Search

Groundwater is the major primary source of drinking and irrigation water for nearly 500 million inhabitants in both rural and urban areas of the Ganga Alluvial Plain (GAP) in India. Indiscriminate pumping of groundwater primarily from the shallow parts of the alluvial aquifer system is leading to rapid decline in water tables. It is expected that in coming years, the stress on groundwater will only increase due to steadily rising urbanization and additional demands for water and land, as well as by impending weather anomalies and shifts in availability of water during seasons when demands for irrigation and ecological needs are high. In the present study, Inverse Distance Weighted (IDW) interpolation method is used using pre- and post-monsoon groundwater levels from 764 observatory wells and peizometers to assess the trends of declining groundwater in the Gomti River Basin (GRB) during 2005 to 2015. Groundwater potential zone maps were composed using water depths data and Cartosat-1 satellite images delineating the area under rising and falling groundwater tables. The loss of shallow groundwater was clearly visible during the 2005–2015 periods. The decline is attributed to intensive irrigation from groundwater as well as peri-urban growth around the state capital. This study can apprise the planners and local administrators of the effects of irrigation and urbanization on the groundwater regime in the fast growing regions of the basin. [ABSTRACT FROM AUTHOR]

Elemental compositions of water, and surface and subsurface soils indicate characterization and mobilization of elements within soil profiles. The chemical variations of groundwater (n = 21) and surface and subsurface soils (n = 18 each) of the Polpithigama area were examined to determine elemental spatial variation in the area. Physico-chemical parameters (pH, electrical conductivity (EC), dissolved oxygen (DO), oxygen reduction potential (ORP)) and NO3−, PO42−, Mn, Fe, and F were analyzed for the water samples in the field using field test kits. Soil samples were analyzed using X-ray fluorescence for 22 major and trace elements. Iron, Mn, NO3−, and PO42− concentrations in water are lower than the threshold values of WHO. The fluoride content was increased with high elevation even within a short distance. The fluoride and phosphate are highly variable between the soil layers and are preferably retained in the surface soil. The vertical variation is resulted by intensive weathering under tropical conditions, mobility of ions, variation of elements, and variation of soil constituents such as different contents of organic matter and clay content consisting of high total sulfur (TS) contents. Migration of some ions to the groundwaters of the area is possible due to high mobility of elements and thus the compositions of some elements show variations in the surface and subsurface soils. [ABSTRACT FROM AUTHOR]

Groundwater flow modeling was carried out to assess current and to project future groundwater scenarios in highly populated and water stressed region of Ganges sub-basin. Both the urban and rural densely populated areas of Ganges sub-basin was selected to capture the groundwater usage patterns in these watersheds. The groundwater system geologically consists of sand and clay layers. However, the layers are not stratified and has highly variable thicknesses and at places various layers disappears. Therefore, a 3D model was prepared so that variability in the vertical direction is also taken care. The study area modeled is divided into grids with 37 rows and 37 columns with 1 km size. The month of June 2016 was taken to perform the steady-state simulation as June has the lowest groundwater levels as well as the minimum stress on the aquifer. Subsequently the Transient state calibration was carried out from June 2016 to November 2018. A good match is obtained between calculated and observed heads in steady state conditions after a rigorous calibration with RMS error as 1.822 m. The sensitivity analysis of the model shows that the model is more sensitive to input parameters like recharge and hydraulic conductivity. The prediction scenarios were developed for a period of 10 years from 2018 to 2028 using the local conditions of groundwater utilization as well as projected rainfall. The rise in water level in rural areas is observed resulting from artificial sources like canal recharge and irrigation return flows from irrigated lands. The rise in groundwater level is in the range of 0.13–0.31 m/year in Scenario I and 0.11–0.47 m/year in Scenario II. The decline in groundwater levels is noticed in urban areas which are a result of heavy domestic and industrial groundwater withdrawal and absence of recharge areas. The decline in groundwater level is in the range of 0.12–0.31 m/year in Scenario I and 0.24–0.33 m/year in Scenario II. [ABSTRACT FROM AUTHOR]

