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1.
Hydrochemical appraisal of groundwater and its suitability in the intensive agricultural area of Muzaffarnagar district,Uttar Pradesh,India 总被引:1,自引:0,他引:1
Muzaffarnagar is an economically rich district situated in the most fertile plains of two great rivers Ganga and Yamuna in
the Indo-gangetic plains, with agricultural land irrigated by both surface water as well as groundwater. An investigation
has been carried out to understand the hydrochemistry of the groundwater and its suitability for irrigation uses. Groundwater
in the study area is neutral to moderately alkaline in nature. Chemistry of groundwater suggests that alkaline earths (Ca + Mg)
significantly exceed the alkalis (Na + K) and weak acids exceed the strong acids (Cl + SO4), suggesting the dominance of carbonate weathering followed by silicate weathering. Majority of the groundwater samples (62%)
posses Ca–Mg–HCO3 type of hydrochemical species, followed by Ca–Na–Mg–HCO3, Na–Ca–Mg–HCO3, Ca–Mg–Na–HCO3–Cl and Na–Ca–HCO3–SO4 types. A positive high correlation (r
2 = 0.928) between Na and Cl suggests that the salinity of groundwater is due to intermixing of two or more groundwater bodies
with different hydrochemical compositions. Barring a few locations, most of the groundwater samples are suitable for irrigation
uses. Chemical fertilizers, sugar factories and anthropogenic activities are contributing to the sulphate and chloride concentrations
in the groundwater of the study area. Overexploitation of aquifers induced multi componential mixing of groundwater with agricultural
return flow waters is responsible for generating groundwater of various compositions in its lateral extent. 相似文献
2.
The sea level rise has its own-bearing on the coastal recession and hydro-environmental degradation of the River Nile Delta.
Attempts are made here to use remote sensing to detect the coastal recession in some selected parts and delineating the chemistry
of groundwater aquifers and surface water, which lie along south-mid-northern and coastal zone of the Nile Delta. Eight water
samples from groundwater monitoring wells and 13 water samples from surface water were collected and analyzed for various
hydrochemical parameters. The groundwater samples are classified into five hydrochemical facies on Hill-Piper trilinear diagram
based on the dominance of different cations and anions: facies 1: Ca–Mg–Na–HCO3–Cl–SO4 type I; facies 2: Na–Cl–HCO3 type II; facies 3: Na–Ca–Mg–Cl type III, facies 4: Ca–Na–Mg–Cl–HCO3 type IV and facies 5: Na–Mg–Cl type V. The hydrochemical facies showed that the majority of samples were enriched in sodium,
bicarbonate and chloride types and, which reflected that the sea water and tidal channel play a major role in controlling
the groundwater chemical composition in the Quaternary shallow aquifers, with a severe degradation going north of Nile Delta.
Also, the relationship between the dissolved chloride (Cl, mmol/l), as a variable, and other major ion combinations (in mmol/l)
were considered as another criterion for chemical classification system. The low and medium chloride groundwater occurs in
southern and mid Nile Delta (Classes A and B), whereas the high and very high chloride (classes D and C) almost covers the
northern parts of the Nile Delta indicating the severe effect of sea water intrusion. Other facets of hydro-environmental
degradation are reflected through monitoring the soil degradation process within the last two decades in the northern part
of Nile Delta. Land degradation was assessed by adopting new approach through the integration of GLASOD/FAO approach and Remote
Sensing/GIS techniques. The main types of human induced soil degradation observed in the studied area are salinity, alkalinity
(sodicity), compaction and water logging. On the other hand, water erosion because of sea rise is assessed. Multi-dates satellite
data from Landsat TM and ETM+ images dated 1983 and 2003 were used to detect the changes of shoreline during the last two
decades. The obtained results showed that, the eroded areas were determined as 568.20 acre; meanwhile the accreted areas were
detected as 494.61 acre during the 20-year period. 相似文献
3.
