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1.
Sources of groundwater recharge to the Badain Jaran Desert in China have been investigated using geochemical and isotopic techniques. Stable isotope compositions (δ 18O and δ 2H) of shallow groundwater and surface water from oasis lakes evolve from a starting composition considerably depleted compared to local unsaturated zone moisture, confirming inferences from chloride mass balance that direct infiltration of precipitation is not a volumetrically important source of recharge to the shallow aquifer in the study area. Shallow phreatic and deeper confined groundwater bodies appear unconnected based on chemical composition and radiocarbon activities. Hydrogeologic evidence points toward a bordering mountain range (Yabulai) as a likely recharge zone, which is consistent with tracer results. A mean residence time in the range of 1–2 ka for the desert’s southeastern margin is inferred from radiocarbon. These results reveal that some replenishment to the desert aquifer is occurring but at a rate much lower than previously suggested, which is relevant for water resources planning in this ecologically sensitive area. 相似文献
2.
Recently, Ras Sudr (the delta of Wadi Sudr) area received a great amount of attention due to different development expansion
activities directed towards this area. Although Quaternary aquifer is the most prospective aquifer in Ras Sudr area, it has
not yet completely evaluated. The present work deals with the simulation of the Quaternary groundwater system using a three-dimensional
groundwater flow model. MODFLOW code was applied for designing the model of the Ras Sudr area. This is to recognize the groundwater
potential as well as exploitation plan of the most prospective aquifer in the area. The objectives were to determine the hydraulic
parameters of the Quaternary aquifer, to estimate the recharge amount to the aquifer, and to determine the hydrochemistry
of groundwater in the aquifer. During this work, available data has been collected and some field investigation has been carried
out. Groundwater flow model has been simulated using pilot points’ method. SEAWAT has been also applied to simulate the variable-density
flow and sea water intrusion from the west. It can be concluded that: (1) the direction of groundwater flow is from the east
to the west, (2) the aquifer system attains a small range of log-transformed hydraulic conductivity. It ranges between 3.05
and 3.35 m/day, (3) groundwater would be exploited by about 6.4 × 10 6 m 3/year, (4) the estimated recharge accounts for 3 × 10 6 m 3/year, (5) an estimated subsurface flow from the east accounts for 2.7 × 10 6 m 3/year, (6) the increase of total dissolved solids (TDS) most likely due to dilution of salts along the movement way of groundwater
from recharge area to discharge area in addition to a contribution of sea water intrusion from the west. Moreover, it is worth
to note that a part of TDS increase might be through up coning from underlying more saline Miocene sediments. It is recommended
that: (1) any plan for increasing groundwater abstraction is unaffordable, (2) reliable estimates of groundwater abstraction
should be done and (3) automatic well control system should be made. 相似文献
3.
The Krishni–Yamuna interstream area is a micro-watershed in the Central Ganga Plain and a highly fertile track of Western
Uttar Pradesh. The Sugarcane and wheat are the major crops of the area. Aquifers of Quaternary age form the major source of
Irrigation and municipal water supplies. A detailed hydrogeological investigation was carried out in the study area with an
objective to assess aquifer framework, groundwater quality and its resource potential. The hydrogeological cross section reveals
occurrence of alternate layers of clay and sand. Aquifer broadly behaves as a single bodied aquifer down to the depth of 100 m bgl
(metre below ground level) as the clay layers laterally pinch out. The depth to water in the area varies between 5 and 16.5 m bgl.
The general groundwater flow direction is from NE to SW with few local variations. An attempt has been made to evaluate groundwater
resources of the area. The water budget method focuses on the various components contributing to groundwater flow and groundwater
storage changes. Changes in ground water storage can be attributed to rainfall recharge, irrigation return flow and ground
water inflow to the basin minus baseflow (ground water discharge to streams or springs), evapotranspiration from ground water,
pumping and ground water outflow from the basin. The recharge is obtained in the study area using Water table fluctuation
and Tritium methods. The results of water balance study show that the total recharge in to the interstream region is of the
order of 185.25 million m 3 and discharge from the study area is of the order of 203.24 million m 3, leaving a deficit balance of −17.99 million m 3. Therefore, the present status of groundwater development in the present study area has acquired the declining trend. Thus,
the hydrogeological analysis and water balance studies shows that the groundwater development has attained a critical state
in the region. 相似文献
4.
