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1
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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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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Kuncoro, C. Bambang Dwi, Min-Feng Sung, Cornelia Adristi, Arvanida Feizal Permana, and Yean-Der Kuan. "Prospective Powering Strategy Development for Intelligent-Tire Sensor Power Charger Application." Electronics 10, no. 12 (June 14, 2021): 1424. http://dx.doi.org/10.3390/electronics10121424.
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Tire sensors embedded in a vehicle tire are stand-alone autonomous devices. A tire sensor reserve power strategy is crucial due to sensor energy sources limitations for long operational periods. This paper presents an innovative tire sensor powering strategy for the intelligent-tire system. The powering strategy offers a green concept, maintenance-free, and low-cost method in order to extend the tire sensor lifetime for long operating periods. The proposed strategy adopts wireless power transfer (WPT) technology to transfer power to an electrical load mounted on the rotational system without an interconnection cable. It is composed of a power transmitter designed to be mounted on the vehicle’s inner fender liner, and a power receiver that provides power to recharge the tire sensor battery/energy storage. The transmitter transfers power from the vehicle battery/accumulator to a power receiver coupled with the tire sensor which is mounted on the vehicle tire inner wall. WPT devices were designed based on induction electromagnetic coupling and can provide an output current up to 1A at 5 V. The proposed powering strategy was verified using a vehicle tire simulator model to emulate rotational motion. A voltage and current sensor module as well microcontroller and data logger modules were utilized as the load for the developed WPT system. The verification experimental and preliminary test results reveal that the proposed strategy can provide constant power to the load (in this case, the voltage is around 4.3 V and the current is around 21.1 mA) although the vehicle tire model was rotated at different speeds from 0 rpm to 800 rpm. The proposed system has the potential and feasibility for implementation in tire sensor power applications in the intelligent-tire system.
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Karlović, Igor, Tamara Marković, and Tatjana Vujnović. "Groundwater Recharge Assessment Using Multi Component Analysis: Case Study at the NW Edge of the Varaždin Alluvial Aquifer, Croatia." Water 14, no. 1 (December 24, 2021): 42. http://dx.doi.org/10.3390/w14010042.
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Exploring the interaction between precipitation, surface water, and groundwater has been a key subject of many studies dealing with water quality management. The Varaždin aquifer is an example of an area where high nitrate content in groundwater raised public concern, so it is important to understand the aquifer recharge for proper management and preservation of groundwater quality. The NW part of the Varaždin aquifer has been selected for study area, as precipitation, Drava River, accumulation lake, and groundwater interact in this area. In this study, groundwater and surface water levels, water temperature, water isotopes (2H and 18O), and chloride (Cl−) were monitored in precipitation, surface water, and groundwater during the four-year period to estimate groundwater recharge. Head contour maps were constructed based on the groundwater and surface water levels. The results show that aquifer is recharged from both Drava River and accumulation lake for all hydrological conditions–low, mean, and high groundwater levels. The monitoring results of water temperature, chloride content, and stable water isotopes were used as tracers, i.e. as an input to the mixing model for estimation of the contribution ratio from each recharge source. The calculation of mixing proportions showed that surface water is a key mechanism of groundwater recharge in the study area, with a contribution ratio ranging from 55% to 100% depending on the proximity of the observation well to surface water.
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Holland, K. L., S. D. Tyerman, L. J. Mensforth, and G. R. Walker. "Tree water sources over shallow, saline groundwater in the lower River Murray, south-eastern Australia: implications for groundwater recharge mechanisms." Australian Journal of Botany 54, no. 2 (2006): 193. http://dx.doi.org/10.1071/bt05019.