Kaveh Pazand Ardeshir Hezarkhani Yousef Ghanbari Nasrin Aghavali 《Environmental Earth Sciences》2012,65(3):871-879
The chemical analysis of 59 water wells in Meshkinshar area, Ardabil province NW of IRAN has been evaluated to determine the
hydrogeochemical processes and ion concentration background in the region. The dominated hydrochemical types are Na–SO4, Ca–HCO3, Na–HCO3 and Na–Cl in the whole area. Based on the total hardness, the groundwater is soft. According to electrical conductivity and
sodium adsorption ratio, the most dominant classes are C1–S1, C2–S1 and C3–S1. The major ion concentrations are below the
acceptable level for drinking water. The groundwater salinity hazard is medium to high but the Na hazard is low to medium
and in regard of irrigation water the quality is low to medium. So the drainage system is necessary to avoid the increase
of toxic salt concentrations. 相似文献
4.
Benony K. Kortatsi Collins K. Tay Geophrey Anornu Ebenezer Hayford Grace A. Dartey 《Environmental Geology》2008,53(8):1651-1662
Alumino-silicate mineral dissolution, cation exchange, reductive dissolution of hematite and goethite, oxidation of pyrite
and arsenopyrite are processes that influence groundwater quality in the Offin Basin. The main aim of this study was to characterise
groundwater and delineate relevant water–rock interactions that control the evolution of water quality in Offin Basin, a major
gold mining area in Ghana. Boreholes, dug wells, springs and mine drainage samples were analysed for major ions, minor and
trace elements. Major ion study results show that the groundwater is, principally, Ca–Mg–HCO3 or Na–Mg–Ca–HCO3 in character, mildly acidic and low in conductivity. Groundwater acidification is principally due to natural biogeochemical
processes. Though acidic, the groundwater has positive acid neutralising potential provided by the dissolution of alumino-silicates
and mafic rocks. Trace elements’ loading (except arsenic and iron) of groundwater is generally low. Reductive dissolution
of iron minerals in the presence of organic matter is responsible for high-iron concentration in areas underlain by granitoids.
Elsewhere pyrite and arsenopyrite oxidation is the plausible process for iron and arsenic mobilisation. Approximately 19 and
46% of the boreholes have arsenic and iron concentrations exceeding the WHO’s (Guidelines for drinking water quality. Final
task group meeting. WHO Press, World Health Organization, Geneva, 2004) maximum acceptable limits of 10 μg l−1 and 0.3 mg l−1, for drinking water. 相似文献
5.
Evaluation of hydrogeochemical processes in arsenic-contaminated alluvial aquifers in parts of Mid-Ganga Basin,Bihar, Eastern India 总被引:1,自引:1,他引:0
Dipankar Saha Sreehari S. Sarangam Shailendra N. Dwivedi Kuldeep G. Bhartariya 《Environmental Earth Sciences》2010,61(4):799-811
The study region covers 1,650 km2 of the Mid-Ganga Basin in Bihar, experiencing intensive groundwater draft. The area forms a part of the Gangetic alluvial
plain where high incidence of arsenic groundwater contamination (>50 μg/l) has recently been detected. Seventy-seven groundwater
samples have been collected and analysed for major ions, iron and arsenic. Arsenic contamination (max 620 μg/l) is confined
in hand pump zones (15–35 m) within the newer alluvium deposited during Middle Holocene to Recent age. The older alluvial
aquifers are arsenic-safe and recorded maximum concentration as 9 μg/l. Out of 12 hydrochemical facies identified, four have
been found arsenic-affected: Ca–HCO3, Mg–HCO3, Ca–Mg–HCO3 and Mg–Ca–HCO3. The geochemical evolution of groundwater, as investigated by graphical interpretation and statistical techniques (correlation,
principal component analysis) revealed that dissolution of detrital calcite, dolomite and infiltration of rainwater are the
major processes shaping the groundwater chemistry in the newer alluvium. Arsenic and iron showed strong positive correlation.