The Grombalia aquifer (NE Tunisia) is an example of an important source of water supply for regional and national development, where the weak controls over abstraction, fertilizer application and waste disposal, coupled with limited knowledge of aquifer dynamics, is causing aquifer over-exploitation and water quality degradation. Assessing the key role of groundwater in water-resources security is therefore of paramount importance to support new actions to preserve water quality and quantity in the long-run. This study presents one of the first investigations targeted at a complete assessment of aquifer dynamics in the Grombalia aquifer. A multi-tracer hydrogeochemical and isotopic (δ 2H, δ 18O and 3H) approach was used to study the influence of seasonal variation on piezometric levels, chemical and isotopic compositions, and groundwater recharge. A total of 116 samples were collected from private wells and boreholes during three periods in a 1 year monitoring campaign (February–March 2014, September 2014 and February 2015). Results revealed the overall unsuitability of groundwater for drinking and irrigation purposes (NO 3?>?50 mg/L in 51% of the wells; EC >1,000 μS/cm in 99% of the wells). Isotopic balance coupled to piezometric investigation indicated the contribution of the shallow aquifer to deep groundwater recharge. The study also revealed the weakness of ‘business as usual’ management practices, highlighting possible solutions to tackle water-related challenges in the Grombalia region, where climate change, population growth and intensive agricultural activities have generated a large gap between demand and available water reserves, hence becoming a possible driver for social insecurity. 相似文献
5.
Jordan is an arid country with very limited water resources. Groundwater is the main source for its water supply. Mujib aquifer
is located in the central part of Jordan and is a major source of drinking water for Amman, Madaba and Karak cities. High
abstraction rates from Mujib aquifer during the previous years lead to a major decline in water levels and deterioration in
groundwater quality. Therefore, proper groundwater management of Mujib aquifer is necessary; and groundwater flow modeling
is essential for proper management. For this purpose, Modflow was used to build a groundwater flow model to simulate the behavior
of the flow system under different stresses. The model was calibrated for steady state condition by matching observed and
simulated initial head counter lines. Drawdown data for the period 1985–1995 were used to calibrate the transient model by
matching simulated drawdown with the observed one. Then, the transient model was validated by using drawdown data for the
period 1996–2002. The results of the calibrated model showed that the horizontal hydraulic conductivity of the B2/A7 aquifer
ranges between 0.001 and 40m/d. Calibrated specific yield ranges from 0.0001 to 0.15. The water balance for the steady state
condition of Mujib aquifer indicated that the total annual direct recharge is 20.4 × 10 6m 3, the total annual inflow is 13.0 × 10 6 m 3, springs discharge is 15.3 × 10 6 m 3, and total annual outflow is 18.7 × 10 6 m 3. Different scenarios were considered to predict aquifer system response under different conditions. The results of the sensitivity
analysis show that the model is highly sensitive to horizontal hydraulic conductivity and anisotropy and with lower level
to the recharge rates. Also the model is sensitive to specific yield 相似文献
6.
The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq.Water samples of groundwater and surface water were collected for two dry and wet seasons during the water year of 2011–2012.The study shows that most of the groundwater in the aquifer falls above the global meteoric water line,and all the samples fall below the Mediterranean meteoric water line,indicating that these samples are a mixture of two water types.The tritium content of these samples supports this conclusion.The overall conclusion of this study indicates that there are two sources of groundwater recharge in the studied area:the ephemeral streams(Teeb and Dewerge) and major precipitation sources.According to the tritium levels at or below one tritium unit(TU) obtained from the water,supply wells are highly confined or "not vulnerable".Overall,the 3H results imply that recent recharge has taken place during the last four to five decades.In the recharge area,the high tritium content in the southern part of the Teeb area suggests that the recharge originates from rapid infiltration of surface runoff.Therefore,the groundwater resources in the study area should be protected from contamination,because it will influence the aquifer in a relatively short period of time if any contamination enters the recharge areas of the aquifer. 相似文献
7.