Groundwater is considered as the primary source of urban water supply in major cities of the world. Rapid industrial development and increase in population have deteriorated the quality of groundwater of Faisalabad, Pakistan. The overexploitation of groundwater caused depletion of groundwater level, and evaluation of groundwater status has become critical for the sustainability of urban water supply. This paper's main objective is to present the overexploitation effect on aquifer based on historical and existing groundwater situations, and future groundwater conditions are projected based on six different scenarios. The transient groundwater model was developed coupling Groundwater Vista with MODFLOW to simulate the impact of groundwater pumping on the Chenab River's bed well field. Water table was calibrated and validated for 13 years (1992 to 2005) and 5 years (2006 to 2010), respectively, and model performance evaluation indicators, represented the model's reliability for further application. Moreover, the steep gradient of the groundwater head contour was observed in the well-field's southern area, and resultantly steady-state condition has been established. Future urban water supply conditions were projected by implementing six scenarios based on the groundwater pumping system's existing capacity for 2030. With 90% pumping capacity, the system forecasted a decline in the water table from 0.6 to 1.3 m year−1, respectively. Groundwater recharge conditions evaluated and forecast results represented a drop of 0.45 m year−1 till 2030 during optimization. Factual and detailed information is projected for future scenarios based on existing developed models that explain groundwater pumping strategies for sustainable urban water supply management. [ABSTRACT FROM AUTHOR]

The objective of the study is to develop conjunctive use model for the effective utilization of groundwater (GW) and canal water so as to maximize the net benefit. In this study, it has been shown that canal water can be saved up to a greater extent just by using GW as an additional source. The developed conjunctive use model is being solved by teaching-learning-based optimization (TLBO) algorithm. To validate TLBO algorithm results, LINGO is being used. It has been found that both the algorithms give nearly the same results. From results, it has been found that the sugarcane cultivation has to be increased to recompense net return. Increased net benefit is about 4-7%. Optimization results show that to maximize the net benefit all other crop cultivation (except sugarcane) has to be reduced by 7-12%. Overall net benefit is increased to 5-10% in any given season. From the results, it has been concluded that, by utilizing both canal water and GW, canal water can be saved up to 55% in hot season, 27% in rabi season and 22% in kharif season. [ABSTRACT FROM AUTHOR]

This work applied environmental isotope techniques to validate the results of previous studies on recharge sources in a rural area in central Chile (34.3° S and 71.3° W) and discern the origin of nitrate contamination in wells. Stream water and groundwater samples were taken during three surveys, two during spring snowmelt and one in low-water conditions. Chemical analyses included major cations and anions, isotope analyses included 18O-H2O; 2H-H20; 3H-H20; 18O-NO3− and 15N-NO3−. The stable isotope data show that surface water and deep groundwater present depleted isotope values associated with recharge from the Andes Mountains and that shallow groundwater has more enriched isotope values that reflect the contribution of local recharge from rainwater infiltration. Depleted isotope values observed in shallow groundwater show the effect of recirculated river water used for irrigation. These results are consistent with the conceptual groundwater model developed in previous studies. Some wells have nitrate concentrations above the allowable limit for drinking water. The stable nitrogen isotopes indicate that nitrate is associated mainly with urea and ammoniacal fertilizers, and nitrate is attenuated by denitrification. The results of this study are relevant to improving management of groundwater resources used for drinking water. [ABSTRACT FROM AUTHOR]

The groundwater crisis in northwestern India is the result of over-exploitation of groundwater resources for irrigation. The Government of India has targeted a 20 percent improvement in irrigation groundwater use efficiency. In this perspective, and using a regional-scale calibrated and validated three-dimensional groundwater flow model, this article provides the first forecasts of water levels in the study area up to the year 2028, both with and without this improvement in use efficiency. Future water levels without any mitigation efforts are anticipated to decline by up to 2.8 m/year in some areas. A simulation with a 20 percent reduction in groundwater abstraction shows spatially varied aquifer responses. Tangible results are visible in a decade, and the water-level decline rates decrease by 36–67 percent in over-exploited areas. Although increasing irrigation use efficiency provides tangible benefits, an integrated approach to agricultural water management practice that incorporates use efficiency along with other measures like water-efficient cropping patterns and rainwater harvesting may yield better results in a shorter period. [ABSTRACT FROM AUTHOR]