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The decline of riparian vegetation in the lower River Murray, south-eastern Australia, is associated with a reduction in flooding frequency, extent and duration, and increased salt accumulation. The plant water sources of healthy Eucalyptus largiflorens trees growing over highly saline (>40 dS m–1) groundwater were investigated during summer when water deficit is greatest. The study found low-salinity soil water overlying highly saline groundwater at most sites. This deep soil water, rather than the saline groundwater, was identified as the plant water source at most sites. Stable isotopes of water and water potential measurements were used to infer how the deep soil water was recharged. The low-salinity, deep soil water was recharged in the following two ways: (1) vertically through the soil profile or via preferential flow paths by rainfall or flood waters or (2) horizontally by bank recharge from surface water on top of the saline groundwater. Vertical infiltration of rainfall and floodwaters through cracking clays was important for trees growing in small depressions, whereas infiltration of rainfall through sandy soils was important for trees growing at the break of slope. Bank recharge was important for trees growing within ∼50 m of permanent and ephemeral water bodies. The study has provided a better understanding of the spatial patterns of recharge at a scale relevant to riparian vegetation. This understanding is important for the management of floodplain vegetation growing in a saline, semi-arid environment.
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Vanderzalm, J. L., P. J. Dillon, G. J. Hancock, C. Leslie, J. Dighton, C. Smith, and G. Pearce. "Using elemental profiles in the sediment of a lake used to supply drinking water to understand the impacts of urban stormwater recharge." Marine and Freshwater Research 64, no. 6 (2013): 493. http://dx.doi.org/10.1071/mf12215.
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The regional city of Mount Gambier, South Australia, recharges stormwater directly into the underlying unconfined, karstic Gambier Limestone aquifer. This aquifer provides the majority of recharge to Blue Lake, a groundwater-fed volcanic crater lake, used for Mount Gambier’s drinking water supply. However, concern remains regarding the risk posed by contaminants within stormwater, in particular when stormwater recharge may ultimately contribute to a source of drinking-water supply. The present research examined the role of the annual calcite precipitation in the lake, in protecting the quality of its water supply, by examining the composition of particulate matter in the lake and on the lake bottom. The sediment did not reveal negative impacts of stormwater recharge, but did highlight the increase in erosion as a result of settlement and extensive land clearing for agriculture at the time of settlement. Analysis of lake-floor sediment revealed increased accumulation of the lithogenic elements within the lake-floor sediment during this interval, owing to the cleansing capacity of the calcite precipitation cycle. Extraction of water from Blue Lake for water supply has resulted in a reduced water residence time in the lake and a three-fold increase in the accumulation of calcium carbonate on the lake floor.
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Zhang, Zichen, Lihua Wu, Jun Feng, Zhiwen Dong, Xiong Zhao, Yi Sun, Xiping Cheng, Liqin Dong, and Tingting Liu. "Characteristics of Runoff Components in the Mingyong Glacier Basin, Meili Snow Mountains." Water 16, no. 7 (March 24, 2024): 937. http://dx.doi.org/10.3390/w16070937.
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As an important hydrological ecosystem component, the glacier basin has great significance for climate and environment, and it is also linked to regional water sustainability. In this paper, the sampling and isotope analysis of glacial ice, ice-melt water, river water (river midstream and river downstream), groundwater (spring), and precipitation were carried out in a hydrological year of the Mingyong Glacier basin, which is located at the Meili Snow Mountains, Southeastern Tibetan Plateau. At the same time, the hydrograph separation of the recharge sources of the lower mountain pass is studied. The results show that the range of δD, δ18O, and d-excess (deuterium excess) in natural water bodies are significantly different, and the precipitation is the most obvious. The high values of δD and δ18O in the water samples all appeared in spring and summer, and the low values appeared in autumn and winter, while glacial ice showed opposite trends. Meanwhile, the local meteoric water line (LMWL) of the Mingyong Glacier basin is δD = 8.04δ18O + 13.06. The End-Member Mixing Analysis (EMMA) was adopted to determine the sources proportion of river water (river downstream) according to the δD, δ18O, and d-excess ratio relationships. The results showed that the proportion of ice-melt water, groundwater, and precipitation in the ablation period was 80.6%, 17.2%, and 2.2% as well as 19.2%, 73.1%, and 7.7% in the accumulation period, respectively. Ice-melt water has a higher conversion recharge rate to groundwater and indirectly recharges river water, especially in nonmonsoon seasons. In other words, the main recharge source of river water in the lower reaches of the Mingyong Glacier basin during the ablation period is ice-melt water. In the accumulation period, the main recharge source of river water in the lower reaches of the Mingyong Glacier basin is groundwater, while nearly half of the recharge of groundwater comes from ice-melt water. Therefore, regardless of the ablation period or the accumulation period, ice-melt water is sustainable and important to this region.
