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The purpose of this study was to discuss the change in groundwater level and quantity supplemented to Mihuaishun area from South to North Water Division Project. In this study, the method of numerical simulation was adopted to predict and analysis of the trend of groundwater level in the study area within 20 years. The survey concluded that the cumulative loss of groundwater resources in Mihuaishun area in 2007 ~ 2016 reaches -1.784 × 109 m³. According to the forecast, after the water source of South-to-North Water Division continues to recharge the aquifers at the rate of 0.12 billion m³/a for ten years, the local groundwater equilibrium changes from negative to positive, and the water level in the central funnel area increases by 25m. In addition, the artificial recharge of multiple water sources is also related to local hydrology geological conditions. The impacts of the obtained results are analyzing comprehensively the influence of South to North Water Division supplement on groundwater and providing reference for underground regulation and unified regulation of water resources after the water source of South-to-North Water Division transferred into Beijing. [ABSTRACT FROM AUTHOR]

The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies. [ABSTRACT FROM AUTHOR]

Spatially constant porosity and hydraulic conductivity are usually applied in hydrological studies related to land reclamations. However, the grain sorting and the degree of compaction within land reclamations differ per placement method. A study area at Maasvlakte II, the Netherlands, and the four other land reclamations that could be found in the literature are considered that were constructed by a combination of bottom dumping, rainbowing and discharging the sand-water mixture by pipeline. The structures of the porous media are derived for each placement method and validated by comparison with semi-variograms of cone-penetration tests. It is found that all placement methods lead to some degree of heterogeneity, so that the hydraulic conductivity in these land reclamations is not constant. This is due to the degree of segregation of the grain sizes that differs between placement methods. Segregation even varies within a specific placement method because of its characteristics and site-specific circumstances such as settling depth, grain-size distribution and angularity resulting from grain type. If land reclamations are considered for aquifer storage and recovery for freshwater supply, it should be considered that the recovery efficiency will be affected by both the properties of the material in the borrow area and by the placement methods including their spatial configuration as applied during construction of the reclamation. [ABSTRACT FROM AUTHOR]

Highlights • Building settlements are observed to increase progressively during redevelopment. • Combined recharge is proposed to prevent redevelopment-induced settlement. • Field tests are conducted to study the effect of combined recharge. • Combined recharge can ensure no absolute surface settlement during redevelopment. • We propose optimized plan to help better use recharge for settlement control. Abstract Artificial recharge is an effective way to minimize dewatering-induced ground settlements in deep excavation. To ensure the success of a long-term recharge, it is necessary to redevelop recharge wells (i.e., pumping) periodically to prevent well clogging. Field measurements show that ground settlements will occur during the well redevelopment. This paper proposed a method referred to as the combined recharge to eliminate settlement during well redevelopment. In the proposed method, a row of recharge wells (AR well) is added at the side of the traditional recharge wells (PR wells) to compensate water loss due to PR well redevelopment. Two field tests (with and without use of combined recharge) are conducted to investigate the ground response to recharge and redevelopment. Test results show that building settlements will increase progressively during redevelopment for case without combined recharge. However, there are no significant surface settlements during redevelopment for the case with combined recharge. [ABSTRACT FROM AUTHOR]

Freshwater groundwater resources at north Kuwait were contaminated by infiltrated oil as well as sea water that was used to fight the oil-well fires during the liberation of Kuwait in 1991. This paper investigates the feasibility of five remediation options to restore the polluted aquifers. These options include: (i) pump and treat of contaminated groundwater; (ii) cleaning the aquifer formation; (iii) construction of additional desalination plant; (iv) constructing additional storage tanks, and (v) development of artificial aquifer recharge schemes. The basis for this assessment study is to supply minimum basic drinking water to Kuwait City at a total rate of 50,000 m3/day in an emergency for up to one year based on essential basic need of 32 liters per capita per day. To compare these options, a decision matrix to select suitable remediation options using Multiple Criteria Decision Analysis (MCDA) approach is developed. The cost was given a relative weight of 20 whereas other criteria are given weight of 10. Based on these MCDA scores, it was found that option 3, namely, establishing an additional water desalination plant, is the most feasible option followed by option 5, artificial recharge of aquifers. [ABSTRACT FROM AUTHOR]

