Journal articles on the topic 'Recharge accumulateur'
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1
Zamora, Hector A., Christopher J. Eastoe, Jennifer C. McIntosh, and Karl W. Flessa. "Groundwater Origin and Dynamics on the Eastern Flank of the Colorado River Delta, Mexico." Hydrology 8, no. 2 (May 11, 2021): 80. http://dx.doi.org/10.3390/hydrology8020080.
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Isotope data and major ion chemistry were used to identify aquifer recharge mechanisms and geochemical evolution of groundwaters along the US–Mexico border. Local recharge originates as precipitation and occurs during winter through preferential infiltration pathways along the base of the Gila Range. This groundwater is dominated by Na–Cl of meteoric origin and is highly concentrated due to the dissolution of soluble salts accumulated in the near-surface. The hydrochemical evolution of waters in the irrigated floodplain is controlled by Ca–Mg–Cl/Na–Cl-type Colorado River water. However, salinity is increased through evapotranspiration, precipitation of calcite, dissolution of accumulated soil salts, de-dolomitization, and exchange of aqueous Ca2+ for adsorbed Na+. The Na–Cl-dominated local recharge flows southwest from the Gila Range and mixes with the Ca–Mg–Cl/Na–Cl-dominated floodplain waters beneath the Yuma and San Luis Mesas. Low 3H suggests that recharge within the Yuma and San Luis Mesas occurred at least before the 1950s, and 14C data are consistent with bulk residence times up to 11,500 uncorrected 14C years before present. Either the flow system is not actively recharged, or recharge occurs at a significantly lower rate than what is being withdrawn, leading to aquifer overdraft and deterioration.
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Sherif, Mohsen, Ahmed Sefelnasr, Muhammad Al Rashed, Dalal Alshamsi, Faisal K. Zaidi, Khaled Alghafli, Faisal Baig, et al. "A Review of Managed Aquifer Recharge Potential in the Middle East and North Africa Region with Examples from the Kingdom of Saudi Arabia and the United Arab Emirates." Water 15, no. 4 (February 13, 2023): 742. http://dx.doi.org/10.3390/w15040742.
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Groundwater extraction in most Middle East and North Africa (MENA) countries far exceeds its renewability, which ranges from 6% to 100%. Freshwater resources to support food production are very limited in this region. Future climate predictions include more consistent and longer wet periods with increasing surplus rainfall, which will enhance flood and flash flood occurrences in the MENA. Demand management of groundwater resources and managed aquifer recharge (MAR, also called groundwater replenishment, water banking, and artificial recharge, is the purposeful recharge of water to aquifers for subsequent recovery or environmental benefits) represent essential strategies to overcome the challenges associated with groundwater depletion and climate change impacts. Such strategies would enable the development of groundwater resources in the MENA region by minimizing the stress placed on these resources, as well as reducing deterioration in groundwater quality. Groundwater augmentation through recharge dams is a common practice in different countries around the globe. Most dams in the MENA region were built to enhance groundwater recharge, and even the few protection dams also act as recharge dams in one way or another. However, the operating systems of these dams are mostly dependent on the natural infiltration of the accumulated water in the reservoir area, with limited application of MAR. This review presents analyses of groundwater renewability and the effectiveness of recharge dams on groundwater recharge, as well as the potential of MAR technology. This study indicates that the recharge efficiency of dam’s ranges between 15 to 47% and is clustered more around the lower limit. Efficiency is reduced by the clogging of the reservoir bed with fine materials. Therefore, there is a need to improve the operation of dams using MAR technology.
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Brkić, Željka, Mladen Kuhta, Tamara Hunjak, and Ozren Larva. "Regional Isotopic Signatures of Groundwater in Croatia." Water 12, no. 7 (July 13, 2020): 1983. http://dx.doi.org/10.3390/w12071983.
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Tracer methods are useful for investigating groundwater travel times and recharge rates and analysing impacts on groundwater quality. The most frequently used tracers are stable isotopes and tritium. Stable isotopes of oxygen (δ18O) and hydrogen (δ2H) are mainly used as indicators of the recharge condition. Tritium (3H) is used to estimate an approximate mean groundwater age. This paper presents the results of an analysis of stable isotope data and tritium activity in Croatian groundwater samples that were collected between 1997 and 2014 at approximately 100 sites. The composition of the stable isotopes of groundwater in Croatia originates from recent precipitation and is described using two regional groundwater lines. One of them is applied to groundwater accumulated in the aquifers in the Pannonian part of Croatia and the other is for groundwater accumulated in the Dinaric karst of Croatia. The isotope content shows that the studied groundwater is mainly modern water. A mix of sub-modern and modern water is mostly accumulated in semi-confined porous aquifers in northern Croatia, deep carbonate aquifers, and (sub)thermal springs.
4
Puida, V. "DEVICE FOR CONTROLLING PARAMETERS OF ACCUMULATOR BATTERIES AND THE CORRESPONDING DIRECT CURRENT NETWORK." Computer systems and network 5, no. 1 (December 16, 2023): 89–95. http://dx.doi.org/10.23939/csn2023.01.089.
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Mobile devices for information, control and telemetry systems are powered by mobile generators through AC to DC converters, by batteries or, if possible, directly by solar panels. Solar panels typically work in a system that involves the usage of batteries to keep the systems running when the solar panels are not working or not providing enough power. The batteries can be recharged from the panels themselves if the solar panels have sufficient power or from an external direct current source. Also, for some mobile devices, power systems are used only with batteries, which are recharged from generators or, if possible, from standard electrical networks. All these options of power supply systems for mobile devices require operational control of battery parameters and corresponding direct current networks. The paper proposes a device for monitoring the following parameters: voltage of the direct current network from which the mobile device is powered or the batteries are charged; battery charge current control; control of insulation resistance of direct current circuits; control of the voltage of chargers; monitoring the status of chargers; protection of batteries from deep discharge; control of the state of switching nodes. The device is implemented as a two-processor system based on STM32F103 microcontrollers. A non-contact sensor of the LEM LA 100-P type is used to measure the direct current, which generates an analog signal proportional to the value of the direct current. This signal is passed to a 16- bit analog-to-digital converter. Given that these microcontrollers have integrated 12-bit analog-to- digital converters, an external 16-bit analog-to-digital converter of the ADS1115 type is used to ensure the necessary accuracy of direct current and voltage measurement, which transmits information to the basic processor via the I2C interface. The basic processor implements the main operating modes of the device, and the local processor provides information exchange with the general mobile power supply system through the RS-485 interface. The device is equipped with an indication system based on an LCD indicator of the VS1602A type and functionally programmable single LED indicators, a local keyboard for selecting control modes, a USB port for connecting additional modules and a SWD port for programming the Flash memory of microcontrollers and debugging programs in real time. During operation, parameters of non-standard events are stored in the device's non-volatile memory. The software of the basic and local processors has been developed, which ensures the functioning of the device in basic modes and performs periodic self-diagnosis of the device. The obtained results can be used in scientific research and in the design of real automated power systems for mobile information systems. Keywords: power systems of mobile information systems, batteries, battery charging, microcontroller, LCD indicator, I2C interface, USB interface, RS-485 interface, SWD interface.
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Nigate, Fenta, Marc Van Camp, Alemu Yenehun, Ashebir Sewale Belay, and Kristine Walraevens. "Recharge–Discharge Relations of Groundwater in Volcanic Terrain of Semi-Humid Tropical Highlands of Ethiopia: The Case of Infranz Springs, in the Upper Blue Nile." Water 12, no. 3 (March 18, 2020): 853. http://dx.doi.org/10.3390/w12030853.
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The major springs in the Infranz catchment are a significant source of water for Bahir Dar City and nearby villages, while sustaining the Infranz River and the downstream wetlands. The aim of the research was to understand the hydrogeological conditions of these high-discharge springs and the recharge–discharge relations in the Infranz catchment. The Infranz catchment is covered by highly pervious and young quaternary volcanic rocks, consisting of blocky, fractured, and strongly vesicular scoriaceous basalt. At the surface, these rocks crop out as lineaments forming ridges, delimiting closed depressions in which water accumulates during the rainy season without causing surface runoff. Geology and geomorphology thus combine to produce very favorable conditions for groundwater recharge. Three groundwater recharge methods were applied to estimate groundwater recharge and the results were compared. Groundwater recharge was calculated to be 30% to 51% of rainfall. Rapid replenishment raises the groundwater level during the rainfall period, followed by a rapid decline during the dry season. Shallow local flow paths discharge at seasonal springs and streams, while more regional and deeper flow systems downstream sustain the high-discharge springs and perennial Infranz River. The uptake of 75% of spring water for the water supply of Bahir Dar City, local extraction for domestic and small-scale irrigation use from springs, rivers and hand-dug wells, encroaching farming, and overgrazing are exacerbating wetland degradation.
6
Sefelnasr, Ahmed, Abdel Azim Ebraheem, Muhammad Abrar Faiz, Xiaogang Shi, Khaled Alghafli, Faisal Baig, Muhammad Al-Rashed, Dalal Alshamsi, Munaver Basheer Ahamed, and Mohsen Sherif. "Enhancement of Groundwater Recharge from Wadi Al Bih Dam, UAE." Water 14, no. 21 (October 29, 2022): 3448. http://dx.doi.org/10.3390/w14213448.
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Groundwater and harvested rainwater represent the only conventional freshwater resources in the United Arab Emirates (UAE). Groundwater resources in Wadi Al Bih, UAE, are sustainable due to the low exploitation rate for domestic and agricultural purposes. Thus, the groundwater depletion in this area is far less than in other parts of the country. The Wadi Al Bih area is very important for achieving water security in UAE. Therefore, the possible measures of increasing groundwater recharge (e.g., managed aquifer recharge (MAR) methods) are investigated in this paper. The available water resource data were collected, reviewed, validated, and stored in a GIS database. Then, a GIS-based water budget model (WBM) was developed to evaluate the available groundwater resources in Wadi Al Bih and recharge sources. The analyses showed that only 49% of the accumulated rainwater behind the dam is recharging the underlying aquifer. Due to the absence of any direct recharge techniques, the remaining 51% is lost by direct evaporation (15%), and as soil moisture increases in the unsaturated zone (36%), it will subsequently evaporate or percolate depending on the precipitation pattern and air temperature. The results of the WBM indicated that the freshwater resources were decreasing at an alarming rate of approximately thirty-five million cubic meters (MCM) per year until 2019. The groundwater storage and salinity were governed by the rates and patterns of precipitation. For example, the recharge resulting from the two consecutive maximum monthly precipitation events in December 2019 and January 2020 has significantly increased the fresh groundwater reserve and slightly retreated the saline/brackish water toward the shoreline. Moreover, a Mann–Kendall trend analysis was conducted to assess the influence of precipitation, temperature, and evaporation on groundwater recharge. The outcomes suggested that climate variables had a significant effect on groundwater supplies. The mitigation measures include revising groundwater withdrawal rates based on the annual recharge and enhancing recharge using different MAR techniques and dam operation plans.