Figeh watershed spring is one of the important groundwater aquifer, which is considered a major source for drinking waters
of Damascus city and countryside. The origin identification and recharge estimates of groundwater are significant components
of sustainable groundwater development in this Mountain karst aquifer of Figeh spring. During the period 2001–2009, monthly
groundwater and precipitation samples were taken and the isotopic compositions of δ 18O, δ 2H, and chloride contents were analyzed to identify groundwater origins and to estimate recharge rates. The δ 18O, δ 2H of the groundwater show that the groundwater recharge is of meteoric origin. The chloride mass balance (CMB) method was
used to quantify recharge rates of groundwater in the Mountain karst aquifer of Figeh spring. The recharge rate varies from
192 to 826 mm/year, which corresponds to 43 and 67% of the total annual rainfall. Recharge rates estimated by CMB were compared
with values obtained from other methods and were found to be in good agreement. This study can be used to develop effective
programs for groundwater management and development. 相似文献
8.
The present study assesses groundwater resources in the semiarid central Sudan, where 20 deep productive wells were installed
to supply a major city in the region, El Obeid. The wells, which has an average 20 L/s discharge each, are taping a deep semiconfined
to confined aquifer of fluvial silisiclastics deposited in the Tertiary–Pleistocene. Groundwater modeling was used as a technique
to interpret the hydrologic system in arid to semiarid central Sudan and to simulate the future influence of the project on
the hydrogeologic system. The simulation confirmed that steady-state flow conditions have been currently reached as indicated
by consistency of computed heads. It also calibrated the values of the conductivity and recharge and ensured the sustainability
of the El Obeid water supply project. A total of 3.5 × 10 7 m 3/year can be continually extracted from the deep aquifer to supply El Obeid city without endangering the groundwater resources
in the region. The decline in water level will not exceed 25 m during the first 10 years, while indefinite continuous pumping
will affect only the vicinity of the wells in a circle of 30 km diameter. Therefore, aquifer storage capacity and hydraulic
properties encourage further groundwater exploitation. The present use of groundwater is extremely lower than the present
demand, and it can potentially cover future demands without introducing significant changes to the system. The increase of
pumping cost due to the decline in head subsequent to project operation was found to be minimal and of local effect. 相似文献
9.
The Minqin Basin is at the lower reach of the Shiyang River of Gansu province in northwest China. Dramatic decline in groundwater
level has resulted from over-abstraction of groundwater since the late 1950s to satisfy increasing irrigation and other demands.
Severe water shortage led to environmental degradation. To better understand the spatial–temporal variation of groundwater
levels and to evaluate the groundwater resources in the region, a three-dimensional regional groundwater flow model was built
and calibrated under transient condition. The MODFLOW program was used and the research area was discretized as a square network
with cell size of 400 × 400 m. The model showed that the aquifer was under destructive stress, with a groundwater resource
deficit of 260 million cubic meters per year (Mm 3/year) on average. Since the inflow of surface water from the upstream basin has declined to about 100–150 Mm 3/year in recent decades, the irrigation return flow had become the main recharge and accounted for 60.6% of total recharge;
meanwhile, abstraction by pumping wells took 99.2% from the total groundwater discharge. 相似文献
10.
Urban areas are major contributors to the alteration of the local atmospheric and groundwater environment. The impact of such changes on the groundwater thermal regime is documented worldwide by elevated groundwater temperature in city centers with respect to the surrounding rural areas. This study investigates the subsurface urban heat island (SUHI) in the aquifers beneath the Milan city area in northern Italy, and assesses the natural and anthropogenic controls on groundwater temperatures within the urban area by analyzing groundwater head and temperature records acquired in the 2016–2020 period. This analysis demonstrates the occurrence of a SUHI with up to 3 °C intensity and reveals a correlation between the density of building/subsurface infrastructures and the mean annual groundwater temperature. Vertical heat fluxes to the aquifer are strongly related to the depth of the groundwater and the density of surface structures and infrastructures. The heat accumulation in the subsurface is reflected by a constant groundwater warming trend between +0.1 and?+?0.4 °C/year that leads to a gain of 25 MJ/m2 of thermal energy per year in the shallow aquifer inside the SUHI area. Future monitoring of groundwater temperatures, combined with numerical modeling of coupled groundwater flow and heat transport, will be essential to reveal what this trend is controlled by and to make predictions on the lateral and vertical extent of the groundwater SUHI in the study area. 相似文献
11.
