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To overcome the limitations posed by the limited relevant data for recharge estimation in the Jordanian Yarmouk River basin, a mass balance methodology is developed which is simple and may be easily applied to other arid and semi-arid landscapes. This is done by integrating available climatic data with new rain-runoff relationship data, as measured using a specially designed and built artificial rainfall simulator, and changing soil moisture profiles through the hydrological year, as measured in the field. The amount of moisture in the soil after rainfall events changes as a result of both evaporation and of drainage into deeper levels (recharge). The soil moisture profiles at depth are evaluated using geophysical techniques that allow for the tracking of recharge fronts. After rainfall events, the distribution of its fate between runoff, evaporation and recharge is determined. Water in the soil beyond the field capacity can be demonstrated to mostly contribute to the ultimate groundwater recharge in the area. Water stored beyond the permanent wilting point is not considered to contribute significantly to the recharge regime. Because of the irregular nature of rainfall, the amount of recharge is found to be related to the spacing of wet and dry spells during the winter months more than the actual amount of rainfall. Prolonged dry periods allow for excess water to drain into the deeper soil and thus to the groundwater, and thus allow for more uptake following subsequent rainy events. Evaporation does not significantly contribute to the drying of the soils. Reanalysis of rainfall and evaporation data from previous years suggests that recharge rates range from 20 to 37 % of total rainfall amounts, as opposed to the currently assumed 5 %. [ABSTRACT FROM AUTHOR]

Abstract: Darwin''s “warm little pond”, where he envisioned life began, was perhaps metaphorical. However, it included the notion of separation, just as the Galápagos Islands are separated from mainland South America. We have studied a location where simple life flourishes far from other abundant life, i.e., a permanently damp surficial zone that is surrounded by stark desert in NE Jordan. NE Jordan is a young basaltic plateau with fresh outcrops. However, a positive-feedback process has produced local weathering at Biyar el Ghussein in the Tulul al Ashaqif area. Calcite, smectites, and goethite occur with parent minerals. Water that is inducing this weathering has come from rainfall, but the isotopic composition of abundant carbonate veins reveals a deep source, i.e., volcanogenic CO2. A local coincidence of groundwater and rising CO2 is inducing a positive-feedback process, enhancing a weakly perched water table through weathering of basalt. Additional perched water dissolves more volcanogenic CO2, accelerating decomposition of the basalt, and enlarging the aquiclude. [Copyright &y& Elsevier]

Chemical data are used to clarify the hydrogeological regime in the Mafraq area in northern Jordan, as well as to determine the status ofwater quality in the area. Groundwater from the shallow aquifer in the Mafraq area can be divided into two major groups according to geographical locations and chemical compositions. Water in the basaltic eastern part of the study area is characterized by the dominance of chloride, sulfate, sodium, and potassium, whereas waters in the limestone aquifers in the west are dominated by the same cations but have higher concentrations of bicarbonate. Stable isotopes show that the shallow aquifers contain a single water type which originated in a distinct climatic regime. This water type deviates from the Global Meteoric Water Line (MWL), as well as from the eastern Mediterranean meteoric water line. The waters are poor in tritium, and thus can be considered generally older than 50 years. Chemical mass balance models suggest that water is moving from the west towards the north of the study area. This suggests that waters from the different basins are separated from each other. Degradation of water quality can be attributed toagricultural fertilizers in most cases, although the waste-water treatment plant at Khirbet es Samra is a contributor to pollution in thesouthwestern part of the study area. [ABSTRACT FROM AUTHOR]