7
Bai, Tao, Wen-Ping Tsai, Yen-Ming Chiang, Fi-John Chang, Wan-Yu Chang, Li-Chiu Chang, and Kuang-Chih Chang. "Modeling and Investigating the Mechanisms of Groundwater Level Variation in the Jhuoshui River Basin of Central Taiwan." Water 11, no. 8 (July 27, 2019): 1554. http://dx.doi.org/10.3390/w11081554.
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Due to nonuniform rainfall distribution in Taiwan, groundwater is an important water source in certain areas that lack water storage facilities during periods of drought. Therefore, groundwater recharge is an important issue for sustainable water resources management. The mountainous areas and the alluvial fan areas of the Jhuoshui River basin in Central Taiwan are considered abundant groundwater recharge regions. This study aims to investigate the interactive mechanisms between surface water and groundwater through statistical techniques and estimate groundwater level variations by a combination of artificial intelligence techniques and the Gamma test (GT). The Jhuoshui River basin in Central Taiwan is selected as the study area. The results demonstrate that: (1) More days of accumulated rainfall data are required to affect variable groundwater levels in low-permeability wells or deep wells; (2) effective rainfall thresholds can be properly identified by lower bound screening of accumulated rainfall; (3) daily groundwater level variation can be estimated effectively by artificial neural networks (ANNs); and (4) it is difficult to build efficient models for low-permeability wells, and the accuracy and stability of models is worse in the proximal-fan areas than in the mountainous areas.
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Legchenko, A., C. Vincent, J. M. Baltassat, J. F. Girard, E. Thibert, O. Gagliardini, M. Descloitres, et al. "Monitoring water accumulation in a glacier using magnetic resonance imaging." Cryosphere Discussions 7, no. 3 (May 31, 2013): 2119–51. http://dx.doi.org/10.5194/tcd-7-2119-2013.
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Abstract. Tête Rousse is a small polythermal glacier located in the Mont Blanc area (French Alps) at an altitude of 3100 to 3300 m. Recent accumulation of melt water in the glacier was assumed to occur, but such accumulation had yet to be confirmed. Using Surface Nuclear Magnetic Resonance imaging (3-D-SNMR), we showed that the temperate part of the Tête Rousse glacier contains two separate water-filled caverns (central and upper caverns). In 2009, the central cavern contained about 55 000 m3 of water. Since 2010, the cavern is drained every year. Using 3-D-SNMR, we monitored the changes caused by this pumping in the water distribution within the glacier body. Twice a year, we carried out magnetic resonance imaging of the entire glacier and estimated the volume of water accumulated in the central cavern. Our results show the changes in cavern geometry and recharge rate: in two years, the central cavern lost about 73% of its initial volume, but 65% were lost in one year after the first pumping. We also observed that, after being drained, the cavern was recharged at an average rate of 20 to 25 m3 d−1 over the winter months and 120 to 180 m3 d−1 in summer. These observations illustrate how ice and water may refill englacial volume being emptied by artificial draining. Comparison of the 3-D-SNMR results with those obtained by drilling and pumping showed a very good correspondence, confirming the high reliability of 3-D-SNMR imaging.
9
Maliva, Robert G. "Groundwater banking: opportunities and management challenges." Water Policy 16, no. 1 (October 30, 2013): 144–56. http://dx.doi.org/10.2166/wp.2013.025.
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Groundwater banking is the use of aquifers to store water to balance seasonal or longer-term variations in supply and demand. The large storage capacity provided by aquifers can be a valuable tool for conjunctive use of surface water and groundwater as well as other elements of integrated water resources management. Successful groundwater banking requires favorable hydrogeological conditions to efficiently recharge, store, and abstract large volumes of water. Additionally, groundwater banking is also highly dependent upon water management and operational policies to ensure that stored water is not abstracted by other users and that the water accounting system of the bank remains in balance. Accumulated credits to withdraw water should not exceed the capacity of an aquifer to safely produce the water at the design rate-of-return for the bank. System participants need to have confidence that credits issued for recharge can be safely recovered when needed. Groundwater banking systems can cause significant local adverse impacts to other aquifer users and sensitive environments during recovery periods. Groundwater modeling is required to develop a sustainable management system that accounts for temporal and spatial variations in the impacts of both recharge and abstraction activities.
10
Reinecke, Robert, Hannes Müller Schmied, Tim Trautmann, Lauren Seaby Andersen, Peter Burek, Martina Flörke, Simon N. Gosling, et al. "Uncertainty of simulated groundwater recharge at different global warming levels: a global-scale multi-model ensemble study." Hydrology and Earth System Sciences 25, no. 2 (February 19, 2021): 787–810. http://dx.doi.org/10.5194/hess-25-787-2021.
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Abstract. Billions of people rely on groundwater as being an accessible source of drinking water and for irrigation, especially in times of drought. Its importance will likely increase with a changing climate. It is still unclear, however, how climate change will impact groundwater systems globally and, thus, the availability of this vital resource. Groundwater recharge is an important indicator for groundwater availability, but it is a water flux that is difficult to estimate as uncertainties in the water balance accumulate, leading to possibly large errors in particular in dry regions. This study investigates uncertainties in groundwater recharge projections using a multi-model ensemble of eight global hydrological models (GHMs) that are driven by the bias-adjusted output of four global circulation models (GCMs). Pre-industrial and current groundwater recharge values are compared with recharge for different global warming (GW) levels as a result of three representative concentration pathways (RCPs). Results suggest that projected changes strongly vary among the different GHM–GCM combinations, and statistically significant changes are only computed for a few regions of the world. Statistically significant GWR increases are projected for northern Europe and some parts of the Arctic, East Africa, and India. Statistically significant decreases are simulated in southern Chile, parts of Brazil, central USA, the Mediterranean, and southeastern China. In some regions, reversals of groundwater recharge trends can be observed with global warming. Because most GHMs do not simulate the impact of changing atmospheric CO2 and climate on vegetation and, thus, evapotranspiration, we investigate how estimated changes in GWR are affected by the inclusion of these processes. In some regions, inclusion leads to differences in groundwater recharge changes of up to 100 mm per year. Most GHMs with active vegetation simulate less severe decreases in groundwater recharge than GHMs without active vegetation and, in some regions, even increases instead of decreases are simulated. However, in regions where GCMs predict decreases in precipitation and where groundwater availability is the most important, model agreement among GHMs with active vegetation is the lowest. Overall, large uncertainties in the model outcomes suggest that additional research on simulating groundwater processes in GHMs is necessary.
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Dawes, W., R. Ali, S. Varma, I. Emelyanova, G. Hodgson, and D. McFarlane. "Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia." Hydrology and Earth System Sciences Discussions 9, no. 5 (May 10, 2012): 6063–99. http://dx.doi.org/10.5194/hessd-9-6063-2012.
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Abstract. The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south west Western Australia, provides approximately 60% of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15%. There is expected to be a continuing reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia. Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A Vertical Flux Manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on land cover type (e.g. native trees, plantation, cropping, urban, wetland), soil type, and taking into account the groundwater depth. These recharge estimates were accumulated on a daily basis for both observed and projected climate scenarios and used in a MODFLOW simulation with monthly stress periods. In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In the Dandaragan Plateau to the north-east of Perth there has been groundwater level rise since the 1970s associated with land clearing, and with rainfall projected to reduce the least in this area the groundwater levels are estimated to continue to rise. Along the coastal zone north of Perth there is an interaction between projected rainfall decline and legislated removal to pine forests. This results in areas of increasing recharge and rising water levels into the future despite a drying climate signal. To the south of Perth city there are large areas where groundwater levels are close to the land surface and not expected to change more than 1m upward or downward over the next two decades; it is beyond the accuracy of the model to conclude any definite trend. In the south western part of the study area, the patterns of groundwater recharge are dictated primarily by soil, geology and land cover. In the sandy Swan (northern boundary) and Scott Coastal Plains (southern boundary) there is little response to future climates, because groundwater levels are shallow and much rainfall is rejected recharge. The profile dries out more in summer but this allows more rainfall to infiltrate in winter. Until winter recharge is insufficient to refill the aquifers these areas will not experience significant falls in groundwater levels. On the Blackwood Plateau however, the combination of native vegetation and clayey surface soils that restrict possible infiltration and recharge mean the area is very sensitive to climate change. With low capacity for recharge and low storage in the aquifers, small reductions in recharge can lead to large reductions in groundwater levels. In the northern part of the study area both climate and land cover strongly influence recharge rates. Recharge under native vegetation is minimal and is relatively higher where grazing and pasture systems have been introduced after clearing of native vegetation. In some areas the low recharge values can be reduced to almost zero, even under dryland agriculture, if the future climate becomes very dry. In the Albany Area the groundwater resource is already over allocated, and the combination of existing permanent native vegetation with decreasing annual rainfall indicate reduced recharge. The area requires a reduction in groundwater abstraction to maintain the sustainability of the existing resource.
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Legchenko, A., C. Vincent, J. M. Baltassat, J. F. Girard, E. Thibert, O. Gagliardini, M. Descloitres, et al. "Monitoring water accumulation in a glacier using magnetic resonance imaging." Cryosphere 8, no. 1 (January 28, 2014): 155–66. http://dx.doi.org/10.5194/tc-8-155-2014.
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Abstract. Tête Rousse is a small polythermal glacier located in the Mont Blanc area (French Alps) at an altitude of 3100 to 3300 m. In 1892, an outburst flood from this glacier released about 200 000 m3 of water mixed with ice, causing much damage. A new accumulation of melt water in the glacier was not excluded. The uncertainty related to such glacier conditions initiated an extensive geophysical study for evaluating the hazard. Using three-dimensional surface nuclear magnetic resonance imaging (3-D-SNMR), we showed that the temperate part of the Tête Rousse glacier contains two separate water-filled caverns (central and upper caverns). In 2009, the central cavern contained about 55 000 m3 of water. Since 2010, the cavern is drained every year. We monitored the changes caused by this pumping in the water distribution within the glacier body. Twice a year, we carried out magnetic resonance imaging of the entire glacier and estimated the volume of water accumulated in the central cavern. Our results show changes in cavern geometry and recharge rate: in two years, the central cavern lost about 73% of its initial volume, but 65% was lost in one year after the first pumping. We also observed that, after being drained, the cavern was recharged at an average rate of 20 to 25 m3 d−1 during the winter months and 120 to 180 m3 d−1 in summer. These observations illustrate how ice, water and air may refill englacial volume being emptied by artificial draining. Comparison of the 3-D-SNMR results with those obtained by drilling and pumping showed a very good correspondence, confirming the high reliability of 3-D-SNMR imaging.
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Bogena, H., R. Kunkel, C. Montzka, and F. Wendland. "Uncertainties in the simulation of groundwater recharge at different scales." Advances in Geosciences 5 (December 16, 2005): 25–30. http://dx.doi.org/10.5194/adgeo-5-25-2005.