Groundwater resource potential is the nation’s primary freshwater reserve and accounts for a large portion of potential future water supply. This study focused on quantifying the groundwater resource potential of the Upper Gilgel Gibe watershed using the water balance method. This study began by defining the project area’s boundary, reviewing previous works, and collecting valuable primary and secondary data. The analysis and interpretation of data were supported by the application of different software like ArcGIS 10.4.1. Soil water characteristics of SPAW (Soil-plant-air-water) computer model, base flow index (BFI+3.0), and the water balance model. Estimation of the areal depth of precipitation and actual evapotranspiration was carried out through the use of the isohyetal method and the water balance model and found to be 1 664.5 mm/a and 911.6 mm/a, respectively. A total water volume of 875 829 800 m 3/a is estimated to recharge the aquifer system. The present annual groundwater abstraction is estimated as 10 150 000 m 3/a. The estimated specific yield, exploitable groundwater reserve, and safe yield of the catchment are 5.9%, 520 557 000 m 3/a, and 522 768 349 m 3/a respectively. The total groundwater abstraction is much less than the recharge and the safe yield of the aquifer. The results show that there is a sufficient amount of groundwater in the study area, and the groundwater resources of the area are considered underdeveloped. 相似文献
12.
Twenty groundwater samples were collected from two different areas in Satkhira Sadar Upazila to identify the source of salinity
in deep groundwater aquifer. Most of the analyzed groundwater is of Na–Cl–HCO 3 type water. The trends of anion and cation are Cl − > HCO 3
− > NO 3
− > SO 4
2− and Na + > Ca 2+ > Mg 2+ > K +, respectively. Groundwater chemistry in the study area is mainly governed by rock dissolution and ion exchange. The dissolved
minerals in groundwater mainly come from silicate weathering. The salinity of groundwater samples varies from ~1 to ~5%, and
its source is possibly the paleo-brackish water which may be entrapped during past geologic periods. 相似文献
13.
Groundwater is a major source of water for agricultural and domestic requirements in western Uttar Pradesh. Due to increasing
agricultural requirements the abstraction of groundwater has increased manifold in the last two-to-three decades. The quaternary
alluvium hosts the aquifer in the region. The study area forms a part of Yamuna-Krishni interfluve. Although the area hosts
potential aquifers these have been adversely affected by poor management. For effective groundwater management of a basin
it is essential that a careful water balance study should be carried out. Keeping this in mind groundwater flow modelling
was attempted to simulate the behaviour of the flow system and evaluate the water balance. The groundwater flow modelling
was carried out. The horizontal flows, seepage losses from unlined canals, recharge from rainfall and irrigation return flows
were applied using different boundary packages available in Visual MODFLOW, Pro 4.1. The river-aquifer interaction was simulated
using the river boundary package. Hydraulic conductivity values were applied to specific zones and these ranged from 9.8 to
26.6m/day. Recharge due to rainfall and irrigation returns were assigned to respective zones. Pumping rates of 500m 3/day, 1000m 3/day, 1500m 3/day, 2000m 3/day and 2500m 3/day were applied to appropriate areas of the model to simulate areas of stress. The zone budget shows a water balance deficit
for the period June 2006 to June 2007. The total recharge to the study area is 160.21 million m 3 (Mcum). The groundwater draft through pumping is of the order of 233.56 Mcum, thus leaving a deficit balance of −73.35 Mcum.
The sensitivity of the model to input parameters was tested by varying the parameters of interest over a range of values,
monitoring the response of the model and determining the root mean square error of the simulated groundwater heads to the
measured heads. These analyses showed that the model is most sensitive to hydraulic conductivity and recharge parameters.
Three scenarios were considered to predict aquifer responses under varied conditions of groundwater bstraction. 相似文献
14.
Groundwater plays an important role in the economic development and ecological balance of the arid area of northwest China.
Unfortunately, human activity, for example groundwater extraction for irrigation, have resulted in excessive falls in groundwater
level, and aquifer overdraft in the oasis, disrupting the natural equilibrium of these systems. A groundwater numerical model
for Minqin oasis, an arid area of northwest China, was developed using FEFLOW software to simulate regional groundwater changes
under transient conditions. The vertical recharge and discharge (source/sink terms) of the groundwater models were determined
from land-use data and irrigation systems for the different crops in the different sub-areas. The calibrated model was used
to predict the change for the period from 2000 to 2020 under various water resources management scenarios. Simulated results
showed that under current water resources management conditions groundwater levels at Minqin oasis are in a continuous drawdown
trend and groundwater depth will be more than 30 m by 2020. Reducing the irrigation area is more effective than water-saving
irrigation to reduce groundwater decline at Minqin oasis and the annual groundwater budget would be −0.978 × 10 8 m 3. In addition, water-diversion projects can also reduce the drawdown trend of groundwater at Minqin oasis, and the groundwater
budget in the Huqu sub-area would be in zero equilibrium if the annual inflow into the oasis was enhanced to 2.51 × 10 8 m 3. Furthermore, integrative water resources management including water-diversion projects, water-saving irrigation, and reducing
the irrigation area are the most effective measures for solving groundwater problems at Minqin oasis. 相似文献
15.