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Zhang, Zhe, Yanping Li, Michael Barlage, Fei Chen, Gonzalo Miguez-Macho, Andrew Ireson, and Zhenhua Li. "Modeling groundwater responses to climate change in the Prairie Pothole Region." Hydrology and Earth System Sciences 24, no. 2 (February 17, 2020): 655–72. http://dx.doi.org/10.5194/hess-24-655-2020.
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Abstract. Shallow groundwater in the Prairie Pothole Region (PPR) is predominantly recharged by snowmelt in the spring and supplies water for evapotranspiration through the summer and fall. This two-way exchange is underrepresented in current land surface models. Furthermore, the impacts of climate change on the groundwater recharge rates are uncertain. In this paper, we use a coupled land–groundwater model to investigate the hydrological cycle of shallow groundwater in the PPR and study its response to climate change at the end of the 21st century. The results show that the model does a reasonably good job of simulating the timing of recharge. The mean water table depth (WTD) is well simulated, except for the fact that the model predicts a deep WTD in northwestern Alberta. The most significant change under future climate conditions occurs in the winter, when warmer temperatures change the rain/snow partitioning, delaying the time for snow accumulation/soil freezing while advancing early melting/thawing. Such changes lead to an earlier start to a longer recharge season but with lower recharge rates. Different signals are shown in the eastern and western PPR in the future summer, with reduced precipitation and drier soils in the east but little change in the west. The annual recharge increased by 25 % and 50 % in the eastern and western PPR, respectively. Additionally, we found that the mean and seasonal variation of the simulated WTD are sensitive to soil properties; thus, fine-scale soil information is needed to improve groundwater simulation on the regional scale.
9
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.
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Lasisi, M. O., K. F. Omotayo, and Y. M. Adeosun. "APPLICATION OF GEOGRAPHIC INFORMATION SYSTEM AND REMOTE SENSING IN GROUNWATER RECHARGE POTENTIAL OF ADO-EKITI, NIGERIA." International Journal of Agriculture, Environment and Bioresearch 07, no. 03 (2022): 215–26. http://dx.doi.org/10.35410/ijaeb.2022.5737.
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The increasing demand for freshwater has been on the increase as a result of geometric population growth, erratic climate change and urbanization has necessitated more attention and reliance on groundwater resources most especially in Ado-Ekiti, Nigeria. This necessitates the urgent need for judicious management of available groundwater resources to meet the freshwater requirements in the studied area. Geographical Information System (GIS) and Remote Sensing (RS) techniques were used to map out the groundwater recharge potential of the studied area. Google Earth and Land Satellite (LANDSAT) 7 sensor of Enhanced Thematic Mapper Plus (ETM+), path 191 and row 55 were used to acquire the satellite imageries of Ado-Ekiti. Using high resolution imageries, a Digital Elevation Model (DEM) was developed with Surfer 8 and ArcGIS 10.0 softwares to identify areas with high, medium and low groundwater recharge zones in the studied area. The elevation, slope, land use/ land cover, drainage density, lineament density, lithology, flow direction, flow length and flow accumulation maps of the study area were generated by using the DEM. The groundwater recharge potential was obtained by overlaying all the thematic maps that affected the groundwater distribution. Each thematic map was weighted according to its effect on groundwater infiltration. The results showed that areas with high lineament density, long flow length, high flow accumulation, high drainage pattern, low slope (lowland region) and vegetation have high groundwater recharge potential, and areas with medium lineament density, flow length, flow accumulation, drainage density, slope and sparse vegetation, respectively have moderate groundwater recharge potential while areas with low lineament density, short flow length, low flow accumulation, low drainage density, high slope (highland region) and sparse vegetation have low groundwater recharge potential. Better information on groundwater recharge potential of the studied area was provided via easily read and accessible maps generated from remotely sensed data and ArcGIS 10.0 software. The results also revealed that geology survey should be carried out to validate the results.