A transient numerical groundwater flow model using MODFLOW-NWT was set up and calibrated for Hanoi city, Vietnam, to understand the local groundwater flow system and to suggest solutions for sustainable water resource management. Urban development in Hanoi has caused a severe decline of groundwater levels. The present study evaluates the actual situation and investigates the suitability of managed aquifer recharge (MAR) to stop further depletion of groundwater resources. The results suggest that groundwater is being overexploited, as vast cones of depression exist in parts of the study area. Suitable locations to implement two MAR techniques—riverbank filtration and injection wells—were identified using multi-criteria decision analysis based on geographic information system (GIS). Three predictive scenarios were simulated. The relocation of pumping wells towards the Red River to induce riverbank filtration (first scenario) demonstrates that groundwater levels can be increased, especially in the depression cones. Groundwater levels can also be improved locally by the infiltration of surplus water into the upper aquifer (Holocene) via injection wells during the rainy season (second scenario), but this is not effective to raise the water table in the depression cones. Compared to the first scenario, the combination of riverbank filtration and injection wells (third scenario) shows a slightly raised overall water table. Groundwater flow modeling suggests that local overexploitation can be stopped by a smart relocation of wells from the main depression cones and the expansion of riverbank filtration. This could also avoid further land subsidence while the city’s water demand is met. [ABSTRACT FROM AUTHOR]

To investigate the effect of recharge water temperature on bioclogging processes and mechanisms during seasonal managed aquifer recharge (MAR), two groups of laboratory percolation experiments were conducted: a winter test and a summer test. The temperatures were controlled at ~5±2 and ~15±3 °C, and the tests involved bacterial inoculums acquired from well water during March 2014 and August 2015, for the winter and summer tests, respectively. The results indicated that the sand columns clogged ~10 times faster in the summer test due to a 10-fold larger bacterial growth rate. The maximum concentrations of total extracellular polymeric substances (EPS) in the winter test were approximately twice those in the summer test, primarily caused by a ~200 μg/g sand increase of both loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). In the first half of the experimental period, the accumulation of bacteria cells and EPS production induced rapid bioclogging in both the winter and summer tests. Afterward, increasing bacterial growth dominated the bioclogging in the summer test, while the accumulation of LB-EPS led to further bioclogging in the winter test. The biological analysis determined that the dominant bacteria in experiments for both seasons were different and the bacterial community diversity was ~50% higher in the winter test than that for summer. The seasonal inoculums could lead to differences in the bacterial community structure and diversity, while recharge water temperature was considered to be a major factor influencing the bacterial growth rate and metabolism behavior during the seasonal bioclogging process. [ABSTRACT FROM AUTHOR]

In the Indian water policy, Managed Aquifer Recharge (MAR) is considered as one of the best supply side water management options to face groundwater depletion. It is expected to optimize the resource as well as attain environmental sustainability and meet water demands and social justice. It is also expected to be implemented with a paradigmatic shift in water management. From policy to practices, at the local level, numerous recharge structures exist, are built or planned and reveal controversial implementation. With a sociohistorical approach, our paper analyses the trajectory of MAR implementation in the Pondicherry Region (South India). Through interviews and observations, the trajectories of two local projects are scrutinized, The Tank Rehabilitation Programs in Pondicherry district and a recharge shaft in Kiliyanur. Stakeholders' strategies and values regarding MAR are analysed and how local appropriation leads to adaptation and diversion. Finally, there is no paradigmatic shift going with MAR implementation. Instead, MAR is shown as a consensual policy because it is a possible compromise between groundwater conservation, optimization of the resource, satisfaction of the users and social justice, but controversial positions and oppositions should be acknowledged within implementation. The paper discusses opposed conceptions of MAR: participatory vs. expert driven, demand vs. supply driven and traditional vs. modern. [ABSTRACT FROM AUTHOR]