The over-extraction of groundwater from thin fresh groundwater lenses is a threat to the livelihood of farmers in the Lower Indus Basin (LIB). It is essential to monitor and regulate this pumping to sustain fresh groundwater lenses. In this study, we applied a modelling approach in combination with geostatistical analysis to identify the critical locations to monitor the groundwater levels for sustaining fresh groundwater in the LIB. Our approach included four steps: (i) simulating temporal heads using a calibrated hydrogeological model; (ii) sampling monitoring locations using a hexagonal pattern of sampling; (iii) applying principal component analysis (PCA) of the temporal head observations, and selecting high scoring locations from the PCA; and (iv) minimizing the observation points to represent the water level contours. The calibrated model was able to replicate the hydro-dynamic behavior of the study area, with a root mean square of 0.95 and an absolute residual mean of 0.74 m. The hexagonal pattern of spatial sampling resulted in a 195 point network, but PCA reduced this network to 135 points and contour classification reduced it even further to 59 points. The 195, 135, and 59 point networks represented the water levels with average standard errors of 0.098, 0.318, and 0.610 m, respectively. Long-term simulations with increased pumping showed that the water levels would best be assessed by 195 monitoring points, although 135 and 59 points would represent the depleting area but would not capture the water logging area. [ABSTRACT FROM AUTHOR]

The Gravity Recovery and Climate Experiment (GRACE) twin satellite provides an efficient method of assessing groundwater anomalies by measuring variations in terrestrial water storage (TWS) and its anomalies (TWSA). The TWS is the sum of all forms of water such as groundwater, soil moisture, surface water and snow water equivalent. We used CSR RL05 Mascon solutions (http://www.csr.utexas.edu/grace) to estimate the seasonal level regional scale groundwater depletion rates across India between 2002 and 2016. The groundwater storage showed substantial spatial variations at the seasonal scale. At the regional scale, our analysis revealed the steepest decline in the northwest and northeast regions of India. This has been caused by a significant increase of land under well and tube‐well irrigation. Furthermore, the rapid rates of urbanization associated with a lower recharge of the groundwater table due to increased runoff also contributed to depleted groundwaters across India. [ABSTRACT FROM AUTHOR]

Hydrochemical processes have been evaluated for the groundwater regime in Trans-Yamuna alluvial aquifer, Palwal District, Haryana. The groundwater belongs to the Na+–Mg+2 and Cl−–SO4−2 facies, and solute acquisition processes indicated that the rock weathering/evaporation is a major mechanism that characterizes the hydrochemistry. It is also indicated that dissolution and reverse ion exchange processes are playing a major role in determining the groundwater chemistry in the study area. The varied climate in Ganga plains is responsible for the importance of different hydrogeochemical processes that impact on hydrochemistry of groundwater. Groundwater quality parameters were tested for drinking and irrigation purposes. Water quality index shows that 13%, 31%, 34% and 21% fall in good, poor, very poor and unsuitable water category, respectively, for drinking purposes. On the basis of SAR and Na%, the groundwater indicated that it is safe for irrigation purposes. But high TDS of few samples suggested the salinity hazard while using it for irrigation purposes for a longer period. [ABSTRACT FROM AUTHOR]

