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1.
Brückner Florian Bahls Rebecca Alqadi Mohammad Lindenmaier Falk Hamdan Ibraheem Alhiyari Mohammad Atieh Ala’a 《Hydrogeology Journal》2021,29(8):2789-2802
Hydrogeology Journal - In 2017, a comprehensive review of groundwater resources in Jordan was carried out for the first time since 1995. The change in groundwater levels between 1995 and 2017 was... 相似文献
2.
Luca M. Abbühl Kevin P. Norton John D. Jansen Fritz Schlunegger Ala Aldahan Göran Possnert 《地球表面变化过程与地形》2011,36(11):1464-1473
A steep escarpment edge, deep gorges and distinct knickzones in river profiles characterize the landscape on the Western Escarpment of the Andes between ~5°S and ~18°S (northern Peru to northern Chile). Strong north–south and east–west precipitation gradients are exploited in order to determine how climate affects denudation rates in three river basins spanning an otherwise relatively uniform geologic and geomorphologic setting. Late Miocene tectonics uplifted the Meseta/Altiplano plateau (~3000 m a.s.l.), which is underlain by a series of Tertiary volcanic‐volcanoclastic rocks. Streams on this plateau remain graded to the Late Miocene base level. Below the rim of the Meseta, streams have responded to this ramp uplift by incising deeply into fractured Mesozoic rocks via a series of steep, headward retreating knickzones that grade to the present‐day base level defined by the Pacific Ocean. It is found that the Tertiary units on the plateau function as cap‐rocks, which aid in the parallel retreat of the sharp escarpment edge and upper knickzone tips. 10Be‐derived catchment denudation rates of the Rio Piura (5°S), Rio Pisco (13°S) and Rio Lluta (18°S) average ~10 mm ky?1 on the Meseta/Altiplano, irrespective of precipitation rates; whereas, downstream of the escarpment edge, denudation rates range from 10 mm ky?1 to 250 mm ky?1 and correlate positively with precipitation rates, but show no strong correlation with hillslope angles or channel steepness. These relationships are explained by the presence of a cap‐rock and climate‐driven fluvial incision that steepens hillslopes to near‐threshold conditions. Since escarpment retreat and the precipitation pattern were established at least in the Miocene, it is speculated that the present‐day distribution of morphology and denudation rates has probably remained largely unchanged during the past several millions of years as the knickzones have propagated headward into the plateau. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
3.
Nourani Vahid Elkiran Gozen Abdullahi Jazuli Tahsin Ala 《Natural Resources Research》2019,28(4):1217-1238
Natural Resources Research - Solar radiation data are crucial for the design and evaluation of solar energy systems, climatic studies, water resources management, estimating crop productivity, etc.... 相似文献
4.
Authigenic vivianite and siderite microconcretions were found, respectively, in hemipelagic and deltaic facies of 600-m-long BDP-98 sediment section from Lake Baikal. Textural investigations of these microconcretions show that they are typically <1 mm in size, irregular in shape and composed of aggregated crystallites. Dissimilar orientation of vivianite and siderite crystallites suggests formation at different depths in the sediment; up to tens of centimeters for vivianite and tens of meters for siderite. Chemical analyses of both the vivianite and the siderite indicate cation composition characterized by minor amounts of Mn, Ca and Mn apart from the dominating Fe. Rather limited and distinctive carbon isotopic composition of the siderite, with δ
13CVPDB values between about +13 and +16‰, implies formation of the mineral in the methanogenic zone of diagenesis. Isotopic composition of oxygen in the siderite (δ
18OVPDB values between about −10 and -11‰ ) is consistent with crystallization temperature at about 10–30°C and water δ
18OSMOW values between about −10 and -16‰ . The distribution of the authigenic minerals in the section suggests changes in both sedimentary facies and climate, where vivianite formation was controlled by hemipelagic depositional conditions during the Pliocene and Quaternary, whereas siderite reflects impact of deltaic conditions during the Miocene. 相似文献
5.