Artificial groundwater revive assumes an essential part in feasible administration of groundwater assets. The present investigation was done to distinguish the simulated groundwater revive zones in Gandheswari watershed utilizing remote detecting and geological data framework (GIS) for increasing groundwater assets. The investigation zone has been confronting extreme water shortage because of concentrated farming for as far back as couple of years. Morphometric parameters are dissected to comprehend the watershed qualities and its effect on the water assets for example bifurcation proportion shows high surface spillover and low revive. Low seepage thickness indicates porous strata, thick vegetation, and low alleviation. Though, incline, geography and geomorphological mapping is done to separate groundwater potential zones for future investigation in the examination region. Slant is contrarily relative to penetration. In light of AHP, different ground water potential zones are discovered like amazing, great, great, poor, and extremely poor zones. Toward the end, last outline of manufactured revive sited determination depends on the dirt sort, slant, seepage arrange, and so on. The coordinated examination helps in outlining reasonable destinations for building water gathering structures. Check dams, permeation tanks, and Nala bund are proposed at first, second or third waste requests at Micro Basins with pediment. Nala bund and check dam are proposed at MB-2 and MB-4 though, at MB-3 check dams and permeation tanks are proposed in order to ration the regular assets display in the watershed. At last, the best achievable water reaping structures have been proposed inside the watershed region utilizing remote detecting and GIS strategies. [ABSTRACT FROM AUTHOR]

An optimization approach is used for the operation of groundwater artificial recharge systems in an alluvial fan in Beijing, China. The optimization model incorporates a transient groundwater flow model, which allows for simulation of the groundwater response to artificial recharge. The facilities’ operation with regard to recharge rates is formulated as a nonlinear programming problem to maximize the volume of surface water recharged into the aquifers under specific constraints. This optimization problem is solved by the parallel genetic algorithm (PGA) based on OpenMP, which could substantially reduce the computation time. To solve the PGA with constraints, the multiplicative penalty method is applied. In addition, the facilities’ locations are implicitly determined on the basis of the results of the recharge-rate optimizations. Two scenarios are optimized and the optimal results indicate that the amount of water recharged into the aquifers will increase without exceeding the upper limits of the groundwater levels. Optimal operation of this artificial recharge system can also contribute to the more effective recovery of the groundwater storage capacity. [ABSTRACT FROM AUTHOR]

Clogging, the major obstacle in aquifer storage and recovery (ASR) applications, causes declines in recharge rates and ultimately the failure of artificial recharge systems. Clogging is generally triggered by physical processes, which involve the accumulation of suspended solids from recharge water, the release of fine particles from soils and aquifers and their migration, and the formation of gas barriers from the entrapped air in recharge water and biogenic gases. Physical clogging is then followed by biological processes (e.g., the growth of microorganisms and the accumulation of biomass). It can be further aggravated by chemical reactions leading to mineral precipitation. Prior to artificial recharge, source water can be pretreated via sedimentation, coagulation, filtration, advanced oxidation, and disinfection to lessen the clogging potential. Although such preventive measures are useful, clogging will eventually occur in recharge systems, thus necessitating the rehabilitation. The rehabilitation methods include backwashing, scrubbing, surging, jetting, under-reaming, acidification, and biociding. Notably, the methods applied vary with the type of recharge systems: surface infiltration systems, vadose zone infiltration systems, and aquifer injection wells. Among them, surface infiltration systems are most cost-effective and easiest to install and maintain. Even if field conditions are not adequate for their implementation, surface infiltration systems can be used in conjunction with the other recharge systems. [ABSTRACT FROM AUTHOR]

To assess recharge through floodwater spreading, three wells, approx. 30 m deep, were dug in a 35-year-old basin in southern Iran. Hydraulic parameters of the layers were measured. One well was equipped with pre-calibrated time domain reflectometry (TDR) sensors. The soil moisture was measured continuously before and after events. Rainfall, ponding depth and the duration of the flooding events were also measured. Recharge was assessed by the soil water balance method, and by calibrated (inverse solution) HYDRUS-1D. The results show that the 15 wetting front was interrupted at a layer with fine soil accumulation over a coarse layer at the depth of approx. 4 m. This seemed to occur due to fingering flow. Estimation of recharge by the soil water balance and modelling approaches showed a downward water flux of 55 and 57% of impounded floodwater, respectively. [ABSTRACT FROM AUTHOR]