Rainfall infiltration, carrying organic matter from recently accumulated biomass from this flood-prone belt, plays a critical
role in releasing arsenic and iron present in the sediments. Geochemical evolution of groundwater in older alluvium follows
a different path, where cation-exchange has been identified as a significant process. 相似文献
6.
Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India 总被引:4,自引:3,他引:1
Geochemical processes that take place in the aquifer have played a major role in spatial and temporal variations of groundwater
quality. This study was carried out with an objective of identifying the hydrogeochemical processes that controls the groundwater
quality in a weathered hard rock aquifer in a part of Nalgonda district, Andhra Pradesh, India. Groundwater samples were collected
from 45 wells once every 2 months from March 2008 to September 2009. Chemical parameters of groundwater such as groundwater
level, EC and pH were measured insitu. The major ion concentrations such as Ca2+, Mg2+, Na+, K+, Cl−, and SO4
2− were analyzed using ion chromatograph. CO3
− and HCO3
− concentration was determined by acid–base titration. The abundance of major cation concentration in groundwater is as Na+ > Ca2+ > Mg2+ > K+ while that of anions is HCO3
− > SO4
2− > Cl− > CO3
−. Ca–HCO3, Na–Cl, Ca–Na–HCO3 and Ca–Mg–Cl are the dominant groundwater types in this area. Relation between temporal variation in groundwater level and
saturation index of minerals reveals the evaporation process. The ion-exchange process controls the concentration of ions
such as calcium, magnesium and sodium. The ionic ratio of Ca/Mg explains the contribution of calcite and dolomite to groundwater.
In general, the geochemical processes and temporal variation of groundwater in this area are influenced by evaporation processes,
ion exchange and dissolution of minerals. 相似文献
7.
The Kali-Hindon is a watershed in the most productive central Ganga plain of India. The whole area is a fertile track with
sugarcane being the principal crop. Systematic sampling was carried out to assess the source of dissolved ions, impact of
sugar factories and the quality of groundwater. Thirty-six samples were collected covering an area of 395 km2. The quality of groundwater is suitable for irrigational purposes but is rich in SO4 which is not best for human consumption. Graphical treatment of major ion chemistry helps identify six chemical types of
groundwater. All possible species such as Na–Cl, K–Cl, Na–HCO3, Na–SO4, Ca–HCO3, Mg–HCO3, Ca–SO4 and Mg–SO4 are likely to occur in the groundwater system. The most conspicuous change in chemistry of groundwater is relative enrichment
of SO4. The interpretation of data reveals that SO4 has not been acquired through water–rock interaction. The source of SO4 is anthropogenic. Sugar factories alone are responsible for this potential environmental hazard. 相似文献
8.
Chemical characteristics of groundwater in parts of mountainous region, Alvand, Hamadan, Iran 总被引:5,自引:0,他引:5
Mohsen Jalali 《Environmental Geology》2006,51(3):433-446
Eighty-seven groundwater samples have been collected from a mountainous region (Alvand, Iran) for hydrochemical investigations to understand the sources of dissolved ions and assess the chemical quality of the groundwater. Most water quality parameters are within World Health Organization acceptable limits set for drinking water. The least mineralized water is found closest to the main recharge zones and the salinity of water increased towards the north of the basin. The most prevalent water type is Ca–HCO3 followed by water types Ca–NO3, Ca–Cl, Ca–SO4 and Mg–HCO3. The Ca–NO3 water type is associated with high nitrate pollution. Agricultural and industrial activities were associated with elevated level of NO3−. Mineral dissolution/weathering of evaporites dominates the major element hydrochemistry of the area. Chemical properties of groundwater in Alvand region are controlled both by natural geochemical processes and anthropogenic activities. 相似文献
9.