This paper presents results from a site characterization and monitoring study at Karaduvar area (Mersin, SE Turkey), where
high concentrations of refined petroleum products have been detected in domestic and irrigation water wells. The saturated
and unsaturated zones in the deltaic aquifer are contaminated by large quantities of gasoline and diesel range fuel hydrocarbons
(GRHs and DRHs) released from diverse sources that include accidental spills, storage tank fires, pipeline breaks, deliberate
discharge of waste petroleum products from slop tanks and illegal tanker truck washing facilities. At the site, due to the
complex nature of the pollution sources, overlapping contaminant plumes exist and cover an area of about 0.5 km 2. In both polluted and unpolluted parts of the aquifer, monitoring of groundwater physicochemical parameters in a total of
55 sampling points was carried out between 2006 and 2007. The results show that the terminal electron acceptors (e.g. dissolved
oxygen, nitrate, Mn(IV), Fe(III), sulfate) were reduced near the source area(s) indicating presence of actively operating
biodegradation processes at the site. Close to the contaminant source area(s), conditions in the plume are highly anoxic and
reducing; where high amounts of transformation products (e.g. bicarbonate, dissolved iron, and manganese) are present in solution.
Additionally, at the site, excessive pumping, careless land use, and deliberate wastewater discharges significantly deteriorated
the quality and quantity of groundwater. Excessive groundwater pumping for industrial and agricultural uses has resulted in
substantial water level declines (2–3 m) near the coastal part where seawater intrusion threatens the groundwater resources. 相似文献
16.
The hydrodynamic groundwater data and stable isotopes of water have been used jointly for better understanding of upward leakage
and mixing processes in the Djerid aquifer system (southwestern Tunisia). The aquifer system is composed of the upper unconfined
Plio-Quaternary (PQ) aquifer, the intermediate (semi-)confined Complex Terminal (CT) aquifer and the deeper confined Continental
Intercalaire (CI) aquifer. A total of 41 groundwater samples from the CT and PQ aquifers were collected during June 2001.
The stable isotope composition of waters establishes that the CT deep groundwater (depleted as compared to present Nefta local
rainfall) is ancient water recharged during late Quaternary time. The relatively recent water in the shallow PQ aquifer is
composed of mixed water resulting from upward leakage and sporadic meteoric recharge. In order to characterize the meteoric
input signal for PQ in the study area, rainfall water samples were collected during 4 years (2000–2003) at the Nefta meteorological
station. Weighted mean values of isotopic contents with respect to rainfall amounts have been computed. Despite the short
collection period in the study area, results agree with those found in Beni Abbes (southwestern Algerian Sahara) by Fontes
on 9 years of rainfall surveillance. Stable isotopic relationships provide clear evidence of shallow PQ aquifer replenishment
by deep CT groundwater. The 18O/upward leakage rate allowed the identification of distinctive PQ waters related to CT aquifer configuration (confined in
the western part of the study area, semi-permeable in the eastern part). These trends were confirmed by the relation 18O/TDS. The isotope balance model indicated a contribution of up to 75% of the deep CT groundwater to the upper PQ aquifer
in the western study area, between Nefta and Hazoua. 相似文献
17.