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Abstract: Groundwater is an important component of the water supply, and overexploitation has triggered many problems in the Beijing Plain. The South‐to‐North Water Transfer Project has been proposed as a promising solution to alleviate these problems. Evaluation of different scenarios of groundwater management after the implementation of the South‐to‐North Water Transfer Project is necessarily required. In this study, a numerical model of groundwater flow was established using FEFLOW software and was well calibrated by parameter optimization and groundwater withdrawal inversion in the Beijing Plain. Sixteen scenarios that considered groundwater exploitation, artificial recharge, and precipitation were designed to simulate the groundwater dynamics after 11 years of the project. The results showed that the groundwater level in the study area would recover to various degrees due to the reductions of groundwater withdrawal and the increments of infiltration; additionally, it was concluded that groundwater was significantly affected by precipitation. Generally, in the designed scenarios, the groundwater‐level increment in the upper streams of the model area was higher than that in the lower streams. The groundwater level would obviously increase from artificial recharge in the immediate and adjacent areas. In addition, modes of reducing exploitation had no significant influence on the change in groundwater level during the 11‐year study period. The developed model offers a reliable and effective way to improve groundwater management. [ABSTRACT FROM AUTHOR]

Yang, Y.; Wu, J.; Lin, J.; Wang, J.; Zhou, Z., and Wu, J., 2018. An efficient simulation–optimization approach for controlling seawater intrusion. In: Wang, D. and Guido-Aldana, P.A. (eds.), Select Proceedings from the 3rd International Conference on Water Resource and Environment (WRE2017). Journal of Coastal Research, Special Issue No. 84, pp. 10–18. Coconut Creek (Florida), ISSN 0749-0208. The management of freshwater stored in coastal aquifers involves decisions regarding not only the sustainable utilization and exploration of optimal coastal groundwater resources but also the designing of optimal strategies for controlling seawater intrusion (SI). Simultaneously optimizing pumping operation, the extent of SI, and design of mitigation measures is a challenging task because mitigating SI has become imperative for groundwater management of coastal aquifers. This study proposed a simulation-optimization framework (SWT-NPTSGA) to search Pareto-optimal solutions for estimating the optimal pumping and artificial recharge schemes under complicated SI constraints. The SWT-NPTSGA is based on a combination of a new hybrid multi-objective evolutionary algorithm, the niched Pareto tabu search combined with a genetic algorithm, and the numerical variable-density groundwater flow and transport model. Three different management scenarios, pumping only, injection only, and combined pumping and injection (P&I), were designed in a synthetic application to evaluate the efficiency of the proposed methodology. The results showed that the P&I scenario could generate comprehensive information for multi-objective decision-making. The SI mitigation measures by artificial recharge could offer the most groundwater supply and the least area of seawater intrusion. The optimization results showed the potential feasibility of the proposed methodology for managing groundwater resources and controlling SI in coastal aquifers. [ABSTRACT FROM AUTHOR]

Managed aquifer recharge (MAR) is a well-known technique for improving water quality and increasing groundwater resources. Denitrification (i.e. removal of nitrate) can be enhanced during MAR by coupling an artificial recharge pond with a permeable reactive layer (PRL). In this study, we examined the suitability of a multi-isotope approach for assessing the long-term effectiveness of enhancing denitrification in a PRL containing vegetal compost. Batch laboratory experiments confirmed that the PRL was still able to enhance denitrification two years after its installation in the infiltration pond. At the field scale, changes in redox indicators along a flow path and below the MAR-PRL system were monitored over 21 months during recharge and non-recharge periods. Results showed that the PRL was still releasing non-purgeable dissolved organic carbon five years after its installation. Nitrate concentration coupled with isotopic data collected from the piezometer network at the MAR system indicated that denitrification was occurring in the saturated zone immediately beneath the infiltration pond, where recharged water and native groundwater mix. Furthermore, longer operational periods of the MAR-PRL system increased denitrification extent. Multi-isotope analyses are therefore proved to be useful tools in identifying and quantifying denitrification in MAR-PRL systems. [ABSTRACT FROM AUTHOR]