Recharge source and hydrogeochemical evolution of shallow groundwater in a complex alluvial fan system,southwest of North China Plain 总被引:4,自引:0,他引:4
Fadong Li Guoying Pan Changyuan Tang Qiuying Zhang Jingjie Yu 《Environmental Geology》2008,55(5):1109-1122
Many cities around the world are developed at alluvial fans. With economic and industrial development and increase in population,
quality and quantity of groundwater are often damaged by over-exploitation in these areas. In order to realistically assess
these groundwater resources and their sustainability, it is vital to understand the recharge sources and hydrogeochemical
evolution of groundwater in alluvial fans. In March 2006, groundwater and surface water were sampled for major element analysis
and stable isotope (oxygen-18 and deuterium) compositions in Xinxiang, which is located at a complex alluvial fan system composed
of a mountainous area, Taihang Mt. alluvial fan and Yellow River alluvial fan. In the Taihang mountainous area, the groundwater
was recharged by precipitation and was characterized by Ca–HCO3 type water with depleted δ18O and δD (mean value of −8.8‰ δ18O). Along the flow path from the mountainous area to Taihang Mt. alluvial fan, the groundwater became geochemically complex
(Ca–Na–Mg–HCO3–Cl–SO4 type), and heavier δ18O and δD were observed (around −8‰ δ18O). Before the surface water with mean δ18O of −8.7‰ recharged to groundwater, it underwent isotopic enrichment in Taihang Mt. alluvial fan. Chemical mixture and ion
exchange are expected to be responsible for the chemical evolution of groundwater in Yellow River alluvial fan. Transferred
water from the Yellow River is the main source of the groundwater in the Yellow River alluvial fan in the south of the study
area, and stable isotopic compositions of the groundwater (mean value of −8.8‰ δ18O) were similar to those of transferred water (−8.9‰), increasing from the southern boundary of the study area to the distal
end of the fan. The groundwater underwent chemical evolution from Ca–HCO3, Na–HCO3, to Na–SO4. A conceptual model, integrating stiff diagrams, is used to describe the spatial variation of recharge sources, chemical
evolution, and groundwater flow paths in the complex alluvial fan aquifer system. 相似文献
10.
Eleonora S. Carol Eduardo E. Kruse Patricia C. Laurencena Adolfo Rojo Marta H. Deluchi 《Environmental Earth Sciences》2012,65(2):421-428
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 Ca2+/Na+ exchange is the main process determining the evolution of groundwater from the recharge areas (Ca–HCO3) towards the local discharge areas (Na–HCO3), 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
11.
The degradation of groundwater quality, which has been noted in the recent years, is closely connected to the intensification
of agriculture, the unreasonable use of chemical fertilizers and the excess consumption of large volumes of irrigation water.
In the hilly region of central Thessaly in Greece, which suffers the consequences of intense agricultural use, a hydrogeological
study is carried out, taking groundwater samples from springs and boreholes in the Neogene aquifers. The aim of this study
is the investigation of irrigation management, water quality and suitability for various uses (water supply, irrigation),
the degradation degree and the spatial distribution of pollutants using GIS. The following hydrochemical types prevail in
the groundwater of the study area: Ca–Mg–HCO3, Mg–Ca–Na–HCO3 and Na–HCO3. In the above shallow aquifers, especially high values of NO3
− (31.7–299.0), NH4
+ (0.12–1.11), NO2
− (0.018–0.109), PO4
3− (0.07–0.55), SO4
2− (47.5–146.5) and Cl− (24.8–146.5) are found, particularly near inhabited areas (values are in mg L−1). The water of shallow aquifers is considered unsuitable for human use due to their high polluting load, while the water
of the deeper aquifers is suitable for human consumption. Regarding water suitability for irrigation, the evaluation of SAR
(0.153–7.397) and EC (481–1,680 μS cm−1) resulted in classification category ‘C3S1’, indicating high salinity and low sodium water which can be used for irrigation
in most soils and crops with little to medium danger of development of exchangeable sodium and salinity. The statistical data
analysis, the factor analysis and the GIS application have brought out the vulnerable-problematic zones in chemical compounds
of nitrogen and phosphates. The groundwater quality degradation is localized and related exclusively to human activities.
Based on 2005 and 2008 estimates, the annual safe yield of the region’s aquifers were nearly 41.95 MCM. However, the existing
situation is that 6.37 MCM of water is over extracted from these aquifers. 相似文献
12.