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Abstract. Digital spatial data always imply some kind of uncertainty. The source of this uncertainty can be found in their compilation as well as the conceptual design that causes a more or less exact abstraction of the real world, depending on the scale under consideration. Within the framework of hydrological modelling, in which numerous data sets from diverse sources of uneven quality are combined, the various uncertainties are accumulated. In this study, the GROWA model is taken as an example to examine the effects of different types of uncertainties on the calculated groundwater recharge. Distributed input errors are determined for the parameters' slope and aspect using a Monte Carlo approach. Landcover classification uncertainties are analysed by using the conditional probabilities of a remote sensing classification procedure. The uncertainties of data ensembles at different scales and study areas are discussed. The present uncertainty analysis showed that the Gaussian error propagation method is a useful technique for analysing the influence of input data on the simulated groundwater recharge. The uncertainties involved in the land use classification procedure and the digital elevation model can be significant in some parts of the study area. However, for the specific model used in this study it was shown that the precipitation uncertainties have the greatest impact on the total groundwater recharge error.
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Meagher, RC, AJ Salvado, and DG Wright. "An analysis of the multilineage production of human hematopoietic progenitors in long-term bone marrow culture: evidence that reactive oxygen intermediates derived from mature phagocytic cells have a role in limiting progenitor cell self-renewal." Blood 72, no. 1 (July 1, 1988): 273–81. http://dx.doi.org/10.1182/blood.v72.1.273.273.
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Abstract To better understand the limited hematopoietic life span of human marrow “Dexter” cultures, we developed a miniaturized, two-stage culture system with which in vitro production of hematopoietic progenitors could be reproducibly detected and quantified. Light- density, gradient-separated human marrow cells were inoculated into Leighton slide tubes, and adherent (“stromal”) cell layers were allowed to develop on the removable coverslips within these tubes during an initial 4 weeks of culture. Once stromal cell layers were established, cultures were irradiated (800 cGy) to eliminate all residual hematopoietic progenitors. The cultures were then recharged with autologous, cryopreserved marrow cells (enriched for BFU-E and CFU-GM) to reconstitute stem cell populations and to initiate in vitro hematopoiesis. Most progenitor cells added to irradiated cultures were no longer detectable by clonal assays within one to four days after recharge. Nonetheless, stable populations of adherent BFU-E and CFU-GM became established in these cultures within 24 to 48 hours, and when the total numbers of progenitors (adherent and nonadherent) were measured at weekly intervals thereafter, it was evident that both BFU-E and CFU-GM were generated in vitro. However, progenitor cell production declined as neutrophils and macrophages accumulated in the cultures. Moreover, with this accumulation of mature myeloid cells, increasing levels of O2- and H2O2 could be detected in the cultures, and it was found that the addition of oxidant scavengers (catalase and mannitol) to culture media enhanced the weekly expansions of progenitor cell numbers that could be measured. These findings support the conclusion that reactive O2 intermediates generated by mature myeloid cells have a role in limiting the duration and extent of hematopoietic progenitor cell self-renewal in long-term “Dexter” cultures of human marrow.
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Meagher, RC, AJ Salvado, and DG Wright. "An analysis of the multilineage production of human hematopoietic progenitors in long-term bone marrow culture: evidence that reactive oxygen intermediates derived from mature phagocytic cells have a role in limiting progenitor cell self-renewal." Blood 72, no. 1 (July 1, 1988): 273–81. http://dx.doi.org/10.1182/blood.v72.1.273.bloodjournal721273.
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To better understand the limited hematopoietic life span of human marrow “Dexter” cultures, we developed a miniaturized, two-stage culture system with which in vitro production of hematopoietic progenitors could be reproducibly detected and quantified. Light- density, gradient-separated human marrow cells were inoculated into Leighton slide tubes, and adherent (“stromal”) cell layers were allowed to develop on the removable coverslips within these tubes during an initial 4 weeks of culture. Once stromal cell layers were established, cultures were irradiated (800 cGy) to eliminate all residual hematopoietic progenitors. The cultures were then recharged with autologous, cryopreserved marrow cells (enriched for BFU-E and CFU-GM) to reconstitute stem cell populations and to initiate in vitro hematopoiesis. Most progenitor cells added to irradiated cultures were no longer detectable by clonal assays within one to four days after recharge. Nonetheless, stable populations of adherent BFU-E and CFU-GM became established in these cultures within 24 to 48 hours, and when the total numbers of progenitors (adherent and nonadherent) were measured at weekly intervals thereafter, it was evident that both BFU-E and CFU-GM were generated in vitro. However, progenitor cell production declined as neutrophils and macrophages accumulated in the cultures. Moreover, with this accumulation of mature myeloid cells, increasing levels of O2- and H2O2 could be detected in the cultures, and it was found that the addition of oxidant scavengers (catalase and mannitol) to culture media enhanced the weekly expansions of progenitor cell numbers that could be measured. These findings support the conclusion that reactive O2 intermediates generated by mature myeloid cells have a role in limiting the duration and extent of hematopoietic progenitor cell self-renewal in long-term “Dexter” cultures of human marrow.
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A. H. Ramírez, O. Talavera, S. Souto, J. I. Golzarri, and G. Espinosa. "Analysis of the Radon-222 Concentration and Physical-chemical Quality, in Drinking Water of Taxco, Guerrero." Journal of Nuclear Physics, Material Sciences, Radiation and Applications 7, no. 2 (February 28, 2020): 203–7. http://dx.doi.org/10.15415/jnp.2020.72026.
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In this work the determination of radon gas (222Rn) and the characterization of chemical elements in drinking water of the city Taxco was carried out. Ingesting or inhaling a small number of radionuclides, as well as water of poor chemical quality, can become a potential public health problem. We are collecting 8 samples of water from a spring, physicochemical parameters were measured in field on different days of the dry season. Measurements of 222Rn were performed in the laboratory with an AlphaGUARD equipment. The chemical quality was analyzed in laboratory too by means of mayor and minor ions, by volumetry and colorimetry. The sodium was determined by Flama Atomic Absorption Spectroscopy (FAAS). Trace elements were analyzed by were determined by Atomic Emission Spectroscopy with Plasma Coupled by Induction (ICP-AES). The concentrations of 222Rn present an average of 22.06 ± 2.52 BqL-1. The results obtained from the main ions and field parameters show a type of diluted sodium-calcium-bicarbonate water. The trace elements present are very small and not exceed the limit of quantification. Radon gas is produced by the igneous rock that is the top of the stratigraphic column, of the hydric recharge. Rainwater when descending through the fractures is impregnated with 222Rn gas and accumulated in the underlying rock that has sufficient porosity to accumulate water and gas in the Chacualco´s spring.
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Del Toro-Guerrero, Francisco, Enrique Vivoni, Thomas Kretzschmar, Stephen Bullock Runquist, and Rogelio Vázquez-González. "Variations in Soil Water Content, Infiltration and Potential Recharge at Three Sites in a Mediterranean Mountainous Region of Baja California, Mexico." Water 10, no. 12 (December 13, 2018): 1844. http://dx.doi.org/10.3390/w10121844.
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In this research, we examined temporal variations in soil water content (θ), infiltration patterns, and potential recharge at three sites with different mountain block positions in a semiarid Mediterranean climate in Baja California, Mexico: two located on opposing aspects (south- (SFS) and north-facing slopes (NFS)) and one located in a flat valley. At each site, we measured daily θ between 0.1 and 1 m depths from May 2014 to September 2016 in four hydrological seasons: wet season (winter), dry season (summer) and two transition seasons. The temporal evolution of θ and soil water storage (SWS) shows a strong variability that is associated mainly with high precipitation (P) pulses and soil profile depth at hillslope sites. Results shows that during high-intensity P events sites with opposing aspects reveal an increase of θ at the soil–bedrock interface suggesting lateral subsurface fluxes, while vertical soil infiltration decreases noticeably, signifying the production of surface runoff. We found that the dry soil conditions are reset annually at hillslope sites, and water is not available until the next wet season. Potential recharge occurred only in the winter season with P events greater than 50 mm/month at the SFS site and greater than 120 mm/month at the NFS site, indicating that soil depth and lack of vegetation cover play a critical role in the transport water towards the soil–bedrock interface. We also calculate that, on average, around 9.5% (~34.5 mm) of the accumulated precipitation may contribute to the recharge of the aquifer at the hillslope sites. Information about θ in a mountain block is essential for describing the dynamics and movement of water into the thin soil profile and its relation to potential groundwater recharge.
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KUMAR, SATYENDRA, R. RAJU, PARVENDER SHEORAN, RAMAN SHARMA, R. K. YADAV, RANJAY K. SINGH, P. C. SHARMA, and V. P. CHAHAL. "Techno-economic evaluation of recharge structure as localized drainage option for sustainable crop production in sodic agro-ecosystems." Indian Journal of Agricultural Sciences 90, no. 1 (March 2, 2020): 212–19. http://dx.doi.org/10.56093/ijas.v90i1.98683.
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The low infiltration capacity of sodic soils and alkaline irrigation water are the main limiting factors in sustaining crop production under salt affected agro-ecosystems. The extreme rains aggravate the chances of crop failure further, due to water stagnation for prolonged period under sodic lands. Frequency of such extreme rainfall events is likely to increase in near future due to changing climatic scenario. ICAR-Central Soil Salinity Research Institute, Karnal, designed, developed and installed the cavity type individual farmers' based recharge structure at four locations in low lying areas of adopted villages (under Farmer FIRST Project) of Kaithal district for evaluating their effectiveness in facilitating the localized drainage option and sustainable crop production. The study results indicated that the installed structures were quite effective in saving the submerged crops particularly during the periods of intense rain in addition to augmenting groundwater and improving its quality. The groundwater table rose to an extent of 2-3 m beneath the structure during monsoon month (July 2017) compared to summer month of April 2017. The improvement in groundwater quality was also observed in surrounding areas as a consequence of reduction in RSC by 2-3 meq/l compared to the values at the time of installation of the structure. A heavy rainfall (~150 mm) resulted in 35-40% crop damage in open-fields which was reduced down to 5-15% due to provision of recharge structure, significantly decreasing the additional cost towards re-transplanting and compensated the yield loss. Benefit-cost ratio of 1.93 and internal rate of return of 145% indicated economic feasibility of the investment on recharge structure. The results revealed that installation of recharge structure was quite advantageous in providing the localized drainage option in low lying and land locked areas where runoff gets accumulated and adversely affected the crop production.
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MEENA, S. C., K. K. SHARMA, H. SWAMI, B. S. RANA, LEKHA LEKHA, and V. D. LOHOT. "Survey record of lac insect Kerria lacca and its host plants in western plains of India." Indian Journal of Agricultural Sciences 90, no. 1 (March 2, 2020): 220–25. http://dx.doi.org/10.56093/ijas.v90i1.98684.
Full textAbstract:
The low infiltration capacity of sodic soils and alkaline irrigation water are the main limiting factors in sustaining crop production under salt affected agro-ecosystems. The extreme rains aggravate the chances of crop failure further, due to water stagnation for prolonged period under sodic lands. Frequency of such extreme rainfall events is likely to increase in near future due to changing climatic scenario. ICAR-Central Soil Salinity Research Institute, Karnal, designed, developed and installed the cavity type individual farmer’s based recharge structure at four locations in low lying areas of adopted villages (under Farmer FIRST Project) of Kaithal district for evaluating their effectiveness in facilitating the localized drainage option and sustainable crop production. The study results indicated that the installed structures were quite effective in saving the submerged crops particularly during the periods of intense rain in addition to augmenting groundwater and improving its quality. The groundwater table rose to an extent of 2-3 m beneath the structure during monsoon month (July 2017) compared to summer month of April 2017. The improvement in groundwater quality was also observed in surrounding areas as a consequence of reduction in RSC by 2-3 meq/l compared to the values at the time of installation of the structure. A heavy rainfall (~150 mm) resulted in 35-40% crop damage in open-fields which was reduced down to 5-15% due to provision of recharge structure, significantly decreasing the additional cost towards re-transplanting and compensated the yield loss. Benefit-cost ratio of 1.93 and internal rate of return of 145% indicated economic feasibility of the investment on recharge structure. The results revealed that installation of recharge structure was quite advantageous in providing the localized drainage option in low lying and land locked areas where runoff gets accumulated and adversely affected the crop production.