With the rapid development and use of ground-source heat-pump (GSHP) systems in China, it has become imperative to research the effects of associated long-term pumping and recharge processes on ground deformation. During groundwater GSHP operation, small particles can be transported and deposited, or they can become detached in the grain skeleton and undergo recombination, possibly causing a change in the ground structure and characteristics. This paper presents a mathematical ground-deformation model that considers particle transportation and deposition in porous media based on the geological characteristics of a dual-structure stratum in Wuhan, eastern China. Thermal effects were taken into consideration because the GSHP technology used involves a device that uses heat from a shallow layer of the ground. The results reveal that particle deposition during the long-term pumping and recharge process has had an impact on ground deformation that has significantly increased over time. In addition, there is a strong correlation between the deformation change (%) and the amount of particle deposition. The position of the maximum deformation change is also the location where most of the particles are deposited, with the deformation change being as high as 43.3%. The analyses also show that flow of groundwater can have an effect on the ground deformation process, but the effect is very weak. [ABSTRACT FROM AUTHOR]

The groundwater flow system is typical dissipative structure system, and its evolution can be described with system information entropies. The information entropies of groundwater in Shijiazhuang City had been calculated between 1960 and 2005, and the results show that the entropies have a decreasing trend throughout the research period, and they can be divided into our stages based on the groundwater flow system entropy variation as follows: entropy steady period (1960–1965), entropy decreasing period (1965–1980), entropy increasing period (1980–1995) and secondary entropy decreasing period (1995–2005); understanding the major and significant driving the pattern changing forces of groundwater levels is essential to groundwater management,. A new method of grey correlation analysis has been presented, and the results show that, the grey correlation grade between groundwater flow system information entropies and precipitation series is γ01 = 0.749, the grey correlation grade between groundwater flow system information entropies and groundwater withdrawal series is γ02 = 0.814, as the groundwater withdrawal is the main driving force of groundwater flow system entropy variation; based on the numerical simulation results, information entropy increased with artificial recharge, and a smaller recharge water volume would enhance the information entropy drastically, but then doubled water would not increase the information correspondingly, which could be useful to assess the health state of groundwater flow systems.

http://dx.doi.org/10.17014/ijog.vol4no3.20093Significant groundwater level drawdown caused by groundwater abstractions has been reported to occur in Bandung and its surrounding area. One potential method to recover the groundwater condi- tion is artifical recharge, considering high quantity of rainfall in this area. In this research, numerical simulation has been performed in order to predict groundwater condition in the next five years, if: 1) no recovery action is taken (do-nothing) (Scenario 1), and 2) artificial recharge is performed (Scenario 2). Hydrogeological condition reconstruction required for physical model development reveals that the main aquifer in the researched area is Cibeureum Formation, which comprises volcanic fans; the main aquitard is Kosambi Formation, crasisting of lake deposit, whilst the hydrogeologic basement in the research area is the Cikapundung Formation, other Quaternary volcanic rocks, except the Cibeureum Formation, and Tertiary rock units. The recharge area is the areas where the Cibeureum Formation crops out. The result of numerical simulation of Scenario 1 shows that if there is no recovery action taken on the groundwater condition, then in year 2013 the Critical Zone will increase about 116 % and the Damage Zone will increase about 570 %. The result of this scenario also shows that there will be groundwater mining in several areas in the Damage Zone with the total area of 244 km2 or 41 % of the total confined aquifer area. Result of the numerical simulation of Scenario 2 shows that the artificial recharge in the above Critical and Damage Zones will effectively recover groundwater condition in year 2013 which means is, the whole area becomes Safe Zone. The amount of the artificial recharge is about 164 million m3/year and it started from year 2009. The artificial recharge means recharge well, surface reservoir, or recharge ditch where the Cibeureum Formation crops out, or injection well where this formation does not crop out.