Erik Espinosa María Aurora Armienta Olivia Cruz Alejandra Aguayo Nora Ceniceros 《Environmental Geology》2009,58(7):1467-1477
High arsenic (As) groundwater is widely distributed in northwestern Hetao Plain, an arid region with sluggish groundwater
flow. Observed As concentration in groundwater from wells ranges from 76 to 1,093 μg/l. Most water samples have high total
dissolved solids, with Cl and HCO3 as the dominant anions and Na as the dominant cation. The major hydrochemical types of most saline groundwaters are Na–Mg–Cl–HCO3 and Na–Mg–Cl. By contrast, fresh groundwaters generally belong to the Na–Mg–HCO3 type. High concentrations of arsenic in shallow aquifers are associated with strongly reducing conditions, as evidenced by
high concentrations of dissolved organic carbon, ammonium, as well as dissolved sulfide and Fe, dominance of arsenite, relatively
low concentrations of nitrate and sulfate, and occasionally high content of dissolved methane (CH4). High As groundwaters from different places at Hetao Plain experienced different redox processes. Fluoride is also present
in high As groundwater, ranging between 0.40 and 3.36 mg/l. Although fluorosis poses an additional health problem in the region,
it does not correlate well with As in spatial distribution. Geochemical analysis indicates that evapotranspiration is an important
process controlling the enrichment of Na and Cl, as well as trace elements such as As, B, and Br in groundwater.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
13.
Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca–HCO3 (six), Na–Cl (four), and mixed (one). The evolution of water chemistry for Ca–HCO3 spring waters was modeled by reactions of rainwater with soil organic matter, calcite, and dolomite under oxic conditions. The Na–Cl and mixed-type springs were modeled by reactions of either rainwater or Upper Floridan aquifer water with soil organic matter, calcite, and dolomite under oxic conditions and mixed with varying proportions of saline Lower Floridan aquifer water, which represented 4–53% of the total spring discharge. Multiple-tracer data—chlorofluorocarbon CFC-113, tritium (3H), helium-3 (3Hetrit), sulfur hexafluoride (SF6)—for four Ca–HCO3 spring waters were consistent with binary mixing curves representing water recharged during 1980 or 1990 mixing with an older (recharged before 1940) tracer-free component. Young-water mixing fractions ranged from 0.3 to 0.7. Tracer concentration data for two Na–Cl spring waters appear to be consistent with binary mixtures of 1990 water with older water recharged in 1965 or 1975. Nitrate-N concentrations are inversely related to apparent ages of spring waters, which indicated that elevated nitrate-N concentrations were likely contributed from recent recharge.The online version of the original article can be found at 相似文献
14.
Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs 总被引:1,自引:0,他引:1
Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca–HCO3 (six), Na–Cl (four), and mixed (one). The evolution of water chemistry for Ca–HCO3 spring waters was modeled by reactions of rainwater with soil organic matter, calcite, and dolomite under oxic conditions. The Na–Cl and mixed-type springs were modeled by reactions of either rainwater or Upper Floridan aquifer water with soil organic matter, calcite, and dolomite under oxic conditions and mixed with varying proportions of saline Lower Floridan aquifer water, which represented 4–53% of the total spring discharge. Multiple-tracer data—chlorofluorocarbon CFC-113, tritium (3H), helium-3 (3Hetrit), sulfur hexafluoride (SF6)—for four Ca–HCO3 spring waters were consistent with binary mixing curves representing water recharged during 1980 or 1990 mixing with an older (recharged before 1940) tracer-free component. Young-water mixing fractions ranged from 0.3 to 0.7. Tracer concentration data for two Na–Cl spring waters appear to be consistent with binary mixtures of 1990 water with older water recharged in 1965 or 1975. Nitrate-N concentrations are inversely related to apparent ages of spring waters, which indicated that elevated nitrate-N concentrations were likely contributed from recent recharge.An erratum to this article can be found at 相似文献
15.