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Narantsogt, Nasanbayar, and Ulf Mohrlok. "Evaluation of MAR Methods for Semi-Arid, Cold Regions." Water 11, no. 12 (December 2, 2019): 2548. http://dx.doi.org/10.3390/w11122548.
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Mongolia is a semi-arid, highly continental region with highly variable precipitation and river discharge. The groundwater aquifer located near Ulaanbaatar, the capital city of Mongolia, is the only one source for city water supply consumption, and it is important to ensure that groundwater is available now and in the future. The main watercourse near the capital city is the Tuul River, fed by precipitation in the Khentii Mountains. The semi-arid and cold environment shows high variability in precipitation and river discharge. However, due to absence of precipitation in winter and spring, the riverbed usually runs dry during these times of the year, and weather observations show that the dry period has been extending in recent years. However, in parallel with urban development, the extended groundwater aquifer has shown a clear decline, and the groundwater levels have dropped significantly. Therefore, a groundwater management system based on managed aquifer recharge is proposed, and a strategy to implement these measures in the Tuul River valley is presented in this paper. This strategy consists of the enhancement of natural recharge rates during the wet summer from the northern drainage canal, an additional increase in groundwater recharge through melting the ice storage in the dry period, as well as the construction of underground dams to accumulate groundwater and a surface water reservoir that releases a constant discharge in the outlet. To increase natural recharge rates of groundwater during the early dry period through the melting ice storage period, the MATLAB icing code, which was written for ice storage for limited and unlimited areas, was considered through finite element subsurface FLOW (FEFLOW) simulation scenarios as a water source in ice form on the surface. A study of the artificial permafrost of underground as an ice dam was processed in FEFLOW simulation scenarios for accumulating groundwater resources. The results of these artificial recharging methods were individually calculated, combined, and compared with the surface reservoir, which releases a constant discharge through the dam. In this paper, new ideas are presented involving managed aquifer recharge—MAR methods, and include application to aufeis, a mass of layered ice for groundwater recharge by melting. Additionally, the accumulation of groundwater using artificial permafrost is used as an underground dam. In addition, was considered recharging scenario only with constant release water amount from water reservoir also with all MAR methods together with reservoir combination.
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Kuipers, P. J., M. C. Ryan, and B. J. Zebarth. "Estimating nitrate loading from an intensively managed agricultural field to a shallow unconfined aquifer." Water Quality Research Journal 49, no. 1 (August 27, 2013): 10–22. http://dx.doi.org/10.2166/wqrjc.2013.136.
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Nitrate loading from an intensively managed commercial red raspberry field to groundwater in the Abbotsford-Sumas Aquifer, British Columbia was estimated over a 1 yr period and compared with the nitrogen surplus calculated using a simple nitrogen budget. Nitrate loading was estimated as the product of recharge (estimated from climate data as total precipitation minus potential evapotranspiration (PET)) and monthly nitrate concentration measured at the water table. Most nitrate loading occurred when nitrate, accumulated in the root zone over the growing season, was leached following heavy autumn rainfall events. Elevated groundwater nitrate concentrations at the water table during the growing season when recharge was assumed to be negligible suggested that the nitrate loading was underestimated. The estimate of annual nitrate loading to the water table was high (174 kg N ha−1) suggesting that the tools currently available to growers to manage N in raspberry production are not adequate to protect groundwater quality. The calculated nitrogen surplus from the nitrogen budget (180 kg N ha−1) was similar to the measured nitrate loading suggesting that simple nitrogen budgets may be relatively effective indices of the risk of nitrate loading to groundwater.
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Pinti, Daniele Luigi, Marie Larocque, Pauline Méjean, Marion Saby, Mario Alberto Hernández-Hernández, Sylvain Gagné, Emilie Roulleau, et al. "Regional-Scale Distribution of Helium Isotopes in Aquifers: How Informative Are They as Groundwater Tracers and Chronometers?" Water 14, no. 12 (June 16, 2022): 1940. http://dx.doi.org/10.3390/w14121940.
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This study presents an almost entirely unpublished dataset of 121 samples of groundwater analyzed for helium concentration and its isotopic ratio (3He/4He) in two adjacent watersheds of the St. Lawrence Lowlands, in a region with intensive agricultural activities in the southern Québec Province, Eastern Canada. Most of the samples were collected in the regional bedrock fractured aquifer hosted in mid-Ordovician siliciclastic shales, on a total surface of 7500 km2. Even with this low-density sampling, and in a heterogeneous and fractured aquifer, the helium isotopes bring precious information on the recharge conditions and on chemical evolution of water. The helium spatial interpolation does not show a clear isotopic gradient through the basin. However, it shows progressive enrichment of radiogenic 4He in the confined part of the aquifer. The atmospheric and/or tritiogenic-rich helium occurs at the recharge in the Appalachians and in the middle of the plain, where impermeable cover is limited, and local infiltration of meteoric freshwater reaches the bedrock aquifer. The relation between the total dissolved solids (TDS) and 3He/4He ratios remains elusive. However, on discriminating the samples with the dominant chemistry of water, a clear trend is observed with 3He/4He ratio, suggesting that radiogenic 4He accumulates together with dissolved solids and with increasing time (indicated by progressively older 14C ages). Finally, the noble gas temperatures (NGTs) obtained from concentrations of the other noble gases (Ne, Ar, Kr and Xe) brings constraints on the earlier recharge conditions during the Holocene. Particularly, the NGTs showed that the studied aquifers were continuously replenished, even under ice-sheet cover in the last 10,000 years.
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Villarreal, Carlos J., Richard E. Zartman, Wayne H. Hudnall, Dennis Gitz, Ken Rainwater, and Loren M. Smith. "Spatial Distribution and Morphology of Sediments in Texas Southern High Plains Playa Wetlands." Texas Water Journal 3, no. 1 (May 29, 2012): 1–13. http://dx.doi.org/10.21423/twj.v3i1.2070.
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Playas are depressional geomorphic features on the U.S. High Plains. About 20,000 Southern High Plains playa wetlandsserve as runoff catchment basins, which are thought to be focal points of Ogallala aquifer recharge. Sediments in playas can alter biodiversity services, impede aquifer recharge, and increase evaporative water losses. The purpose of this study was to evaluate the effects of watershed cultivation systems on post-cultural sediment deposition in 3 pairs of cropland/native grassland playas in Briscoe, Floyd, and Swisher counties of Texas. A hydraulic probe was used to collect soil cores to 2 m or to refusal depth at 25 possible locations in each playa. Particle size distribution and soil color effectively identified sediment additions to the playas. Soil color transitions with depth from very dark grayish brown (10YR 3/2) to very dark gray (10YR 3/1) were always found in cropland playas but not in grassland playas. Particle size distribution was more useful in identifying sediment distribution than type. Using a kriging model, sediment volume in each playa was calculated from sediment thicknesses at the sampling locations and from sediment thicknesses interpolated between sampling locations. Sediment volume was directly related to watershed land use with more accumulated sediment in cropped playas than in grassland playas. Erosion of cultivated watersheds near playas contributes sediments that decrease playa depth and can result in increased evaporative water losses and decreased aquifer recharge. Citation: Villareal CJ, Zartman RE, Hudnall WH, Gitz D, Rainwater K, Smith LM. 2012. Spatial distribution and morphology ofsediments in Texas southern high plains playa wetlands. Texas Water Journal. 3(1):1-13. Available from: https://doi.org/10.21423/twj.v3i1.2070.
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Hailekiros, Kahsay, Tesfamichael Gebreyohannes, Abdelwassie Hussein, and Hagos Brhane. "Water Balance Components Estimation using WetSpass Model: A Case study of Mekelle Area, Tigray, Ethiopia." Physical Science International Journal 27, no. 3 (August 4, 2023): 27–37. http://dx.doi.org/10.9734/psij/2023/v27i3793.
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This research was aimed at estimating the spatially distributed Water balance components of the catchments in Mekelle area by using WetSpass hydrological model and verifying the model outputs with ground truth. Long term mean metrological data and physical characteristics of the catchments were used as an input to the model. The input data were manipulated using Arc- GIS tools. Results of this model depicted that about 73.13% and 19.96% of the precipitation in the study area was lost through evapotranspiration and surface runoff respectively. However, 7% of it replenished the groundwater. The annual runoff and groundwater recharge estimated in WetSpass model accumulated using Arc-GIS were verified using the annual runoff gauged records and base flow measurements. Accordingly the accumulated runoff and base flow derived from the WetSpass model using Arc-GIS software results were quite close to the observed runoff and base flow values measured in the gauging points. Therefore, WetSpass model is appropriate model in estimating water balance components in the study area.
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Moon, Jihyun, Hoseung Lee, and Hoonyol Lee. "Elevation Change of CookE2 Subglacial Lake in East Antarctica Observed by DInSAR and Time-Segmented PSInSAR." Remote Sensing 14, no. 18 (September 15, 2022): 4616. http://dx.doi.org/10.3390/rs14184616.
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In this study, elevation change and surface morphology of CookE2, one of the most active subglacial lakes in East Antarctica, were analyzed by using Differential Interferometric Synthetic Aperture Radar (DInSAR) and a newly adapted Time-Segmented Persistent Scatterer Interferometric Synthetic Aperture Radar (TS-PSInSAR) techniques. Firstly, several DInSAR pairs were used to study the surface morphology of the subglacial lake during the rapid discharge event in 2007 and the subsequent recharge in 2010 by using ALOS PALSAR data and the continuous recharge from 2018 to 2020 by using Sentinel-1 SAR data. For time-series observation from 2018 to 2020, however, simple integration of DInSAR deviates largely from the satellite altimeter data because errors from the horizontal flow of the surrounding ice field or atmospheric phase accumulate. Conventional PSInSAR deviates from the altimeter data if the LOS displacement exceeds 300 mm, i.e., approximately 1/4 of the slant range resolution of the Sentinel-1 SAR in Interferometric Wide-swath (IW) mode, during the time window. Therefore, a series of Time-Segmented PSInSAR with a 4-month time window could accurately distinguish 1.10 ± 0.01 m/year of highly linear (R2 = 0.99) surface rise rate of CookE2 and 0.63 m/year of horizontal deformation rate of the surrounding ice field from 2018 to 2020.
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McCartney, Victoria A., Ewen Silvester, John W. Morgan, and Phillip J. Suter. "Physical and chemical drivers of vegetation in groundwater-source pools on the Bogong High Plains, Victoria." Australian Journal of Botany 61, no. 7 (2013): 566. http://dx.doi.org/10.1071/bt13217.