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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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Buselli, G., and D. R. Williamson. "Modeling of broadband airborne electromagnetic responses from saline environments." GEOPHYSICS 61, no. 6 (November 1996): 1624–32. http://dx.doi.org/10.1190/1.1444081.
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The removal of vegetation for the development of nonirrigated agriculture and the associated increase in groundwater recharge and discharge has caused significant areas of salinization of surface soil and water resources in Australia. At least three types of salt profiles are known to indicate the relative magnitude of recharge. These profiles may be differentiated by their resistivity structure. Since a broadband airborne electromagnetic (AEM) method offers the possibility of readily obtaining resistivity soundings, modeling was carried out to investigate the ability of a broadband AEM system to distinguish different salt profile types. Salt profile types may be represented by a four‐layer resistivity model. The use of a broadband AEM system to distinguish the relative magnitude of the resistivity of a layer of high salt accumulation and the underlying layer forms the basis for efficiently identifying areas of high or low recharge. Where the resistivity of the underlying layer is greater than that of the salt accumulation, high recharge is indicated, and a lower resistivity of this layer implies low recharge. The response of each of the salt profile models was calculated in the frequency domain and then inverted back to a layered model. With noise added to the calculated responses, the inversion results show that the depth, thickness, and resistivity of a layer of high salt accumulation can be resolved by AEM measurements. Furthermore, the resistivity of this layer can be distinguished from the resistivity of the underlying layer. A high‐recharge profile may therefore be differentiated from a low‐recharge profile with AEM measurements. Since the quadrature component of the AEM response is relatively unaffected by noise caused by the primary field, the effect of using solely the quadrature component of the response was examined briefly as a second part of the AEM modeling investigation. It is found that simultaneous inversion of the quadrature part of the spatial components measured along the line of flight and in a vertical direction gives results similar to those when both the in‐phase and quadrature parts of these components are used in the inversion.
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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.
Full textAbstract:
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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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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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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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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Ke, Tingting, Longcang Shu, and Xunhong Chen. "Modeling the groundwater recharge in karst aquifers by using a reservoir model." Water Science and Technology 68, no. 2 (July 1, 2013): 406–12. http://dx.doi.org/10.2166/wst.2013.266.
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The estimation of the groundwater recharge in a karstic system becomes an important challenge due to the great hydrodynamic variability in both time and space. This paper proposes a two reservoir conceptual model to simulate inflow into both the conduit system and the fissure network system based on the analysis of the spring hydrograph. The structure of the model and the governing equations are proposed on the basis of the physical considerations, with the assumption that flow at the outlet of the reservoirs obeys a linear threshold function. The model is applied on the Houzhai karstic underground river basin where it successfully reflects the temporal recharge distribution. The simulated accumulation recharge is 34.29 mm, which is reasonable in relation to the actual rainfall of 92.8 mm. The variations of water volume in two reservoirs represent the storage and transform characteristics of the karst aquifer system. However, this model is particularly well suited to simulate the recharge event after intensive rainfall.
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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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Ketchum, Neil J., Joseph J. Donovan, and William H. Avery. "Recharge characteristics of a phreatic aquifer as determined by storage accumulation." Hydrogeology Journal 8, no. 6 (September 7, 2000): 579–93. http://dx.doi.org/10.1007/s100400000088.
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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.
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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.
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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.
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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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Pavlovskii, Igor, Masaki Hayashi, and Daniel Itenfisu. "Midwinter melts in the Canadian prairies: energy balance and hydrological effects." Hydrology and Earth System Sciences 23, no. 4 (April 4, 2019): 1867–83. http://dx.doi.org/10.5194/hess-23-1867-2019.
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Abstract. Snowpack accumulation and depletion are important elements of the hydrological cycle in the Canadian prairies. The surface runoff generated during snowmelt is transformed into streamflow or fills numerous depressions driving the focussed recharge of groundwater in this dry setting. The snowpack in the prairies can undergo several cycles of accumulation and depletion in a winter. The timing of the melt affects the mechanisms of snowpack depletion and their hydrological implications. The effects of midwinter melts were investigated at four instrumented sites in the Canadian prairies. Unlike net radiation-driven snowmelt during spring melt, turbulent sensible heat fluxes were the dominant source of energy inputs for midwinter melt occurring in the period with low solar radiation inputs. Midwinter melt events affect several aspects of hydrological cycle with lower runoff ratios than subsequent spring melt events, due to their role in the timing of the focussed recharge. Remote sensing data have shown that midwinter melt events regularly occur under the present climate throughout the Canadian prairies, indicating applicability of the study findings throughout the region.