Water samples collected from dug wells and tube wells from the Kurunegala District of Sri Lanka have been studied for their
major hydrogeochemical parameters to understand the chemical quality of water in the terrain. The region is composed of Precambrian
metamorphic rocks where groundwater is only available in the regolith and along weak structural discontinuities. The study
of the major chemical constituents of groundwater revealed several relationships with the aquifer lithology. Groundwater from
mafic rocks have high dissolved solids, while quartzose metaclastic rocks yield water with low dissolved solids. The study
area displays very low SO4
2− contents of the groundwater. The chloride content is higher in the dry regions and in terrains underlain by pink granite
and marble/calc gneiss while areas with marble, as expected, show high concentrations of Ca and Mg ions. The waters in the
region can be classified into non-dominant cations to Na + K dominant and Cl− and HCO3
− dominant types. Water from charnockite-bearing areas tends to have non-dominant cations and more CO3
2− + HCO3
− types. Effects such as soluble salts in the regolith, fracture intensity and climatic variations play a significant role
in the behavior of the hydrogeochemistry in the area. 相似文献
16.
Geochemistry of fluoride rich groundwater in Kolar and Tumkur Districts of Karnataka 总被引:2,自引:2,他引:0
Groundwater is a significant water resource in India for domestic, irrigation, and industrial needs. By far the most serious
natural groundwater-quality problem in India, in terms of public health, derives from high fluoride, arsenic, and iron concentrations.
Hydrogeochemical investigation of fluoride contaminated groundwater samples from Kolar and Tumkur Districts in Karnataka are
undertaken to understand the quality and potability of groundwater from the study area, the level of fluoride contamination,
the origin and geochemical mechanisms driving the fluoride enrichment. Majority of the groundwater samples did not meet the
potable water criteria as they contained excess (>1.5 mg/L) fluoride, dissolved salts (>500 mg/L) and total hardness (75–924 mg/L).
Hydrogeochemical facies of the groundwater samples suggest that rock weathering and evaporation–crystallization control the
groundwater composition in the study area with 50–67% of samples belonging to the Ca–HCO3 type and the remaining falling into the mixed Ca–Na–HCO3 or Ca–Mg–Cl type. The saturation index values indicated that the groundwater in the study area is oversaturated with respect
to calcite and under-saturated with respect to fluorite. The deficiency of calcium ion concentration in the groundwater from
calcite precipitation favors fluorite dissolution leading to excess fluoride concentration. 相似文献
17.
The total amount of groundwater resources in the middle and upper Odra River basin is 5200×103 m3/d, or about 7.7% of the disposable groundwater resources of Poland. The average modulus of groundwater resources is about
1.4 L/s/km2. Of the 180 'Major Groundwater Basins' (MGWB) in Poland, 43 are partly or totally located within the study area. The MGWB
in southwestern Poland have an average modulus of groundwater resources about 2.28 L/s/km2 and thus have abundant water resources in comparison to MGWB from other parts of the country.
Several types of mineral waters occur in the middle and upper Odra River basin. These waters are concentrated especially in
the Sudety Mountains. Carbon-dioxide waters, with yields of 414 m3/h, are the most widespread of Sudetic mineral waters.
The fresh waters of the crystalline basement have a low mineralization, commonly less than 100 mg/L; they are a HCO3–Ca–Mg or SO4–Ca–Mg type of water. Various hydrochemical compositions characterize the groundwater in sedimentary rocks. The shallow aquifers
are under risk of atmospheric pollution and anthropogenic effects. To prevent the degradation of groundwater resources in
the middle and upper Odra River basin, Critical Protection Areas have been designated within the MGWB.
Received, January 1995 Revised, May 1996, August 1997 Accepted, August 1997 相似文献
18.