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The wetland communities intimately associated with groundwater sources in the Australian alps are poorly documented compared with the broader (and more obvious) alpine peatlands. In the present work, we report on the vegetation observed immediately around such sources and the characteristics of the supplying groundwater so as to understand the likely factors controlling the observed vegetation assemblage. Thirty-two groundwater sources were identified across three catchments on the Bogong High Plains, Victoria (Australia), and the vegetation associated with these sources surveyed. Groundwater sources occurred across a range of altitudes (1667–1854 m), independent of aspect, and were hydrologically connected to (upstream of) peatlands. Localised mounding adjacent to the groundwater sources resulted in the formation of pools (‘groundwater source pools’). The vegetation within the pools was dominated by bryophytes, with the aquatic bryophyte Blindia robusta the most common species. The groundwater was deficient in major ions, and similar to rainwater apart from elevated concentrations of CO2 accumulated in the groundwater-recharge process. The high CO2 concentrations, combined with the near-constant temperature conditions provided by sustained groundwater flow, are thought to be likely drivers for the high abundance of B. robusta. Although the relative contributions of rain and snow to aquifer recharge are not fully understood for the Australian Alps, these ecosystems are likely to be vulnerable to the changes in precipitation regime that are predicted under climate-change scenarios.
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Liu, Wen, Liankai Zhang, Pengyu Liu, Xiaoqun Qin, Xiaojing Shan, and Xin Yao. "FDOM Conversion in Karst Watersheds Expressed by Three-Dimensional Fluorescence Spectroscopy." Water 10, no. 10 (October 11, 2018): 1427. http://dx.doi.org/10.3390/w10101427.
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A karst system, formed by the dissolution of carbonate rocks, is usually susceptible to contamination. Little is known about the composition of natural dissolved organic matter (DOM) in groundwater systems, especially in karstic groundwater. To reveal the characteristics of DOM in a karst aquifer, the Yufuhe River Basin, a typical karst watershed in northern China, was selected. DOM fluorescence (FDOM) was measured with the excitation-emission matrices (EEMs) spectroscopy technique. Parallel factor analysis (PARAFAC) was used to analyze the karst hydrogeological factors that affect FDOM biogeochemical behavior. Three fluorescent components, i.e., tyrosine-like, tryptophan-like, and ultraviolet fulvic acid were found. Their fluorescence properties were closely related to human activity and subterranean hydrology. Fluorescence properties suggested that FDOM in the Yufuhe River karst aquifer was predominant from anthropogenic activity. In addition, due to the effect of karstic heterogeneous hydrological conditions, FDOM showed obvious differentiation in the recharge, flow path, and discharge systems. The FDOM fluorescence intensity (FI) was weak in surface water and groundwater at the upper reaches (recharge area). In the middle of the flow path area, the percentage of tyrosine-like and tryptophan-like substances degraded and fulvic acid rose gradually. However, after infiltrating into the lower reaches (discharge area) of the deep karst aquifer system, the fulvic acid matter was consumed and protein-like matter accumulated.
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Sanford, P., X. Wang, K. D. Greathead, J. H. Gladman, and J. Speijers. "Impact of Tasmanian blue gum belts and kikuyu-based pasture on sheep production and groundwater recharge in south-western Western Australia." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 755. http://dx.doi.org/10.1071/ea02226.
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The effect of Tasmanian blue gum (Eucalyptus globulus) belts and kikuyu (Pennisetum clandestinum) grass on livestock production and groundwater recharge was studied in the high rainfall zone (>600 mm/year) of south-western Western Australia from 1998 to 2001. The objective was to identify optimum combinations of tree belts and pasture for sustainable livestock production and the prevention of secondary salinisation. Treatments were annual pasture, in competition with trees at different orientations (east, west and south), kikuyu pasture in competition with trees at one orientation (west), compared with pasture in the absence of tree competition. Plots had 0, 20 or 36% of their area within 10 m of the tree belt where tree–pasture competition would be expected. Plots (0.48 ha) were stocked with Merino wether hoggets at 12 DSE/ha on annual pastures and 14 DSE/ha on kikuyu pastures. Additional sheep were placed on plots in spring and the annual pasture was destocked in autumn.Within the growing season, herbage mass was similar across both control treatments as a result of varying stock numbers. However, in summer and autumn the kikuyu control contained between 350 and 4900 kg DM/ha more herbage than the corresponding annual pasture. While both pastures accumulated similar amounts of herbage in 1998 and 2000, kikuyu accumulated more in 1999 (11 900 v. 9800 kg DM/ha) as a result of summer rain. Competition from tree belts significantly reduced adjacent annual pasture herbage accumulation (16% average reduction), although there was no difference among the levels of competition. Trees did not significantly affect adjacent kikuyu pasture herbage accumulation. Both carrying capacity and clean wool production per hectare were significantly higher on kikuyu pasture in 1999 and 2000. Tree competition also significantly reduced the carrying capacity of neighbouring annual and kikuyu pasture by an average of 10%. Clean wool production per hectare was significantly lower on annual pasture in combination with trees (11% reduction on average), but there was less effect of competition on kikuyu pasture. The kikuyu pasture used 115, 57 and 132 mm more water than the annual pasture in 1999, 2000 and 2001, respectively. The soil water deficit beneath the trees exceeded that below both control pastures by between 297 and 442 mm.Although the addition of tree belts to annual pasture provided substantial reductions in groundwater recharge, producers would also have to accept losses in livestock production. While kikuyu alone provided significant increases in livestock production and substantial reductions in groundwater recharge, the best compromise was kikuyu in combination with tree belts.
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Mazzilli, Naomi, Konstantinos Chalikakis, Simon D. Carrière, and Anatoly Legchenko. "Surface Nuclear Magnetic Resonance Monitoring Reveals Karst Unsaturated Zone Recharge Dynamics during a Rain Event." Water 12, no. 11 (November 14, 2020): 3183. http://dx.doi.org/10.3390/w12113183.
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Understanding karst unsaturated zone (UZ) recharge dynamics is crucial for achieving sustainable management of karst hydrosystems. In this paper, we provide the first report of the application of surface nuclear magnetic resonance (SNMR) monitoring of a karst UZ during a typical Mediterranean rain event. This 79 days’ SNMR monitoring is a part of a more than 2 years of SNMR monitoring at the Low Noise Underground Laboratory (LSBB) experimental site located within the Fontaine de Vaucluse karst hydrosystem (southeastern France). We present eight SNMR soundings conducted before and after the rain event that accumulated 168 mm in 5 days. The obtained results demonstrate the applicability and the efficiency of SNMR for investigating infiltration dynamics in karst UZs at the time scale of a few days. We present the SNMR amplitudes that highlight strong signal variations related to water dynamics in the karst UZ. Infiltrated water cause increased SNMR signal during 5 days after the rain event. A significant draining process of the medium starts 15 days after the main event. Finally, after 42 days, the SNMR signal returns close to the initial state.
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Liang, Xiaoyan, Liqiang Zhao, Zhenmin Niu, Xingbin Xu, Nan Meng, and Nai’ang Wang. "Warm Island Effect in the Badain Jaran Desert Lake Group Region Inferred from the Accumulated Temperature." Atmosphere 11, no. 2 (January 30, 2020): 153. http://dx.doi.org/10.3390/atmos11020153.
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The Badain Jaran Desert (BJD) is characterized by the coexistence of over 110 perennial lakes and thousands of megadunes in its southeast part. Unlike the cold island effect, we found a special phenomenon of the warm island effect in the lake group region of the BJD. However, the concept and formation mechanism remains unclear. In this study, based on observations of land surface processes in the area, we first used the daily mean temperature from 23 automated meteorological stations from 2010 to 2017 to calculate the mean daily temperature (T) ≥ 0 °C, T ≥ 10 °C accumulated temperature and negative accumulated temperature. Furthermore, using the net radiation from two eddy covariance measurement systems, characteristics of the net radiation between the lake and megadunes were analyzed. When comparing observed data in the lake group region to surrounding areas, accumulated temperature from all three meteorological stations in the lake group region were higher; the duration days of T ≥ 0 °C and T ≥ 10 °C were longer, whereas duration days of negative accumulated temperature were shorter. In addition, the initial dates for T ≥ 0 °C and T ≥ 10 °C accumulated temperature were earlier, whereas the end dates were delayed. Variations in heat were observed between stations in the lake group region that may be reflective of microclimate environments between lakes. The authors relate warm island formation in the BJD lake group region to (1) the heat carried by groundwater recharge to the desert lake groups has a great impact on the local temperature. (2) Net heat radiation to the atmosphere through sensible heat flux owing to sparse vegetation in the desert areas. Hence, heat resources are richer in the lake group region. This study aims to improve our understanding of the warm island effect from a comprehensive analysis of its intensity and distribution pattern around the lake group region as compared to its surroundings. In addition, the results from this study will provide a scientific basis for determining the source of lake water in the BJD.
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Putri, Tsamaroh Nidaa, and Priyo Sasmoko. "ALAT PEMANTAU PENGOSONGAN AKUMULATOR 12V/ 5Ah BERBASIS ARDUIONO UNO." Gema Teknologi 18, no. 4 (April 30, 2016): 10. http://dx.doi.org/10.14710/gt.v18i4.21910.
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Tsamaroh Nidaa Putri, Priyo Sasmoko explains that accumulator is a combination of several pieces of cells used for altering the chemical energy into electricity energy used in motor vehicles. Accumulators are used continuously will shrink and drop so it needs to be recharged. To know the state of the battery voltage drop experienced the need for a measurement to determine the ability of the accumulator. Design manufacture accumulator discharge monitoring tool consists of a voltage divider circuit to know the big accumulator voltage in percentage form. Used also an ACS712 current sensor to detect the discharge current and LM35 temperature sensor to determine the temperature of the accumulator. The control system used is the Arduino UNO microcontroller and an LCD for displaying the measurement data. Normal voltage ranges accumulator 12,5V - 13,8V. Accumulator with a capacity of 5Ah takes 8 hours to process discharge when using 20 watt lamp load. If the voltage of the first accumulator on the LCD shows the percentage of 0 % then automatically the system will work to discharge for a second accumulator. The duration of use depends on the large accumulator load used. Keyword:Accumulator, ACS712, capacity accumulator, Arduino UNOReferencesAgustin, Leonandi. 2015. Rancang Bangun Sistem Monitoring Kondisi Aki Pada Kendaraan Bermotor. Skripsi. Universitas Tanjungpura Pontianak.Andri, Helly. 2010. Rancang Bangun System Battery Charging Automatic. Skripsi S1 Teknik Elektro Fakultas Teknik Universitas Indonesia.Asnan, Zainal. 2007. Alat Pengecekan Kapasitas Aki (Accu) Berbasis Personal Computer. Skripsi. Universitas Katolik Widya Mandala Surabaya.Bishop, Owen. 2004. Dasar-dasar Elektronika. Jakarta: Erlangga, Alih Bahasa Irzam Harmein.Fadli, Usman. 2015. Aplikasi Sensor Arus ACS712 Dan Borland Delphi 7.0 untuk Monitoring Penggunaan Daya Listrik pada Rumah Berbasis Arduino UNO. Tugas Akhir. Universitas Diponegoro.Frank D. Petruzella., 2001, Elektronika Industri. Yogyakarta: Penerbit ANDI, Penerjemah Suminto, Drs. MA.,Kadir, Abdul. 2013. Panduan Praktis Mempelajari Aplikasi Mikrokontroler dan Pemrogamannya Menggunakan Arduino. Yogyakarta: Penerbit ANDI.Marpaung, May Harpri Rabiman. 2014. Monitoring Suhu dengan Menggunakan Sensor Suhu LM35 Serta Pengaturan Suhu Pada Otomatisasi Dispenser Berbasis Arduino UNO dengan Tampilan LCD. Tugas Akhir. Universitas Diponegoro.Salim, Emil. 2014. Perancangan dan Implementasi Telemetri Suhu Berbasis Arduino UNO, Skripsi. Universitas Sumatra Utara.Setiyawan, Danang Duwi. 2015. Pengisi Baterai Akumulator Otomatis Berbasis Mikrokontroller. Tugas Akhir. Universitas Gajah Mada.Tooley, Michael. 2003. Rangkaian Elektronik Prinsip dan Aplikasi. Jakarta: Erlangga, Alih Bahasa Irzam Harmein
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Bristow, Charlie S., Lucy Buck, and Maria Inggrid. "Four-Dimensional Investigation of Gravel Beach Ridge Accretion and 50 Years of Beach Recharge at Dungeness, UK, Using Historic Images, GPR and Lidar (HIGL)." Applied Sciences 11, no. 21 (November 1, 2021): 10219. http://dx.doi.org/10.3390/app112110219.