Variation in the concentrations of iodine-129 (129I, T1/2=15.7 Myr), a low-level radioactive component of nuclear fuel waste, is documented in surface waters and depth profiles collected during 2001 along a transect from the Norwegian Coastal Current to the North Pole. The surface waters near the Norwegian coast are found to have 20 times higher 129I concentration than the surface waters of the Arctic Ocean. The depth profiles of 129I taken in the Arctic Ocean reveal a sharp decline in the concentration to a depth of about 300-500 m followed by a weaker gradient extending down to the bottom. A twofold increase in the 129I concentration is observed in the upper 1000 m since 1996. Based on known estimates of marine transient time from the release sources (the nuclear reprocessing facilities at La Hague, France, and Sellafield, UK), a doubling in the 129I inventory of the top 1000 m of the Arctic Ocean is expected to occur between the years 2001 and 2006. As 129I of polar mixed layer and Atlantic layer of the Arctic Ocean is ventilated by the East Greenland Current into the Nordic Seas and North Atlantic Ocean, further dispersal and increase of the isotope concentration in these regions will be encountered in the near future. 相似文献
6.
Hamid M. K. Al-Naimiy Ala A. J. Al-Douri Abdalla A. Alnajjar Umran Inan 《Earth, Moon, and Planets》2009,104(1-4):189-193
The proposed research project is aiming for providing basic data for quantitative comparison of lightning-induced disturbances of the ionosphere and the radiation belts in the American, European and Asia sectors. Most of the current data on such phenomena has so far been obtained in the western hemisphere, and the weight of scientific information indicates that lightning-induced effects at high altitudes and in the radiation belts may dominate other processes on a global scale. The proposed research project will facilitate the establishment and conduct of Very Low Frequency observations in the United Arab Emirates as a part of the Asia sector, thus providing a basis for comparison to facilitate global extrapolations and conclusions. Under the proposed project, Stanford University partners with Sharjah University, deploying one of their Very Low Frequency receivers at Sharjah University campus. Sharjah University provides the data digitization and recording equipment to facilitate continuous acquisition of the data. All data from the proposed project will be available for analysis over the Internet, and a series of annual visits are planned to maximize interactions and information exchange between the two universities. 相似文献
7.
Testing a spatially distributed tracer‐aided runoff model in a snow‐influenced catchment: Effects of multicriteria calibration on streamwater ages 
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下载免费PDF全文 Thea I. Piovano Doerthe Tetzlaff Pertti Ala‐aho Jim Buttle Carl P. J. Mitchell Chris Soulsby 《水文研究》2018,32(20):3089-3107
Integrating stable isotope tracers into rainfall‐runoff models allows investigation of water partitioning and direct estimation of travel times and water ages. Tracer data have valuable information content that can be used to constrain models and, in integration with hydrometric observations, test the conceptualization of catchment processes in model structure and parameterization. There is great potential in using tracer‐aided modelling in snow‐influenced catchments to improve understanding of these catchments' dynamics and sensitivity to environmental change. We used the spatially distributed tracer‐aided rainfall‐runoff (STARR) model to simulate the interactions between water storage, flux, and isotope dynamics in a snow‐influenced, long‐term monitored catchment in Ontario, Canada. Multiple realizations of the model were achieved using a combination of single and multiple objectives as calibration targets. Although good simulations of hydrometric targets such as discharge and snow water equivalent could be achieved by local calibration alone, adequate capture of the stream isotope dynamics was predicated on the inclusion of isotope data in the calibration. Parameter sensitivity was highest, and most local, for single calibration targets. With multiple calibration targets, key sensitive parameters were still identifiable in snow and runoff generation routines. Water ages derived from flux tracking subroutines in the model indicated a catchment where runoff is dominated by younger waters, particularly during spring snowmelt. However, resulting water ages were most sensitive to the partitioning of runoff sources from soil and groundwater sources, which was most realistically achieved when isotopes were included in the calibration. Given the paucity of studies where hydrological models explicitly incorporate tracers in snow‐influenced regions, this study using STARR is an important contribution to satisfactorily simulating snowpack dynamics and runoff generation processes, while simultaneously capturing stable isotope variability in snow‐influenced catchments. 相似文献
8.