A three-dimensional groundwater model was used to improve water resource management for a study area in north-west Switzerland, where drinking-water production is close to former landfills and industrial areas. To avoid drinking-water contamination, artificial groundwater recharge with surface water is used to create a hydraulic barrier between the contaminated sites and drinking-water extraction wells. The model was used for simulating existing and proposed water management strategies as a tool to ensure the utmost security for drinking water. A systematic evaluation of the flow direction between existing observation points using a developed three-point estimation method for a large number of scenarios was carried out. It is demonstrated that systematically applying the developed methodology helps to identify vulnerable locations which are sensitive to changing boundary conditions such as those arising from changes to artificial groundwater recharge rates. At these locations, additional investigations and protection are required. The presented integrated approach, using the groundwater flow direction between observation points, can be easily transferred to a variety of hydrological settings to systematically evaluate groundwater modelling scenarios. [ABSTRACT FROM AUTHOR]

The rapid growth of population and agricultural and industrial activities has caused an increase in demand on the Jeffara aquifers of Gabes (southeast Tunisia). In fact, the over-pumping of this aquifer system has resulted in water-level declines ranging from 0.25 to 1 m/year during the past three decades. The aim of this study is to identify favourable artificial recharge sites of this aquifer system based on the combined use of remotely sensed data, a geographic information system (GIS), the Shuttle Radar Topography Mission (SRTM) product and a multiple criteria decision making (MCDM) technique. The delineation of artificial recharge zones shows high to moderate potential for groundwater recharge (40%) in the Gabes region, with high precision of good potential proposed sites. Recharge processes need to account for natural conditions and ecosystems. [ABSTRACT FROM AUTHOR]

Engineers who are involved in urban infrastructure projects, havefrequently faced the problems of cost estimation, economic, financial analysis, rate analysis, project benefit and cost analysis etc. An idea of using groundwater recharge wells in conjunction with the storm water drainage system has been proposed in this study. This paper shows the comparative analysis of cost estimation of the storm water drainage system with and without recharge well for the benefits of a new urban areain Surat city (India). Two types of storm water drainage systemhave been utilized; (1) conventional storm water drainage system (without ground water recharge wells), (2) storm water drainage system with ground water recharge wells. The ultimate findings of this paper are summarised as follows; (1) tangible benefits of 25.43% compared to a conventional drainage system. (2) in terms of intangible benefits, it helps to improve ground water quality and quantity with raised ground water table. Lastly, the economic analysis is carried out for both types of storm water drainage system with the findings of the optimum diameter of ground water recharge well. [ABSTRACT FROM AUTHOR]

A reactive barrier that consisted of vegetable compost, iron oxide and clay was installed in an infiltration basin to enhance the removal of emerging organic compounds (EOCs) in the recharge water. First-order degradation rates and retardation factors were jointly estimated for 10 compounds using a multilayer reactive transport model, whose flow and conservative transport parameters were previously estimated using hydraulic head values and conservative tracer tests. Reactive transport parameters were automatically calibrated against the concentration of EOCs measured at nine monitoring points. The degradation rate of each compound was estimated for three zones defined according to the redox state, and retardation coefficients were estimated in two zones defined according to the organic matter content. The fastest degradation rates were obtained for the reactive barrier, and the estimated values were similar to or higher than those estimated in column and/or field experiments for most of the compounds (8/10). Estimated retardation coefficients in the reactive barrier were higher than in the rest of the aquifer in most cases (8/10) and higher than those values estimated in previous studies. Based on the results obtained in this study the reactive barrier seems to be able to enhance the removal of EOCs. [ABSTRACT FROM AUTHOR]

The spatial and temporal variation of moisture distribution, overall water balance and quantity of infiltrated water in the vadose zone of the Sidi Bouzid Plain (Tunisia) during successive flooding events is quantified in this study. The variation in water content in response to environmental factors such as evaporation and water root uptake is also highlighted. One-dimensional flow simulations in the deep vadose zone were conducted at three spreading perimeters located near Wadi El Fekka. The hydraulic boundary conditions of a time-dependent water blade applied to the soil surface were determined from measured flood hydrographs. For the chosen wet year, the successive flooding events contributed to a significant artificial recharge of the natural groundwater. Although the soil hydraulic parameters did not vary strongly in space, flow simulations showed significant differences in the overall water balance of approximately 9–16% for the various spreading perimeters. [ABSTRACT FROM PUBLISHER]