Seepage from unlined irrigation canals is a signi ficant source of groundwater recharge for shallow aquifers in many parts of the world, especially in arid and semi-arid regions such as Egypt. This is the case for Ismailia canal, the most important branch canal of the River Nile in Egypt, which suffers seepage losses along its entire length (129.5 km). Groundwater modeling was performed using MODFLOW to determine the effect of lining of four sections of the canal, with a total length of 61 km on the water balance of the underlying unconsolidated porous-medium aquifer and to optimize the locations of the lined sections. The model was developed using existing hydrogeological data from the area and was calibrated using water table data for the period 2004–2013. The simulation results indicated that the optimum locations of lined sections to minimize the seepage losses are located at distances along the canal from 19 to 45 kms, from 70 to 93 km and from 109 to 117 km from the head regulator at km (0.00) near Cairo. The minimum seepage losses, in that case, is equal to 7.3% of the canal total discharge. The modeling also indicated that seepage from the unlined canal provides about 3.5 million m3/day recharge to the underlying aquifer and these seepage losses represent about 21.6% of the canal total discharge. The optimum lining of the canal reduced the recharge to the aquifer by 65% (from 3,426,500 to 1,199,500 m3/day. The discharge from the model.domain (outward the boundaries) and the added recharge to the aquifer storage reduced by 50% from about 4.0 million m3/day to about 2.02 million m3/day between 2016 and 2021. [ABSTRACT FROM AUTHOR]

In order to understand the hydrogeochemistry of Mathura city, western Uttar Pradesh a total of 92, 34 and 22 groundwater samples were collected from shallow, intermediate and deep wells during post-monsoon 2017 and pre-monsoon 2018 respectively and analyzed for major cations and anions. The groundwater of the study area is found to be alkaline in nature and is categorized as hard to very hard water type. Dominant facies deciphered from Piper's trilinear diagram of shallow, intermediate wells are Na-K-Cl-SO4 and Ca-Mg-Cl-SO4 while deep well samples are Ca-Mg-Cl-SO4 type facies in post-monsoon 2017. During pre-monsoon 2018, the ionic facies for shallow, intermediate and deep well samples is Na-K-Cl-SO4 type with the exception of 7 samples of shallow well which shows Ca-Mg-Cl-SO4 type facies. Based on the water quality index (WQI) classification, majority of samples of shallow, intermediate and deep well fall in poor water category in both seasons. According to pollution index of groundwater (PIG) classification, majority of samples of all three depths showed low to moderate pollution in both the seasons. Saturation indices of minerals was also calculated by employing geochemical program PHREEQC. Groundwater at shallow depth possesses excess concentration of Ca, Na, K, and SO4, followed by intermediate and deeper depth samples of both seasons. Trace elements like As, Mo, Sr, and Zn show higher concentration in shallow depth samples followed by intermediate and deeper depth samples, except As which shows a reverse trend. This demonstrates that the groundwater from shallow wells is definitely more vulnerable to contamination. The study has revealed poor groundwater quality of Mathura city and noticeable influence of urbanization and industrialization on water quality. [ABSTRACT FROM AUTHOR]

The groundwater build-up in recent years in Gujarat state of western India, which has been known for aquifer exploitation for many decades, had caught the attention of researchers worldwide. This article analyses the various parameters that can influence groundwater behaviour and argues that the recent water level rise in the region is due to large-scale import of surface water from the Sardar Sarovar project for irrigation along with greater rainfall. The earlier works argued that the improvement in groundwater condition is because of the massive, government-sponsored water harvesting work and the introduction of a policy to restrict power supply for well irrigation. [ABSTRACT FROM AUTHOR]

Parametric water quality indexing (WQI) helps integrate the interwoven effects of independent parameters which may enhance or impair the desirable physico-chemical and biological characteristics of both surface waters and groundwater reserves. Monsoon and post-monsoon status of the distribution of such parameters will give an insight on improvising the qualities of water for multiple usages in the vicinity of a tank and its influential area on groundwater contamination. A typical system tank in Coimbatore urban reach of the Noyyal river was studied by using GIS applications. The test values of all parameters considered were subjected to indexing for water quality grades inflicted by the presence of contaminants. On a 1 to 5 gradation, the study area was found to have a weighted mean water quality index of 2.34 and 2.35 for tank surface water during the monsoon and post-monsoon periods, respectively. In case of ground water sampling, the same was found to be 2.17 and 2.19 for the respective situations. The overall hazard rating was characterized under medium to high, warranting quarantine measures to safeguard the water quality standards for multiple uses in the study locality, pinning the eyes on dissolved oxygen improvements, turbidity control mechanisms, alkalinity amendments and moderations of hardness prevailing as high hazard indicators. The pre-monsoon season ratings were nearing the critical conditions at overall ratings ranging from 3.03 to 2.65 (high to severe) for surface and groundwater, respectively. [ABSTRACT FROM AUTHOR]