Wadi El-Natrun area has recently undergone extensive urban and agricultural expansion. Due to the absence of natural surface
irrigation supplies, the only source of water in the area is the Pliocene groundwater aquifer. As a result, secondary salinization
from increased abstractions is the major threat to the groundwater aquifer. There is a dire need for efficient strategies
to ensure long-term sustainability of the area’s productive agriculture. These strategies should be based on scientific spatio-temporal
monitoring and analysis of the groundwater conditions that is also lacking. To capture the spatio-temporal variability in
groundwater conditions, field measurements of total dissolved solids, electrical conductivity, pH, temperature, and water
level as well as lab-based ionic composition were performed on 47 groundwater samples collected during 2006 and 2007. Determinations
of the hydrochemical characteristics, water types, salt assemblages, and the sodium adsorption ratio were carried out on the
samples. Reference data sets recorded in 1973 and 1997 were available for the area and were used to monitor the changes occurred
in these periods. Geographic information system (GIS) was appraised for mapping and for integrated analysis of the different
layers. Remotely sensed change detection techniques were applied to the Landsat TM and the ETM + imageries and used to highlight
the extensive reclamation and urbanization and to find key trends for the alterations in the groundwater conditions and their
spatial association with land covers. Results revealed a topographic depression-induced flow pattern, predominance of leaching
and dissolution processes, the presence of saline lakes, over-pumping from the Pliocene aquifer, and temporal changes in land
uses are the main factors combined to control the spatio-temporal variability in the groundwater. Results also clarified the
presence of two: northwestern and southeastern zones that varied distinctively in their hydrodynamic and hydrochemical characteristics.
The northwestern zone showed an average water level decline of 15 m, the water of which is brackish ( av. 2,037 mg/l) with dominant Na +, Cl − and SO 4
2− ions. The groundwater of this zone is characterized by high to very high salinity hazard and high to very high alkali hazard
and is not recommended for irrigation on soils with poor drainage and without proper management for salinity control. The
southeastern zone showed water level decline less than 2 m, the water of which is fresh ( av. 424 mg/l) with major Na +, HCO 3
−, Cl −, and SO 4
2− ions, and quality suitable for irrigation with medium to high salinity and low to medium alkali hazards. The article represents
the first step towards an integrated management of Wadi El-Natrun groundwater resources within a GIS framework. 相似文献
18.
The application of agrochemicals in crops can cause pollution of aquifers, especially those with a shallow water table and covered by thin soils; such is the case of Yucatan, Mexico. Information about the requirements and application of fertilizers to major irrigation and rainfed crops as well as the volume of water consumed in growing were used to determine the potential amount of nitrate delivered to groundwater. The research reported in this paper was conducted in the metropolitan area of the city of Merida, in Yucatán, Mexico, where groundwater plays an important role since it is the main source of supply, due to the lack of surface water in the region. In addition, the vulnerability of this aquifer is threatened by the various activities taking place in the municipalities, which emphasize agriculture, located within the groundwater basin. This activity is analyzed as a source of contamination given the concentration of NO 3 ? present in groundwater intended for human consumption. The results show that the contribution of farming that enriches the presence of nitrates in the aquifer is different for each municipality in the study area. For the ZMM, the average nutrient leaching is 44 % of the original mass applied; it could be diluted approximately 12 times, in the groundwater. 相似文献
19.
The phreatic aquifer beneath the Pampean plain, in eastern central Argentina, constitutes a relevant source of water supply
in the area. The objective of this work was to assess the significance of the cation exchange processes in the hydrochemical
evolution of this aquifer, based on a study case located in the middle and upper basin of the El Pescado creek. Results indicate
that Ca 2+/Na + exchange is the main process determining the evolution of groundwater from the recharge areas (Ca–HCO 3) towards the local discharge areas (Na–HCO 3), as well as representing a source of Na + contribution to the water in the aquifer. This hydrochemical characteristic is central to the identification of local discharge
areas within a plain environment which extends regionally. The ion exchange capacity of these discharge areas has environmental
importance, due to its influence on groundwater quality and potential groundwater uses. These results may be applied to any
aquifer sharing similar hydrogeological characteristics. 相似文献
20.
Groundwater potential map is important for environmental assessment and water resources management. In this work, a groundwater recharge potential map was established for the watershed of Oued Djelfa Hadjia in Algeria, based on new multiparameters hybrid model. The model has hydroclimatic parameters, geological settings, slope factor, and stream network density factor as inputs. The groundwater recharge estimated by the model range from 0.71 to 14 mm. The model allows delineation of potential area of recharge. The total water abstraction in Djelfa city is about of 14 hm 3; however, the calculated groundwater recharge is about 3 mm/year (min 0.71 mm and max 14 mm), which correspond to an average recharge volume of 3.9 hm 3 which mean that the aquifer is under over exploitation. 相似文献
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