Sustainable groundwater production from karst aquifers is primarily dictated by its recharge rate. Therefore, it is essential to accurately quantify annual groundwater recharge in order to limit overexploitation and to evaluate artificial methods for groundwater enrichment. Infiltration during erratic flood events in karst basins may substantially contribute to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, impede accurate quantification of the actual contribution of flood waters to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge accrued during runoff events in a karst aquifer. The role of karst conduits on flash flood infiltration was examined during four flood and controlled runoff events in the Soreq creek near Jerusalem, Israel. We distinguished between direct infiltration, percolation through karst conduits, and diffuse infiltration—the latter of which is most affected by evapotranspiration. A water balance was calculated for the 2014/15 hydrological year using the Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS). Simulations show that 6.8 to 19.2% of the annual recharge volume was added to the aquifer from infiltration of runoff losses along the creek through the karst system. [ABSTRACT FROM AUTHOR]

To improve the efficiency of utilizing water resources in arid areas, the mechanism of artificial recharge effecting on groundwater reservoir was analyzed in this research. Based on a generalized groundwater reservoir in a two-dimensional sand tank model, different scenarios of the infiltration basin location and recharge intensity are designed to study how to improve the efficiency of groundwater reservoir artificial recharge. The effective storage capacity and the effective storage rate are taken as the main parameters to analyze the relation between recharge water volume and storage capacity. By combining with groundwater flow system theory, FEFLOW (Finite Element subsurface FLOW system) is adopted to set up the groundwater numerical model. It is used to verify the experiment results and to make deep analysis on the rule of water table fluctuations and groundwater movement in the aquifer. Based on the model, different scenarios are designed to examine the combined effect of recharge intensity and intermittent periods. The research results show that: the distance between infiltration basin and pumping well should be shortened appropriately, but not too close; increasing recharge intensity helps to enlarge the effective storage capacity, but it can also reduce the effective storage rate, which goes against the purpose of effective utilization of water resources; and, the recharge intensity and recharge duration should be given full consideration by the actual requirements when we take the approach of intermittent recharge to make a reasonable choice. [ABSTRACT FROM AUTHOR]

Observations are reported on (i) groundwater recharge rates under various types of vegetation as measured with megalysimeters in the dunes, (ii) freshwater lenses along the Dutch North Sea coast in the early 1900s, and (iii) rainwater lenses that develop on top of laterally migrating, artificially recharged riverwater. Subsequently analytical methods are presented to estimate annual natural groundwater recharge as function of rainfall and vegetation, and to calculate the size, shape and transition zone of freshwater lenses on saline groundwater and rainwater lenses on infiltrated riverwater. An empirical correction factor, based on the hydraulic resistance of an aquitard within the freshwater lens, is proposed to account for the frequently observed reduction of the Ghyben-Herzberg ratio of 40. This factor raises the groundwater table, reduces the depth of the fresh/salt interface and increases the lens formation time. The suite of methods offers a tool box for knowledge based water management of dune systems, by rapidly predicting: (i) more or less autonomous changes due to sealevel rise, climate change and vegetation development; and (ii) the potential (side) effects of interventions. Knowing what happened or will happen to the fresh water lens or a rainwater lens is important, because changes impact on important natural habitat parameters such as salinity, depth to groundwater table, decalcification rate (and thus on pH, Ca/Al, PO, NH) and nutrient availability, and on drinking water supply. The analytical models are applied to predict effects of sealevel rise, coastal progradation, vegetation changes, and increased temperature of coastal air and river water to be infiltrated. [ABSTRACT FROM AUTHOR]

Recent urban development and population growth in Shahrood tend to adopt a strategy for ground water management. This project, which is a descriptive- analytic type study based on field observation and laboratory analysis, aims to delineate proper sites for groundwater artificial recharge using integrated AHP-TOPSIS. First, the study area was delineated using remote sensing techniques. Then, appropriate criteria including 5 main criteria and 12 sub-criteria were obtained by field observation and literature review. Then, the appropriate sites for groundwater recharge were determined. The process of the used method consists of designing hierarchical structure of the project, preparation of pairwise comparison matrices, weighting criteria and sub criteria values by experts, and ultimately ranking them by TOPSIS method. Results showed that lithology, slope, water table depth, and land use have the main role in sites delineation. A number of control sites were employed for model validation that indicates 87.20 percent accuracy. Overally, 73.6 and 82.12 percent of the total area were grouped as very suitable and suitable classes, respectively [ABSTRACT FROM AUTHOR]