Bachtouli, S. and Comte, J.-C., 2019. Regional-scale analysis of the effect of managed aquifer recharge on saltwater intrusion in irrigated coastal aquifers: Long-term groundwater observations and model simulations in NE Tunisia. Journal of Coastal Research, 35(1), 91–109. Coconut Creek (Florida), ISSN 0749-0208. In overexploited coastal aquifers threatened or affected by saline intrusion, managed aquifer recharge (MAR) is increasingly applied in the aim of maintaining or recovering freshwater quantity and quality. The long-term regionalscale effectiveness of MAR, however, lacks field examples. The Korba coastal aquifer (Tunisia) has been increasingly overexploited since the 1960s and intensively studied over the last few decades. Groundwater abstraction has resulted in a decline of groundwater levels and a dramatic increase in salinity through both lateral seawater intrusion and shallow salinization from irrigation. MAR strategies, including freshwater injection wells and sewage-water infiltration basins, have been progressively implemented since 1990. Using 50 years of groundwater head and salinity records, a regional three-dimensional numerical groundwater model is calibrated to study the spatiotemporal dynamics of groundwater salinization including the past and future impact of the MAR operations. Results suggest that lateral seawater intrusion from the coast and shallow infiltration of evapoconcentrated saline irrigation water are the two interlinked dominant regional processes of groundwater salinization, equivalent in magnitude. In accordance with the groundwater observations, simulated historical MAR operations are shown to have contributed to slowdown and stabilized the regional salinization, which contrasts with the steady rise that is obtained in the hypothetical absence of MAR. The future MAR simulation scenarios suggest that spatial management of irrigation supplies and injection points from dam freshwater has a potential for further reducing the salinization of shallow groundwater and potentially reversing the inland progression of the seawater front. Further works should look at reconciling modelling recommendations with management practice options. [ABSTRACT FROM AUTHOR]