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Dungeness is a cuspate foreland on the south coast of England that is the largest shingle feature in Europe and includes hundreds of beach ridges. It is also the location of two nuclear power stations that were constructed in the 1960s. The dominant southwest waves cause longshore drift from west to east, eroding the southwest side of Dungeness, accompanied by accretion on the east side. A record of this eastward movement and sediment accretion is preserved by the shingle beach ridges. The power stations are located on the eroding southwestern side of the ness, and a system of beach recharge has been used to move shingle from the downdrift, east-facing shore to the updrift, southwest-facing shore to protect the power stations from coastal erosion. We use a novel combination of historic images, ground-penetrating radar (GPR), and Lidar (HIGL) to investigate accretion and beach ridges at Dungeness during the past 80 years. We report changes in accretion along the coast and use GPR to determine the thickness of beach gravels. The amount of accretion, represented by the width of the backshore, decreases downdrift from south to north. The number of beach ridges preserved also decreases from south to north. By combining the shingle thickness from GPR with elevation data from Lidar surveys and records of beach accretion measured from aerial images, we estimate the volume and mass of gravel that has accumulated at Dungeness. Historic rates of beach accretion are similar to recent rates, suggesting that the 55 years of beach recharge have had little impact on the longer-term accretion downdrift.
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Pastor, F., J. A. Valiente, and M. J. Estrela. "Sea surface temperature and torrential rains in the Valencia region: modelling the role of recharge areas." Natural Hazards and Earth System Sciences Discussions 3, no. 2 (February 12, 2015): 1357–96. http://dx.doi.org/10.5194/nhessd-3-1357-2015.
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Abstract. Heavy rain events are frequently recorded in the Western Mediterranean causing economic losses and even human casualties. The Western Mediterranean is a deep and almost closed sea surrounded by high mountain ranges and with little exchange of water with the Atlantic ocean. A main factor in the development of torrential rains are ocean-atmosphere exchanges of heat and moisture that can potentially destabilize air masses travelling over the sea. The study of air mass trajectories previous to the rain event permits the identification of sea areas that could probably contribute to the development or intensification of rainfall. From a previous Mediterranean sea surface temperature climatology, its spatio-temporal distribution patterns have been studied showing two main distribution modes in winter and summer and transitional regimes in spring and autumn. Hence, three heavy precipitation events, for such winter and summer sea temperature regimes and for fall transition, affecting the Valencia region have been selected to study the effect of sea surface temperature in torrential rains. Simulations with perturbed sea surface temperature in different areas along the air mass path were run to compare results with unperturbed simulation. The variation of sea surface temperature in certain areas caused significant changes in model accumulated values and its spatial distribution. Therefore, the existence of recharge areas where air–sea interaction favors the development of torrential rainfall in Valencia region has been shown. This methodology could be extended to the whole Mediterranean basin to look for such potential recharge areas. The identification of sea areas that contribute to the development or intensification of heavy rain events in the Mediterranean countries could be a useful prognosis and/or monitoring tool.
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Knight, A., K. Blott, M. Portelli, and C. Hignett. "Use of tree and shrub belts to control leakage in three dryland cropping environments." Australian Journal of Agricultural Research 53, no. 5 (2002): 571. http://dx.doi.org/10.1071/ar01089.
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The water extraction of deep-rooted perennial trees and shrub belts integrated with annual cropping/grazing systems was studied at 3 sites in the 300–450 mm rainfall zone of the Murray–Darling Basin of south-eastern Australia. Within 4 years of planting alley farming systems on cropland, the soil directly below and near the belts had dried the deep profile. Between 82 and 261 mm of extra soil water storage capacity was created in the 2.5 to 5.5–6 m profile. At Palamana (the only site monitored to greater depth), living roots were found 16 m below the surface. The cumulative water content of the soil to 12 m under the belts was 600 mm less than of soil cores extracted from nearby cropland. This water storage difference created under the belts is greater than the largest episodic event likely in this region and it is therefore unlikely that leakage will occur directly under or within a few metres of the belts. The early growth of the belts was rapid and the leaf area of the belts far exceeded that of remnant mallee eucalypt vegetation. The belts used water that had accumulated deep in the profile below the annual cropping systems they replaced. However, the belts only used water from below or within a few metres from the edge with the adjacent cropland. As suggested by RJ Harper et al. (2000), a much greater amount of potential recharge could be controlled if deep-rooted perennials were planted more closely across the landscape (compared with widely spaced belts). However, although the belts may be beneficial for the catchment water balance, they would be commercially unacceptable to farmers. In practice, farmers put the belts usually no less than 50–70 m apart so that less cropland is displaced and there is less belt/crop competition. In such cases alley farming only controls a small percentage of the total leakage, similar to the amount of crop yield lost by displacement and competition. It would be better to use a full coverage of perennials on soils where annual systems are the leakiest, rather than belts across all of the landscape, some of which may not be very leaky and could be highly profitable for annual cropping. Leakage could be controlled under cropland in a few years by growing easy to establish perennial species to retrieve moisture deep in the profile. At Pallamana the belts utilised 600 mm of accumulated leakage from deep in the profile in less than 4 years. Based on the average annual recharge rates under annual cropping (11–35 mm) the land could be cropped again for between 17 and 55 years before that leakage accumulated again.
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Wang, Changshu, Jingwei Wu, Wenzhi Zeng, Yan Zhu, and Jiesheng Huang. "Five-Year Experimental Study on Effectiveness and Sustainability of a Dry Drainage System for Controlling Soil Salinity." Water 11, no. 1 (January 10, 2019): 111. http://dx.doi.org/10.3390/w11010111.
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The dry drainage system (DDS) is an alternative technique for controlling salinization. To quantify its role in soil salinity control, a five-year field observation from 2007 to 2011 was completed in a 2900 ha experimental plot in Yonglian Experimental Station, Hetao Irrigation District, China. Results showed that the groundwater table depth in the fallow areas quickly responded to the lateral recharge from the surrounding croplands during irrigation events. The groundwater electrical conductivity (GEC) of fallow areas increased from 5 mS·cm−1 to 15 mS·cm−1, whereas the GEC below croplands produced small fluctuations. The analysis of water and salt balance showed that the excess water that moved to fallow was roughly four times that moved by an artificial drainage system and with 7.7 times the corresponding salt. The fallow areas act as a drainage repository to receive excess water and salt from surrounding irrigated croplands. Slight salt accumulation occurred in irrigated croplands and salts accumulated, with an accelerating trend over the final two years. The evaporation capability weakened, partly due to the salt crust in the topsoil, and the decrease in soil permeability in the soil column, which was almost impermeable to water. Using halophytes may be an effective method to remove salts that have accumulated in fallow areas, having great economic and ecological value. A DDS may be effective and sustainable in situations where the fallow areas can sustain an upward capillary flux from planted halophytes.
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Pastor, F., J. A. Valiente, and M. J. Estrela. "Sea surface temperature and torrential rains in the Valencia region: modelling the role of recharge areas." Natural Hazards and Earth System Sciences 15, no. 7 (July 31, 2015): 1677–93. http://dx.doi.org/10.5194/nhess-15-1677-2015.
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Abstract. Heavy rain events are frequently recorded in the Western Mediterranean causing economic losses and even human casualties. The Western Mediterranean is a deep and almost closed sea surrounded by high mountain ranges and with little exchange of water with the Atlantic ocean. A main factor in the development of torrential rains is ocean-atmosphere exchanges of heat and moisture that can potentially destabilize air masses travelling over the sea. The study of air mass trajectories previous to the rain event permits the identification of sea areas that could probably contribute to the development or intensification of rainfall. From a previous Mediterranean sea surface temperature climatology, its spatio-temporal distribution patterns have been studied showing two main distribution modes in winter and summer and transitional regimes in spring and autumn. Hence, three heavy precipitation events, for such winter and summer sea temperature regimes and for fall transition, affecting the Valencia region have been selected to study the effect of sea surface temperature in torrential rains. Simulations with perturbed sea surface temperature in different areas along the air mass path were run to compare results with unperturbed simulation. The variation of sea surface temperature in certain areas caused significant changes in model accumulated values and its spatial distribution. Therefore, the existence of areas that at a greater extent favour air-sea interaction leading to the development of torrential rainfall in the Valencia region has been shown. This methodology could be extended to the whole Mediterranean basin to look for such potential recharge areas. The identification of sea areas that contribute to the development or intensification of heavy rain events in the Mediterranean countries could be a useful prognosis and/or monitoring tool.
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Patekar, Matko, Mihaela Bašić, Marco Pola, Ivan Kosović, Josip Terzić, Alessio Lucca, Silvia Mittempergher, Luigi Riccardo Berio, and Staša Borović. "Multidisciplinary investigations of a karst reservoir for managed aquifer recharge applications on the island of Vis (Croatia)." Acque Sotterranee - Italian Journal of Groundwater 11, no. 1 (March 31, 2022): 37–48. http://dx.doi.org/10.7343/as-2022-557.