In this study, the spatial and temporal variabilities of terrestrial water storage anomaly (TWSA) and snow water equivalent anomaly (SWEA) information obtained from the Gravity Recovery and Climate Experiment (GRACE) twin satellites data were analysed in conjunction with multisource snow products over several basins in the Canadian landmass. Snow water equivalent (SWE) data were extracted from three different sources: Global Snow Monitoring for Climate Research version 2 (GlobSnow2), Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), and Canadian Meteorological Centre (CMC). The objective of the study was to understand whether SWE variations have a significant contribution to terrestrial water storage anomalies in the Canadian landmass. The period was considered from December 2002 to March 2011. Significant relationships were observed between TWSA and SWEA for most of the 15 basins considered (53% to 80% of the basins, depending on the SWE products considered). The best results were obtained with the CMC SWE products compared with satellite-based SWE data. Stronger relationships were found in snow-dominated basins (Rs > = 0.7), such as the Liard [root mean square error (RMSE) = 21.4 mm] and Peace Basins (RMSE = 26.76 mm). However, despite high snow accumulation in the north of Quebec, GRACE showed weak or insignificant correlations with SWEA, regardless of the data sources. The same behaviour was observed in the Western Hudson Bay basin. In both regions, it was found that the contribution of non-SWE compartments including wetland, surface water, as well as soil water storages has a significant impact on the variations of total storage. These components were estimated using the Water-Global Assessment and Prognosis Global Hydrology Model (WGHM) simulations and then subtracted from GRACE observations. The GRACE-derived SWEA correlation results showed improved relationships with three SWEA products. The improvement is particularly important in the sub-basins of the Hudson Bay, where very weak and insignificant results were previously found with GRACE TWSA data. GRACE-derived SWEA showed a significant relationship with CMC data in 93% of the basins (13% more than GRACE TWSA). Overall, the results indicated the important role of SWE on terrestrial water storage variations. 相似文献
9.
Along the northeast Greenland continental margin, bedrock on interfjord plateaus is highly weathered, whereas rock surfaces in fjord troughs are characterized by glacial scour. Based on the intense bedrock weathering and lack of glacial deposits from the last glaciation, interfjord plateaus have long been thought to be ice-free throughout the last glacial maximum (LGM). In recent years there is growing evidence from shelf and fjord settings that the northeast Greenland continental margin was more extensively glaciated during the LGM than previously thought. However, little is still known from interfjord settings. We present cosmogenic 10Be data from meltwater channels and weathered sandstone outcrops on Jameson Land, an interfjord highland north of Scoresby Sund. The mean exposure age of samples from channel beds (n = 3) constrains on the onset of deglaciation on interior Jameson Land to 18.5 ± 1.3–21.4 ± 1.9 ka (for erosion conditions of 0–10 mm/ka, respectively). This finding adds to growing evidence that the northeast Greenland continental margin was more heavily glaciated during the LGM than previously thought. 相似文献
10.
This paper is concerned with the modeling of particle transport at the Safaniya sea area. It presents the modeling aspects of a marine environment impact study at the Safaniya offshore facility. The offshore facility has continuous discharges of hypochlorite concentration, sanitary waste water, oily water, brine, and sea cooling water. The dispersion of pollutants in the Safaniya sea area is analyzed with the aid of a particle dispersion model. The dispersion of a continuous discharge from the offshore platform is simulated for typical meteorological conditions during the seasons of winter, spring, summer, and fall. Maximum average pollutant concentrations are obtained at various depths. A time series of pollutant concentration near the location of the discharge is constructed. The sea areas affected by the discharge are computed. The dispersion of a hypochlorite concentrate with concentration of 2 ppm is analyzed. Results indicate that the average chlorine concentration has a maximum of 0.27 × 10−2 ppm. 相似文献