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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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Grinevskiy, Sergey O., Sergey P. Pozdniakov, and Ekaterina A. Dedulina. "Regional-Scale Model Analysis of Climate Changes Impact on the Water Budget of the Critical Zone and Groundwater Recharge in the European Part of Russia." Water 13, no. 4 (February 6, 2021): 428. http://dx.doi.org/10.3390/w13040428.
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Groundwater recharge by precipitation is the main source of groundwater resources, which are widely used in the European part of Russia (ER). The main goal of the presented studies is to analyze the effect of observed climate changes on the processes of groundwater recharge. For this purpose analysis of long-term meteorological data as well as water budget and groundwater recharge simulation were used. First, meteorological data of 22 weather stations, located from south (Lat 46°) to north (Lat 66°) of ER for historical (1965–1988) and modern (1989–2018) periods were compared to investigate the observed latitudinal changes in annual and seasonal averages of precipitation, wind speed, air temperature, and humidity. Second, water budget in critical zone was simulated, using codes SURFBAL and HYDRUS-1D. SURFBAL generates upper boundary conditions for unsaturated flow modelling with HYDRUS-1D, taking into account snow accumulation and melting as well as topsoil freezing, which are important processes that affect runoff generation and the infiltration of meltwater. Water budget and groundwater recharge simulations based on long-term meteorological data and soil and vegetation parameters, typical for the investigated region. The simulation results for the historical and modern periods were compared to find out the impact of climate change on the average annual and seasonal averages of surface runoff, evapotranspiration, and groundwater recharge, as well as to assess latitudinal differences in water budget changes. The results of the simulation showed, that despite a significant increase in air temperature, groundwater recharge in the southern regions did not change, but even increased up to 50–60 mm/year in the central and northern regions of ER. There are two main reasons for this. First, the observed increase in air temperature is compensated by a decrease in wind speed, so there was no significant increase in evapotranspiration in the modern period. Also, the observed increase in air temperature and precipitation in winter is the main reason for the increase in groundwater recharge, since these climate changes lead to an increase in water infiltration into the soil in the cold period, when there is no evapotranspiration.
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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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Karlović, Igor, Tamara Marković, Tatjana Vujnović, and Ozren Larva. "Development of a Hydrogeological Conceptual Model of the Varaždin Alluvial Aquifer." Hydrology 8, no. 1 (January 27, 2021): 19. http://dx.doi.org/10.3390/hydrology8010019.
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The Varaždin aquifer represents the main source of water for public supply, agricultural, and industrial purposes in the Varaždin County in NW Croatia. In the last decades, this area has experienced contamination of groundwater with nitrates. This study describes the conceptualization of the Varaždin aquifer for the purpose of developing numerical model of groundwater flow and nitrate transport. Within the study, three important elements are defined: aquifer geometry, recharge from precipitation, and other boundary conditions. 3D aquifer model revealed that Varaždin aquifer consist of three layers: upper aquifer, semipermeable interlayer, and lower aquifer. The Wetspass-M model was used for the assessment of spatial and temporal distribution of water balance components for the period 2008–2017. Results of the model indicate that the average annual precipitation is distributed as 34% groundwater recharge, 21% surface runoff, and 45% actual evapotranspiration. The maps of equipotential lines show the behavior of the aquifer system and define boundary conditions, i.e., recharge and discharge areas of the aquifer: an inflow boundary from Drava River and accumulation lake Varaždin on the northwest and north, no flow boundary on the west and south, and an outflow boundary on the east.
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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.
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Standing, J., R. Ghail, and D. Coyne. "Gas generation and accumulation by aquifer drawdown and recharge in the London Basin." Quarterly Journal of Engineering Geology and Hydrogeology 46, no. 3 (July 30, 2013): 293–302. http://dx.doi.org/10.1144/qjegh2013-030.