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Managed aquifer recharge (MAR) refers to a suite of methods by which excess surface water or non-conventional water is stored underground for subsequent recovery or environmental purposes. MAR solutions have been largely used in unconsolidated aquifers, while their application in karst aquifers is rare. This research presents the first results of a MAR viability study on the island of Vis, a small karstic island in the Adriatic Sea. Favorable geological and hydrogeological conditions enable the formation of karst aquifers, making the island autonomous in terms of water supply. The island’s main aquifer, exploited in the Korita well field, is protected from seawater intrusion by several hydrogeological barriers. However, climate change and high seasonal pressures related to tourism pose a threat to the future availability of freshwater. Multidisciplinary field and laboratory investigations were carried out to detail the geological and hydrogeological setting of the island and its groundwater resource. Field analyses consisted of groundwater monitoring and sampling, geophysical investigations (i.e., electrical resistivity tomography), and structural measurements. Laboratory analyses included measurements of principal cations and anions and tritium activity. Despite low precipitation during the observation period (September 2019 - December 2020), the groundwater resource at the Korita site showed stable trends of physico-chemical parameters with a good storage potential and a long-term reserve. Geophysical investigations evidenced a relatively homogeneous sequence of the rock mass at a larger scale, while structural analyses indicated the occurrence of E-W karstified and open fractures that could represent a preferential flow path in the carbonate aquifer. A MAR solution for the Vis island was proposed combining an infiltration pond scheme with the direct injection of the accumulated waters into the aquifer using available wells. The potential water source could be represented by the runoff collected in an old artificial channel and the associated pond system in Korita.
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Masters, D., N. Edwards, M. Sillence, A. Avery, D. Revell, M. Friend, P. Sanford, G. Saul, C. Beverly, and J. Young. "The role of livestock in the management of dryland salinity." Australian Journal of Experimental Agriculture 46, no. 7 (2006): 733. http://dx.doi.org/10.1071/ea06017.
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Management of dryland salinity in Australia will require changes in the design and utilisation of plant systems in agriculture. These changes will provide new opportunities for livestock agriculture. In areas already affected by salt, a range of plants can be grown from high feeding value legumes with moderate salt tolerance through to highly salt tolerant shrubs. A hectare of these plants may support between 500 and 2000 sheep grazing days per year. The type of plants that can be grown and the subsequent animal production potential depend on a range of factors that contribute to the ‘salinity stress index’ of a site, including soil and groundwater salinity, the extent and duration of waterlogging and inundation, the pattern and quantity of annual rainfall, soil texture and chemistry, site topography and other site parameters. Where the salinity stress index is high, plant options will usually include a halophytic shrub that accumulates salt. High salt intakes by grazing ruminants depress feed intake and production. Where high and low salt feeds are available together, ruminants will endeavour to select a diet that optimises the overall feeding value of the ingested diet. In areas that are not yet salt affected but contribute to groundwater recharge, perennial pasture species offer an opportunity for improved water and salt management both on-farm and at the catchments. If perennial pasture systems are to be adopted on a broad scale, they will need to be more profitable than current annual systems. In the high rainfall zones in Victoria and Western Australia, integrated bioeconomic and hydrological modelling indicates that selection of perennial pasture plants to match requirements of a highly productive livestock system significantly improves farm profit and reduces groundwater recharge. In the low to medium rainfall zones, fewer perennial plant options are available. However, studies aiming to use a palette of plant species that collectively provide resilience to the environment while maintaining profitable livestock production may also lead to new options for livestock in the traditional cropping zone.
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Hung, Chih-Ying, Jian-Hong Yu, Liang-Wei Su, Jun-Yen Uan, Yin-Chia Chen, and Dan-Jae Lin. "Shear Bonding Strength and Thermal Cycling Effect of Fluoride Releasable/Rechargeable Orthodontic Adhesive Resins Containing LiAl-F Layered Double Hydroxide (LDH) Filler." Materials 12, no. 19 (September 30, 2019): 3204. http://dx.doi.org/10.3390/ma12193204.
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This study aims to investigate the shear bonding strength (SBS) and thermal cycling effect of orthodontic brackets bonded with fluoride release/rechargeable LiAl-F layered double hydroxide (LDH-F) contained dental orthodontic resin. 3% and 5% of LDH-F nanopowder were gently mixed to commercial resin-based adhesives Orthomite LC (LC, LC3, LC5) and Transbond XT (XT, XT3). A fluoroaluminosilicate modified resin adhesive Transbond color change (TC) was selected as a positive control. Fifteen brackets each group were bonded to bovine enamel and the SBS was tested with/without thermal cycling. The adhesive remnant index (ARI) was evaluated at 20× magnification. The fluoride-releasing/rechargeability and cytocompatibility were also evaluated. The SBS of LC, LC3, and LC5 were significantly higher than XT and TC. After thermal cycling, the SBS of LC, LC3, and LC5 did not decrease and was significantly higher than TC. The changes of ARI scores indicate that failure occurred not only cohesive but also semi-cohesive fracture. The 30 days accumulated daily fluoride release of LC3, LC5, and TC without recharge are higher than 300 μg/cm2. The LDH-F contained resin adhesive possesses higher SBS compared to positive control TC. Fluoride release and the rechargeable feature can be achieved for preventing enamel demineralization without cytotoxicity.
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Zevgolis, Ioannis E., Alexandros I. Theocharis, Alexandros V. Deliveris, and Nikolaos C. Koukouzas. "Numerical Analysis of Groundwater Effects on the Stability of an Abandoned Shallow Underground Coal Mine." Sustainability 15, no. 1 (December 28, 2022): 529. http://dx.doi.org/10.3390/su15010529.
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This work systematically quantifies groundwater’s effect on the roof stability of underground openings in shallow coal mines and indirectly assesses the potential for sinkhole formation. A specific stratigraphy was analyzed where the opening instability can lead to sinkhole formation, given the geological conditions, the overburden stratigraphy, and the depth of the openings. The groundwater recharge was investigated as an individual rainfall infiltration (short-term) and as groundwater dynamics (long-term), representing the accumulation of infiltrated rainwater with time. In the latter case, two approaches were employed for the porewater pressure calculation: (a) phreatic line with hydrostatic conditions and (b) steady-state flow based on constant groundwater head on the vertical boundaries at the model’s edges. The safety analysis was based on a simplified statics model relating the stability to the bending of the roof, and numerical analysis was employed for the stress analysis. The short-term safety remained unaffected as rainfall water accumulated on the aquitard to form perched water. The long-term safety deteriorated due to the increase of the tensile stresses in the roof of the underground openings with the rise of the groundwater table. The phreatic line approach is the most conservative, resulting in lower safety than steady-state flow.
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Wendt, Kathleen A., Mathieu Pythoud, Gina E. Moseley, Yuri V. Dublyansky, R. Lawrence Edwards, and Christoph Spötl. "Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y." GSA Bulletin 132, no. 3-4 (July 25, 2019): 793–802. http://dx.doi.org/10.1130/b35168.1.
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Abstract Subaqueous calcite deposited on the walls of Devils Hole 2 cave (Nevada, USA) represents a unique archive for geochemical variations within the regional aquifer. Here, we present a 475,000-year record of initial 234U/238U activity ratios in delta notation (δ234U0). Results show a range in values from 1851–1616‰. Variations in δ234U0 coincide with interglacial-glacial cycles over the past 475,000 years. Maximum δ234U0 values correspond to the last five glacial intervals, during which southwest Nevada experienced cool, pluvial conditions. Minimum δ234U0 values correspond to interglacial intervals, during which this region experienced warm, arid conditions. We propose that an elevated water table during glacial periods inundated previously dry bedrock and basin sediments, thereby leaching excess 234U accumulated in these materials. We interpret Devils Hole 2 cave δ234U0 as a proxy for water-rock interactions in this regional aquifer, which is ultimately tied to the surface moisture conditions at recharge zones. The mechanism proposed here serves as a testable hypothesis and possible analogue for future subaqueous speleothem studies in similar hydrogeologic settings. Due to its unprecedented duration, the Devils Hole 2 cave δ234U0 record provides the first paleo-moisture record in southwest Nevada for marine isotope stages 10–12. In addition, high-precision δ234U measurements of modern groundwaters sampled from Devils Hole 2 cave are presented.
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Nicholson, Barbara J. "Peat chemistry of a continental mire complex in western Canada." Canadian Journal of Botany 67, no. 3 (March 1, 1989): 763–75. http://dx.doi.org/10.1139/b89-103.
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A continental peatland complex in western Canada containing varied vegetational landforms was studied to relate surface physiognomy to peatland development. Peat chemistry was used to determine the influence of water chemistry on landform formation and to assess the development of ombrotrophy on forested Sphagnum islands. Surface water chemistry at the site showed the following: pH 3.7–6.3; calcium content 0.9–15.6 mg/L; magnesium content 0.5–2.8 mg/L; and reduced conductivity 0–232 μS/cm. Peat cores were subdivided into two peat types, fen and forested Sphagnum islands. Spearman rank correlations and the Mann–Whitney U-test were used to determine significant differences in ash, bulk density, calcium, and magnesium. Elemental contents of surface peats are directly related to landform features. Elemental peat profiles exhibit three accumulation trends: stable, increasing, and declining. Fen peats have profiles that are stable or increase towards the peat surface, whereas forested Sphagnum island peats have profiles that decline toward the peat surface. During the development of the mire, fen peats receiving mineral-enriched waters have accumulated higher amounts of mineral ions. Forested Sphagnum islands have developed in hydrologically sheltered areas, resulting in the formation of mineral-poor peat. Surface water, vegetation, and peat stratigraphy suggest that the forested Sphagnum islands have become ombrotrophic, forming local recharge zones with a gradual transition from a mineral-poor environment to ombrotrophy.
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Sadeghi, Morteza, Ardeshir Ebtehaj, Wade T. Crow, Lun Gao, Adam J. Purdy, Joshua B. Fisher, Scott B. Jones, Ebrahim Babaeian, and Markus Tuller. "Global Estimates of Land Surface Water Fluxes from SMOS and SMAP Satellite Soil Moisture Data." Journal of Hydrometeorology 21, no. 2 (February 2020): 241–53. http://dx.doi.org/10.1175/jhm-d-19-0150.1.
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AbstractIn-depth knowledge about the global patterns and dynamics of land surface net water flux (NWF) is essential for quantification of depletion and recharge of groundwater resources. Net water flux cannot be directly measured, and its estimates as a residual of individual surface flux components often suffer from mass conservation errors due to accumulated systematic biases of individual fluxes. Here, for the first time, we provide direct estimates of global NWF based on near-surface satellite soil moisture retrievals from the Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites. We apply a recently developed analytical model derived via inversion of the linearized Richards’ equation. The model is parsimonious, yet yields unbiased estimates of long-term cumulative NWF that is generally well correlated with the terrestrial water storage anomaly from the Gravity Recovery and Climate Experiment (GRACE) satellite. In addition, in conjunction with precipitation and evapotranspiration retrievals, the resultant NWF estimates provide a new means for retrieving global infiltration and runoff from satellite observations. However, the efficacy of the proposed approach over densely vegetated regions is questionable, due to the uncertainty of the satellite soil moisture retrievals and the lack of explicit parameterization of transpiration by deeply rooted plants in the proposed model. Future research is needed to advance this modeling paradigm to explicitly account for plant transpiration.
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Grigoryev, A. V., A. Yu Vasil’Yev, and S. M. Malyshev. "CALCULATION OF SHORT-CIRCUIT CURRENTS IN MARINE ELECTRIC POWER SYSTEMS WITH DIRECT CURRENT POWER DISTRIBUTION." Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 14, no. 2 (June 28, 2022): 296–305. http://dx.doi.org/10.21821/2309-5180-2022-14-2-296-305.