Solid friable residues (i.e. Ash) from combusted oil shale are a major environmental issue because they are highly enriched with toxic elements following combustion. The synchrotron based techniques X-ray Absorption Fine Structure (XAFS) were used for determining the changes in speciation of Chromium (Cr) and Vanadium (V) in the ash and its mixtures with Red soil and Phosphogypsum as additives, through one-year period of hydration process. The X-ray Absorption Near Edge Structure (XANES) qualitative results indicate that all mixtures exhibits similar patterns showing that Vanadium has remain as pentavalent state, on the contrary Chromium has dramatic decreased from hexavalent to trivalent. This change in Cr speciation became clearer with increasing hydration period. Therefore, the results confirmed the advantage of the hydration process in the Cr(VI) reduction which might be due the domination of carbonate phase within all mixtures, thus hydration caused carbonate dissolution that increase the pH toward more alkaline which caused the Cr(IV) reduction into less-harmful and less mobile Cr(III). This increase in pH was not in favor of changing the V(V) into V(IV) due to its large stability field V(V). The Extend X-ray Absorption Fine Structure (EXAFS) analysis showed that Cr exhibiting a coordination shell of C-atoms as first nearest neighbors backscattering atoms around Cr, and at C-atoms backscattering at medium range order. This confirmed the domination of carbonate media through the best fitting of Cr-C. Which might be attributed to the more alkaline conditions developed during saturation of water (hydration), that accelerates of the reduction of Cr(VI) into Cr(III). This means simply that hydration of the ash can reduce the presence of harmful Cr(VI) in these ash tailings., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors. Published by Elsevier Ltd.)

The Fertile Crescent, its hilly flanks and surrounding drylands has been a critical region for studying how climate has influenced societal change, and this review focuses on the region over the last 20,000 years. The complex social, economic, and environmental landscapes in the region today are not new phenomena and understanding their interactions requires a nuanced, multidisciplinary understanding of the past. This review builds on a history of collaboration between the social and natural palaeoscience disciplines. We provide a multidisciplinary, multiscalar perspective on the relevance of past climate, environmental, and archaeological research in assessing present day vulnerabilities and risks for the populations of southwest Asia. We discuss the complexity of palaeoclimatic data interpretation, particularly in relation to hydrology, and provide an overview of key time periods of palaeoclimatic interest. We discuss the critical role that vegetation plays in the human-climate-environment nexus and discuss the implications of the available palaeoclimate and archaeological data, and their interpretation, for palaeonarratives of the region, both climatically and socially. We also provide an overview of how modelling can improve our understanding of past climate impacts and associated change in risk to societies. We conclude by looking to future work, and identify themes of "scale" and "seasonality" as still requiring further focus. We suggest that by appreciating a given locale's place in the regional hydroscape, be it an archaeological site or palaeoenvironmental archive, more robust links to climate can be made where appropriate and interpretations drawn will demand the resolution of factors acting across multiple scales. This article is categorized under:Human Water > Water as Imagined and RepresentedScience of Water > Water and Environmental ChangeWater and Life > Nature of Freshwater Ecosystems., Competing Interests: The authors have declared no conflicts of interest for this article., (© 2019 The Authors. WIREs Water published by Wiley Periodicals, Inc.)

Multi-year instrumental records for input, throughflow and output waters of the Lilburn Cave system provide control on denudation rates as they respond to seasonal and spatial variability. Data suggest that maximum denudation is in the late fall and early winter. This is when non-snowmelt discharge is at its maximum. At lower discharge rates the volume of water moving through the cave system is the limiting control on the volume of denudation. During periods of snowmelt the limiting control is the rate at which the calcite dissolves. This is probably the result of water flowing through wider channels during these times. Based on instrumental measurements, there is considerable variation in terms of where denudation occurs inside the cave. The loci of dissolution change from year to year. This is to be expected in the dynamic environment of the cave where materials shift routinely. This variability should be studied over longer periods of time in order to more fully understand its extent. The relatively small area of carbonate exposure relative to the area of the drainage basin gives rise to relatively high denudation rates. The carbonate is being removed at a rate of about 5000 metric tons per year, or at about 830 mm/y. This is about five times the rate reported in the humid karst regions of Malaysia. This information indicates that the relative proportion of carbonate in the drainage basin needs to be considered when trying to estimate denudation in other areas.