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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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Rybnikova, L. S., N. L. Frolova, M. G. Morozov, A. V. Komin, and P. A. Rybnikov. "Assessment of the Republic of Kalmykia artificial groundwater resources recharge at the expense of the surface runoff accumulation." IOP Conference Series: Earth and Environmental Science 979, no. 1 (February 1, 2022): 012177. http://dx.doi.org/10.1088/1755-1315/979/1/012177.
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Abstract Territory of the Republic of Kalmykia located in the northwestern part of Caspian Region relates to arid areas because of the very poorly developed hydrographic network. Annual amount of precipitation varies from 210 to 340 mm; evaporation from the water surface is 1000–1100 mm. The issue of water resources provision is critical for Kalmukia. In the conditions of Kalmykia groundwater plays an important role as it is the main and often the only source of domestic/drinking water supply. However, the groundwater use is limited due to their low natural quality. One of the ways of increasing useful groundwater resources of water intakes and particular sites of deposits, improvement of water quality and, accordingly, meeting the population’s current demand for fresh drinking water can become artificial recharge of groundwater. A source of groundwater recharge on the territory of Kalmykia can be surface runoff during the winter/spring flood or, less often, during summer/fall rain floods. The Ergeninsk Upland in the Republic of Kalmykia has been chosen for the first stage (2020-2021) of researches in terms of combination of all factors of the possibility of artificial groundwater resources accumulation.
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Megahed, Hanaa A., Abd El-Hay A. Farrag, Amira A. Mohamed, Paola D’Antonio, Antonio Scopa, and Mohamed A. E. AbdelRahman. "Groundwater Recharge Potentiality Mapping in Wadi Qena, Eastern Desert Basins of Egypt for Sustainable Agriculture Base Using Geomatics Approaches." Hydrology 10, no. 12 (December 12, 2023): 237. http://dx.doi.org/10.3390/hydrology10120237.
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In arid and hyper-arid areas, groundwater is a precious and rare resource. The need for water supply has grown over the past few decades as a result of population growth, urbanization, and agricultural endeavors. This research aims to locate groundwater recharge potential zones (GWPZs) using multi-criteria evaluation (MCE) in the Wadi Qena Basin, Eastern Desert of Egypt, which represents one of the most promising valleys on which the government depends for land reclamations and developments. These approaches have been used to integrate and delineate the locations of high groundwater recharge and the potential of the Quaternary aquifer in the Wadi Qena basin. After allocating weight factors to identify features in each case based on infiltration, land use/land cover, slope, geology, topology, soil, drainage density, lineament density, rainfall, flow accumulation, and flow direction, these thematic maps were combined. The results of the GIS modeling led to the division of the area’s groundwater recharge potential into five groups, ranging from very high (in the western part) to very low (in the eastern part of the basin). The zones with the best prospects for groundwater exploration turned out to be the alluvial and flood plains, with their thick strata of sand and gravel. The groundwater recharge potential map was validated using data from the field and earlier investigations. The promising recharging areas show high suitability for soil cultivation. The results overall reveal that RS and GIS methodologies offer insightful instruments for more precise assessment, planning, and monitoring of water resources in arid regions and anywhere with similar setups for groundwater prospecting and management.
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Gunn, John, and Chris Bradley. "Characterising Rhythmic and Episodic Pulsing Behaviour in the Castleton Karst, Derbyshire (UK), Using High Resolution in-Cave Monitoring." Water 15, no. 12 (June 20, 2023): 2301. http://dx.doi.org/10.3390/w15122301.
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The discharge from most karst springs exhibits a consistent and reasonably predictable response to recharge but a few exhibit short-term (‘rhythmic’) changes in flow that are commonly attributed to the geometry of feeder conduits and the action of siphons. This paper investigates water flow in a karst system that exhibits rhythmic and episodic changes in discharge due to variations in flow from two phreatic conduits (Main Rising (MR) and Whirlpool Rising (WR)) that pass through Speedwell Cavern en route to the springs. Water tracing experiments indicate that the conduits receive both allogenic and autogenic recharge. Flow dynamics and conduit behaviour were investigated using high-resolution (2-min) water depth data collected from MR and WR between 2012 and 2015 (when MR was dominant) and between 2021 and 2023 (when WR was dominant). Water depths were also logged in a cave at the upstream end of a conduit draining to both MR and WR and at springs. The short-term temporal variability in water depths at both MR and WR is greater than any documented in previous studies. This is attributed to conduit bedrock geometry and changes in conduit permeability due to sediment accumulation in phreatic loops, which together influence the response to recharge.