Wilson Yetoh Fantong Hiroshi Satake Festus T. Aka Samuel N. Ayonghe Kazuyoshi Asai Ajit K. Mandal Andrew A. Ako 《Environmental Earth Sciences》2010,60(1):107-120
Unplanned exploitation of groundwater constitutes emerging water-related threats to MayoTsanaga River Basin. Shallow groundwater
from crystalline and detrital sediment aquifers, together with rain, dams, springs, and rivers were chemically and isotopically
investigated to appraise its evolution, recharge source and mechanisms, flow direction, and age which were used to evaluate
the groundwater susceptibility to contamination and the basin’s stage of salinization. The groundwater which is Ca–Na–HCO3 type is a chemically evolved equivalent of surface waters and rain water with Ca–Mg–Cl–SO4 chemistry. The monsoon rain recharged the groundwater preferentially at an average rate of 74 mm/year, while surface waters
recharge upon evaporation. Altitude effect of rain and springs show a similar variation of −0.4‰ for δ18O/100 m, but the springs which were recharged at 452, 679, and 773 m asl show enrichment of δ18O through evaporation by 0.8‰ corresponding to 3% of water loss during recharge. The groundwater which shows both local and
regional flow regimes gets older towards the basins` margin with coeval enrichment in F− and depletion in NO3
−. Incidentally, younger groundwaters are susceptible to anthropogenic contamination and older groundwaters are sinks of lithologenic
fluoride. The basins salinization is still at an early stage. 相似文献
19.
The Samborombon Bay wetland is located on the west margin of the Rio de la Plata estuary, in the Province of Buenos Aires,
Argentina. This paper analyses the geological, geomorphologic, soil and vegetation characteristics of the southernmost sector
of this wetland and their influence on surface water and groundwater. The study area presents three hydrologic units: coastal
dunes, sand sheets and coastal plain. Coastal dunes and sand sheets are recharge zones of high permeability with well-drained,
non-saline soils, and a few surface water flows. Changes in the water table are related to rainfall. Groundwater in coastal
dunes is Ca–Mg–HCO3 to Na–HCO3, and of low salinity (590 mg/l). Groundwater in sand sheets is mainly Na–HCO3 with a salinity of about 1,020 mg/l. The coastal plain exhibits medium to low permeability sediments, with submerged saline
soils poorly drained. Groundwater is Na–Cl with a mean salinity of 16,502 mg/l. A surface hydrological network develops in
the coastal plain. Surface water levels near the shoreline are affected by tidal fluctuations; far from the shoreline water
accumulates because of poor drainage. Both sectors have Na–Cl water, but the former is more saline. Human intervention and
sea level rise may affect the wetland severely. 相似文献
20.
Integrated hydrochemical assessment of the Quaternary alluvial aquifer of the Guadalquivir River, southern Spain 总被引:2,自引:0,他引:2
M. Lorite-Herrera R. Jimnez-Espinosa J. Jimnez-Milln K.M. Hiscock 《Applied Geochemistry》2008,23(8):2040-2054
The alluvial aquifer of the Guadalquivir River comprises shallow Quaternary deposits located in the central-eastern part of the Province of Jaén in southern Spain, where groundwater resources are used mainly for crop irrigation in an important agricultural area. In order to establish the baseline hydrochemical conditions and processes determining the groundwater quality, groundwater and river water samples were collected as part of an integrated investigation that coupled multivariate statistical analysis with hydrochemical methods to identify and interpret the groundwater chemistry of the aquifer system. Three main hydrochemical types (Mg–Ca–HCO3, Ca–Mg–SO4–HCO3–Cl and Na–Ca–Mg–Cl–SO4) were identified. Further interpretation, using R-mode principal components analysis (PCA) conducted with 13 hydrochemical variables, identified two principal components which explain ⅔ of the variance in the original data. In combination with the hydrochemical interpretation, mineralogical analyses of the aquifer sediment together with inverse geochemical modelling using NETPATH showed that dedolomitization (calcite precipitation and dolomite dissolution driven by gypsum dissolution) is the principal hydrochemical process controlling the regional groundwater chemistry. Other processes such as silicate weathering, ion exchange, mixing between river water and groundwater, and agricultural practices also affect the groundwater chemistry. 相似文献