the building was put up, about 400 years ago, according to radiocarbon dating of charcoal, and another event shook the area between 400 and 50 years BP. After being damaged in the ultimate earthquake, in the middle of the 20th century, the building was eventually abandoned.  相似文献   

Impact of the Use of Reclaimed Water on the Quality of Groundwater Resources in the Jordan Valley,Jordan     

Mustafa Al Kuisi  Taiseer Aljazzar  Thomas Rüde  Armin Margane 《洁净——土壤、空气、水》2008,36(12):1001-1014

The use of reclaimed water and its impact on groundwater quality in the middle and southern parts of the Jordan Valley are investigated. The chemical analyses indicate that nitrate and bacteriological pollution is widespread, and thus, seriously affects groundwater use. During the study, 365 water samples were collected from wells and springs to determine the water chemistry and the extent of nitrate pollution. Three hydrochemical facies are identifed, i. e., (Ca–(Mg)–Na–HCO₃), (Ca–Na–SO₄–Cl) and (Ca–Na–Cl). The change of facies is accompanied by a gradual increase in the groundwater total dissolved solids (TDS), which is mainly controlled by evaporates and carbonates dissolution in the aquifer matrix. Water analyses indicate that the shallow aquifer in the study area is affected by non‐point pollution sources, primarily from natural (manure) and chemical nitrogen (N)‐fertilizers and treated wastewater used for agriculture. The concentration of nitrate in the groundwater ranges from 10 to 355 mg/L. Considerable seasonal fluctuations in groundwater quality are observed as a consequence of agricultural practices and other factors such as annual rainfall distribution and the Zarqa River flow. The noticeable levels of total coliform and Escherichia coli in the northern part of the study area may be attributed to contamination from the urban areas, intensive livestock production, and illegal dumping of sewage. Heavy metal concentrations in all samples were found to be significantly lower than the permissible limits for drinking water standards.  相似文献   

The water balance of the Dead Sea: an integrated approach     

Radwan A. Al‐Weshah 《水文研究》2000,14(1):145-154

The Dead Sea is the lowest spot on Earth. It is a closed saline lake located in the middle of the Jordan Rift Valley between Lake Tiberias and the Red Sea. Its major tributaries are the Jordan River itself and the Dead Sea side wadis. The Dead Sea has a unique ecosystem and its water has curative, industrial and recreational significance. The level of the Dead Sea has been continuously falling since the early 1930s at an average rate of 0·7 m per year. The water level, as of February 1998, is about 410·9 m below mean sea level. In this paper, a water balance model is developed for the Dead Sea by considering different hydrological components of this water balance, including precipitation, runoff, evaporation and groundwater flow. This model is calibrated based on historical levels of the Dead Sea. Different scenarios are investigated, including the proposed Dead Sea–Red Sea Canal. This project is supposed to halt the shrinking of the Dead Sea and restore it to pre‐1950 levels in the next century. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Application of a mixture distribution of extreme values to earthquake magnitudes in Iraq and conterminous regions     

Khalid J. Fahmi  Jamal N. Al Abbasi 《Geophysical Journal International》1991,107(2):209-217

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