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Duppa M.T, Ir Hakim. "SURFACE FLOW REDUCTION AT APUDDLE AREA BY POROUS RECHARGE." INTERNATIONAL JOURNAL OF MANAGEMENT & INFORMATION TECHNOLOGY 11, no. 3 (August 30, 2016): 2910–15. http://dx.doi.org/10.24297/ijmit.v11i3.5119.
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Waterlogging occurs when rain is rain water that gathered  accumulation  exceeded the rainage capacity of the river and it is  causedndue to the absence of absorption infiltration into the soil this the study aimed to assess the basic characteristics of the land area of inundation, (material volcanic rocks, and chunk) and infiltration capacity this research method is the study of soil mechanics laboratory experiments using soil samples from 2 nundation areas, areas not graceful and the samples of porous material and chunks of mountain rock (sand, cement, bricks) the result showed that the characteristics of waterlogged soil including silt soils kelempungan category and has a value of permeability 0.0002099 cm/sec, permeability volcanic rocks 0.04505 cm/s, permeability blocks (sand, cement, bricks) 0.02955 cm/sec. This suggests that the volcanic rocks have large permeability values that can be just passed substantial drainage. From the analysis carried out shows the reduction of surface water to echarge the mountain rock so big that can reduce surface runoff and can also recharge ground waterreserves.
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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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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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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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French, Helen K., Mona C. Hansen, Kamilla G. Moe, and Julie Stene. "Modelling Plume Development with Annual Pulses of Contaminants Released from an Airport Runway to a Layered Aquifer, Evaluation of an In Situ Monitoring System." Water 15, no. 5 (March 4, 2023): 985. http://dx.doi.org/10.3390/w15050985.
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In cold climates, the use of de-icing chemicals in the winter can lead to groundwater contamination, especially when used in large quantities, such as at airports. Oslo Airport, Gardermoen, is situated on Norway’s largest rain-fed aquifer. Potassium formate is used to remove ice from runways and propylene glycol from airplanes; the organic parts are degradable. Most of the wells to monitor the spread of de-icing chemicals in the underlying aquifer have well screens near the groundwater level, while the runways and the source of de-icing chemicals are near the groundwater divides, where vertical flow is expected. The objective of this study is to demonstrate the importance of layers and time-varying recharge on the spreading of contaminant plumes in an aquifer near a groundwater divide. This is done with numerical modelling. The model results show increased vertical transport of the added tracer in the presence of horizontal layers, both continuous and discontinuous, in the aquifer. With certain distributions of hydraulic conductivity, Ks, we demonstrate that deeper monitoring wells are required. With the scenarios modelled here, time-varying recharge has a weaker effect on plume distribution. Measured concentrations of potassium and total organic carbon show the cyclic effect of seasonally varying recharge of contaminants, and an asymptotic accumulation of concentration over time, that is consistent with the model runs. In conclusion, groundwater monitoring systems near a groundwater divide should include multi-level samplers to ensure control of the vertical plume movement.
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Barker, Simon J., Colin J. N. Wilson, Daniel J. Morgan, and Julie V. Rowland. "Rapid priming, accumulation, and recharge of magma driving recent eruptions at a hyperactive caldera volcano." Geology 44, no. 4 (March 9, 2016): 323–26. http://dx.doi.org/10.1130/g37382.1.
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Mladenov, Natalie, Philippa Huntsman-Mapila, Piotr Wolski, Wellington R. L. Masamba, and Diane M. McKnight. "Dissolved organic matter accumulation, reactivity, and redox state in ground water of a recharge wetland." Wetlands 28, no. 3 (September 2008): 747–59. http://dx.doi.org/10.1672/07-140.1.