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A method for calculating shock short-circuit currents in marine electric power systems with direct current distribution of electricity is presented in the paper. These systems are widely used in shipbuilding. The calculation of short-circuit currents in such systems has a number of features related to the operating modes of these networks. In the systems with direct current electricity distribution, the generation and consumption of electricity is carried out on alternating current, while the distribution is carried out on direct current. The current standards for calculating short-circuit currents in DC and AC systems in this case cannot be used for a number of reasons. These standards do not consider specific supply sources of short-circuit points (short circuit) and variable rotational speed of valve generators in the various operating modes. AC electric motors (ED), when they are mains powered with DC power distribution via autonomous inverters, supply the short-circuit point on the DC side. Capacitor banks and accumulator batteries connected to a system with direct current electricity distribution are additional sources for the short circuit site supply. The elements of a methodology for calculating short-circuit currents in marine power plants with direct current electricity distribution, taking into account all operating modes and additional sources of short-circuit location recharge, are proposed in the paper. A method for determining the maximum value of the shock current at the short circuit design point of the ship’s electric power system is proposed.
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Villanueva-Díaz, José, Arian Correa-Díaz, Luis Ubaldo Castruita-Esparza, Jesús Valentín Gutiérrez-García, Aldo Rafael Martínez-Sifuentes, and Fátima del Rocío Reyes-Camarillo. "Tree Rings as Proxies of Historical Runoff in a National Park in Northern Mexico: A Major Ecosystem Service Provider." Atmosphere 14, no. 8 (July 26, 2023): 1199. http://dx.doi.org/10.3390/atmos14081199.
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A dendrochronological network of conifers (Pinus leiophylla, Pinus cembroides, Pinus engelmannii) was developed in the Cumbres de Majalca National Park (CMNP) in Chihuahua, Mexico, to reconstruct historical runoff patterns and examine the impact of ocean–atmosphere phenomena. The CMNP plays a vital role as a runoff source for Conchos River tributaries and groundwater recharge for Chihuahua City and nearby populations. The ring-width chronologies displayed a common signal from 1859 to 2021, with the highest association found between P. engelmannii and P. leiophylla (r = 0.65) and the lowest between P. cembroides and P. engelmannii (r = 0.55). The first principal component explained 75.7% of the variance, and among the species, P. leiophylla exhibited the highest correlation (0.624, p < 0.05) with the accumulated streamflow records from the previous November to July, allowing the construction of a bootstrapped model for runoff reconstruction. The reconstructed streamflow spanned from 1859 to 2014, with an average of 2.732 × 108 m3. Periods of low runoff occurred in 1860–1880, 1940–1960, and 1994–2014, while extreme wet years with high runoff occurred in 1865, 1884, and 1987. The interannual streamflow variability correlated significantly with ENSO indices (SOI, MEI, TRI, and sea surface temperature anomalies), particularly during the winter–spring seasons, indicating that warm phases of the ENSO increased precipitation and runoff. The analysis of return periods revealed probabilities for specific runoff volumes, enabling stakeholders to use the information to develop effective strategies for sustainable water allocation and utilization in the region.
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Servettaz, Aymeric P. M., Cécile Agosta, Christoph Kittel, and Anaïs J. Orsi. "Control of the temperature signal in Antarctic proxies by snowfall dynamics." Cryosphere 17, no. 12 (December 18, 2023): 5373–89. http://dx.doi.org/10.5194/tc-17-5373-2023.
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Abstract. Antarctica, the coldest and driest continent, is home to the largest ice sheet, whose mass is predominantly recharged by snowfall. A common feature of polar regions is the warming associated with snowfall, as moist oceanic air and cloud cover increase the surface temperature. Consequently, snow that accumulates on the ice sheet is deposited under unusually warm conditions. Here we use a polar-oriented regional atmospheric model to study the statistical difference between average and snowfall-weighted temperatures. During snowfall, the warm anomaly scales with snowfall amount, with the strongest sensitivity occurring at low-accumulation sites. Heavier snowfall in winter helps to decrease the annual snowfall-weighted temperature, but this effect is overwritten by the event-scale warming associated with precipitating atmospheric systems, which particularly contrast with the extremely cold conditions that occur in winter. Consequently, the seasonal range of snowfall-weighted temperature is reduced by 20 %. On the other hand, the annual snowfall-weighted temperature shows 80 % more interannual variability than the annual temperature due to the irregularity of snowfall occurrence and its associated temperature anomaly. Disturbances of the apparent annual temperature cycle and interannual variability have important consequences for the interpretation of water isotopes in precipitation, which are deposited with snowfall and commonly used for paleotemperature reconstructions from ice cores.
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Rempe, Daniella M., and William E. Dietrich. "Direct observations of rock moisture, a hidden component of the hydrologic cycle." Proceedings of the National Academy of Sciences 115, no. 11 (February 28, 2018): 2664–69. http://dx.doi.org/10.1073/pnas.1800141115.
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Recent theory and field observations suggest that a systematically varying weathering zone, that can be tens of meters thick, commonly develops in the bedrock underlying hillslopes. Weathering turns otherwise poorly conductive bedrock into a dynamic water storage reservoir. Infiltrating precipitation typically will pass through unsaturated weathered bedrock before reaching groundwater and running off to streams. This invisible and difficult to access unsaturated zone is virtually unexplored compared with the surface soil mantle. We have proposed the term “rock moisture” to describe the exchangeable water stored in the unsaturated zone in weathered bedrock, purposely choosing a term parallel to, but distinct from, soil moisture, because weathered bedrock is a distinctly different material that is distributed across landscapes independently of soil thickness. Here, we report a multiyear intensive campaign of quantifying rock moisture across a hillslope underlain by a thick weathered bedrock zone using repeat neutron probe measurements in a suite of boreholes. Rock moisture storage accumulates in the wet season, reaches a characteristic upper value, and rapidly passes any additional rainfall downward to groundwater. Hence, rock moisture storage mediates the initiation and magnitude of recharge and runoff. In the dry season, rock moisture storage is gradually depleted by trees for transpiration, leading to a common lower value at the end of the dry season. Up to 27% of the annual rainfall is seasonally stored as rock moisture. Significant rock moisture storage is likely common, and yet it is missing from hydrologic and land-surface models used to predict regional and global climate.
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Samedov, Pirverdi, Beyli Aliyeva, Vafa Mammadzade, Mehbara Sadigova, Matanat Aliyeva, Shahla Jafarova, and Afaq Rzayeva. "Biological Indicators and Their Significance in the Diagnosis of Alluvial-Meadow Soils." Natural Systems and Resources, no. 3 (October 2023): 42–48. http://dx.doi.org/10.15688/nsr.jvolsu.2023.3.6.
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The priority issue that is covered in the article is the expediency of using biological indicators in the diagnosis of alluvial-meadow soils. In Azerbaijan, floodplain soils, common on terraces and alluvial fans of large rivers, where there are groundwater recharge conditions and the influence of the flood floodplain regime, have been widely studied. Alluvial-meadow soils develop under the meadow soil with forb-cereal groups and shrub vegetation under the active influence of groundwater occurring at a depth of 1.0–3.5 and surface (flood) moisture. Rich herbaceous vegetation causes the development of the sod process; as a result, a large amount of organic matter accumulates. Considering that various subtypes of floodplain soils are formed, under characteristic bioclimatic conditions, our goal was to study some biological indicators of alluvial-meadow soils of natural and cultivated cenoses. On the selected biotopes (virgin cenosis, near-terrass biotope, alluvial deposits of Shin-chai, as well as agrocenoses of cereals and tobacco), the group composition and amount of microbiota, complexes of invertebrates, phytomass and humus content were comparatively studied. The accounting of phytomass on the virgin cenosis showed that plant products amount to 363 g/m2 of raw and 26 g/m2 of dry mass. Possible relationships between individual biological and some physico-chemical parameters are considered. The results obtained can be used as biotests in the diagnosis of alluvial-meadow soils. Plants are the primary source of organic residues in the soil, their main function of which as a soil-forming plant is to create primary bioproducts and participate in the global biological cycle.
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Kolev, Sava, and Mila Trayanova. "Geological and geomorphological conditions of Archar-Orsoya lowland as a factor for the formation of groundwater chemical composition and in risk of its contamination." Engineering Geology and Hydrogeology 35, no. 1 (December 2021): 63–70. http://dx.doi.org/10.52321/igh.35.1.63.
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The Archar-Orsoya lowland is situated in the Danube floodplain west of the town of Lom, NW Bulgaria. It is aligned in a west-east direction along the Danube River and to the south it is bounded by a high landslide slope, built of Pliocene clays and sands. Parallel to the shore, sand dunes are formed with lowered sections between them, in which there are conditions for swamping. The lowland is made up of the alluvial sediments of the Danube, represented by a lower gravelly-sandy layer and an upper sandy-clayey layer. In the gravelly-sandy layer unconfined groundwater is accumulated, with shallow water table – from 0.5 to 7 m beneath the surface. Groundwater is recharged by infiltration of precipitation, surface water and groundwater, which laterally flows into the alluvium from adjacent aquifers. At high waters, the Danube River suppresses the formed groundwater flow and temporarily feeds it. Due to the described formation conditions in the lowland, the chemical composition of groundwater is formed under the influence of intense dynamics and has a low TDS (total dissolved solids). The shallow groundwater table and the corresponding thin unsaturated zone are a prerequisite for easy groundwater contamination with components entering from the surface. Therefore, a map of depth to groundwater table is drawn to identify the most vulnerable areas.
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Toshisuke, Maruyama, Yoshida Masashi, Takase Keiji, Takimoto Hiroshi, and Noto Fumikazu. "Assessment of Nitrogen Pollution Load Potential for Groundwater by Mass Balance in the Tedori River Alluvial Fan Areas, Japan." Sustainable Agriculture Research 2, no. 1 (October 28, 2012): 76. http://dx.doi.org/10.5539/sar.v2n1p76.
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<p>To assess the nitrogen pollution load potential (NPLP) of groundwater, mass balance over a recent five-year period (2006–2010) was analyzed within the Tedori River alluvial fan area, Ishikawa Prefecture, Japan. All components of the hydrologic cycle in polluted regions of the study area were analyzed based on water and nitrogen balance. The water balance model was based on the exchange of river water between the channel/soil surface and the aquifer horizon fractions. The water balance calculation was conducted by considering precipitation, evapotranspiration, direct runoff, and infiltration in the channel/soil horizon (Figure 2). In addition, infiltration from paddy and other land uses, recharge and effluent from the Tedori River and pumping from the wells in the aquifer horizon were considered. Based on the water balance analysis, nitrogen balance analysis was conducted. The results revealed that the nitrogen input was 1,214.2 ton/year, while nitrogen output was 959.4 ton/year. Therefore, 254.6 ton/year accumulated within the study area. In the aquifer horizon, the amount of nitrogen deposited was found to be 232.9 ton/year. The total nitrogen concentration of water samples collected from a well with a depth of 50 m was about 1.0 mg/L, which was greater than that observed for the well of 150 m depth (about 0.25 mg/L). These findings indicate that contaminating nitrogen gradually percolates into the deeper zone. The most dominant nitrogen pollutant for the study area originated from farmland (30.5%) and second is intake water (24.2%) and third is precipitation (23.8%). These three items occupied 78.5% of total pollutant.</p>