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Chen, Jing, Mingming Luo, Li Wan, Jing Wang, Yiqun Gan, and Hong Zhou. "Accumulation, conversion and storage of solute from sinkholes to karst spring under concentrated recharge conditions." Journal of Hydrology 620 (May 2023): 129396. http://dx.doi.org/10.1016/j.jhydrol.2023.129396.
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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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Nightingale, Harry I. "ACCUMULATION OF AS, NI, CU, AND PB IN RETENTION AND RECHARGE BASINS SOILS FROM URBAN RUNOFF." Journal of the American Water Resources Association 23, no. 4 (August 1987): 663–72. http://dx.doi.org/10.1111/j.1752-1688.1987.tb00840.x.
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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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El Mrabet, Elyasse, Lhoussaine El Mezouary, and Bouabid El Mansouri. "A study of water infiltration basin and clogging using column experiments." E3S Web of Conferences 314 (2021): 04005. http://dx.doi.org/10.1051/e3sconf/202131404005.
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The clogging of infiltration basins is the main problem affecting the proper functioning of groundwater artificial recharge systems. In this study, several parameters have been varied to understand their impacts on water infiltration. The experimental results show that the effect of initial humidity is significant for less porous material such as silty soil (Hamri) and sand. The air bubbles are also an important factor to take into consideration since when trapped within porous structures, it forms a barrier for the displacement of water infiltration. The accumulation of suspended particles in stormwater can contribute to clogging by creating a light layer due to the finest particles, which remain in suspension for a long time. Finally, for the tested materials and experimental conditions, we observed that a combination of a silty soil and sand layer in the design of infiltration basins was more practical than a combination of sand and gravel. The latter, despite its high porosity, could release very fine particles; which would create a cement layer of clogging when deposited at the interface. This layer is an obstacle for water infiltration, thus rendering the device thus constructed unsuitably for groundwater recharge, by reducing its life.
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Guggenmos, M. R., C. J. Daughney, B. M. Jackson, and U. Morgenstern. "Regional-scale identification of groundwater-surface water interaction using hydrochemistry and multivariate statistical methods, Wairarapa Valley, New Zealand." Hydrology and Earth System Sciences 15, no. 11 (November 15, 2011): 3383–98. http://dx.doi.org/10.5194/hess-15-3383-2011.
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Abstract. Identifying areas of interaction between groundwater and surface water is crucial for effective environmental management, because this interaction is known to influence water quantity and quality. This paper applies hydrochemistry and multivariate statistics to identify locations and mechanisms of groundwater-surface water interaction in the pastorally dominated Wairarapa Valley, New Zealand. Hierarchical Cluster Analysis (HCA) and Principal Components Analysis (PCA) were conducted using site-specific median values of Ca, Mg, Na, K, HCO3, Cl, SO4 and electrical conductivity from 22 surface water sites and 246 groundwater sites. Surface water and groundwater monitoring sites were grouped together in three of the seven clusters identified by HCA, with the inference made that similarities in hydrochemistry indicate groundwater-surface water interaction. PCA indicated that the clusters were largely differentiated by total dissolved solids concentration, redox condition and ratio of major ions. Shallow aerobic groundwaters, located in close proximity to losing reaches of rivers, were grouped with similar Ca-HCO3 type surface waters, indicating potential recharge to aquifers from these river systems. Groundwaters that displayed a rainfall-recharged chemical signature with higher Na relative to Ca, higher Cl relative to HCO3 and an accumulation of NO3 were grouped with neighbouring surface waters, suggesting the provision of groundwater base flow to these river systems and the transfer of this chemical signature from underlying aquifers. The hydrochemical techniques used in this study did not reveal groundwater-surface water interaction in some parts of the study area, specifically where deep anoxic groundwaters, high in total dissolved solids with a distinct Na-Cl signature, showed no apparent link to surface water. The drivers of hydrochemistry inferred from HCA and PCA are consistent with previous measurements of 18O, water age and excess air. Overall, this study has shown that multivariate statistics can be used as a rapid method to identify groundwater-surface water interaction at a regional scale using existing hydrochemical datasets.