At least 50% of India's total irrigated area is dependent on groundwater and there are wide variations in terms of its access and usage. Of late, over-exploitation of groundwater and falling water table levels across the country has become a cause of concern. Though there are many strategies to arrest this trend, crop diversification and water use efficiency stand out as they reduce farmer's risk besides improving resource use efficiency and scaling down cultivation cost. In this context, the present study was conducted in the groundwater exploitation areas of Saurashtra region, Gujarat to understand the extent and feasibility of crop diversification and water-use efficiency. For this study, Harfindahl and Margalef indices were worked out and water use efficiency (WUE) was estimated. The findings revealed Harfindahl indices between 0.65 and 0.91 indicating lesser preference for crop diversification in the study area. Further, Margalef Index (MI) of cotton (1.10) and groundnut (0.52) indicated higher concentration of these crops. The water consumption levels (in HP hrs /ha) for cotton (291.94 to 1050.97) and groundnut (209.85 to 424.03) were found to be highly varying among the farmers. Similarly, average WUE (in HP hrs/qtl) was 35.10 (groundnut) and 56.98 (cotton). Though the WUE of Chilly crop (8.49) was found higher, its average gross returns (Rs. 19,222/ha) was observed to be lower than that of groundnut (Rs. 25,081/ha) and cotton (Rs. 54,373/ha). Accordingly, the study suggests that income, price and adaptation factors are crucial for successful adoption of crop diversification and WUE leading to scaled down risks, costs and boost farm profitability, which in turn may result in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Water quality modeling is increasingly recognized as a useful tool for obtaining valuable information for optimal water quality management. In this study, the free software QUAL2Kw was used to evaluate the impacts of agricultural nitrogen (N) excess on river nitrate (NO3-N) concentrations. We explored the possibility to use QUAL2Kw in order to back calculate the exchange of water and N from the groundwater to the Oglio River, northern Italy, which drains a heavily irrigated and fertilized agricultural land. Along the river course water monitoring activities carried out in the dry, summer period revealed steep increases of NO3-N in different sectors, by up to 2 orders of magnitude, not explained by any significant point inputs. Such increases suggest the occurrence of large water exchange with nitrate-polluted groundwater and diffuse inputs. In turn, groundwater pollution is due to high N excess in the watershed (~200 kg N ha-1 yr-1), flood-based irrigation techniques and soil permeability. The QUAL2Kw model was calibrated using the average of 2 years' data collected in winter 2010 and 2011 and validated using the data of winter 2012. To minimize the error between simulation results and measured data, the constants of inorganic suspended solid (ISS), ammonium (NH4-N), nitrate and organic N were calibrated. The calibration and validation results showed a good correspondence between the calculated and measured values for most of water-quality variables. QUAL2Kw was then run separately with three years' summer data (2009, 2010 and 2011), and large gaps were found between the measured and predicted values of discharge, electrical conductivity, NO3-N and total N. Such gaps are discussed in terms of river-groundwater interactions, limited to the summer period and following irrigation by flooding, rise of the groundwater table and vertical transport of N. The gaps allowed to back calculate the volumes of water and the amount of N exchanged. The total load of NO3-N entering into the river from groundwater was estimated in 25.17, 25.63 and 29.89 ton per day for NO3-N in 2009, 2010 and 2011, respectively. Similar results were obtained in another study based on mass balance of N isotopes. The combination of experimental and QUAL2Kw modelled data proved to be a simple, low cost but effective tool in the estimation of NO3-N exchange between the surface and groundwater. [ABSTRACT FROM AUTHOR]

ABSTRACT Naseem, S.; Husain, V., and Bano, S., 2018. Origin of salinity and other constituents in Indus deltaic plain groundwater, Thatta District, Pakistan. Physico-chemical and microbiological analyses of 32 groundwater samples from the Sujawal and Makli areas of Thatta District, Sindh Province, Pakistan, were carried out to reveal the source of major ions and high salinity. Data reveal that aquifers in the study area show high salinity due to various geochemical phenomena, including cation exchange, mineral dissolution, evaporation, seawater intrusion, and anthropogenic activities. Shallow wells in the area are highly polluted due to unlined sanitation ponds, fish ponds, and waste dumps, as shown by microbiological data. Minerals found in subsurface soil are quartz, calcite, calcian-albite, muscovite, and phlogopite, which could be sources of high salinity and fluoride in groundwater. High arsenic in subsurface soil can be related with Holocene aquifers. However, the alkaline pH and oxic nature of the aquifers are not favorable for the release of arsenic in the groundwater of the study area. Therefore, most of the aquifers in the area are free from arsenic. [ABSTRACT FROM AUTHOR]

The analysis of hydrogeological problems arising in bog watering by methods enabling the depth to groundwater table to be controlled was used to develop a method for estimating the efficiency of such control when data for directly solving groundwater flow problems are lacking. The effect of nonmonotone dependence of the rate of groundwater level rise on the hydraulic conductivity of peat underlain by high-permeability sand rocks is described. This effect is shown to be significant in assessing the potentialities of the operational control of groundwater level in bog massifs with this type of geological structure. [ABSTRACT FROM AUTHOR]

The contradiction between the freshwater shortage and the large demand of freshwater by irrigation was the key point in cultivated lowland area of North China Plain. Water transfer project brings fresh water from water resource‐rich area to water shortage area, which can in turn change the hydrological cycle in this region. Major ions and stable isotopes were used to study the temporal variations of interaction between surface water and groundwater in a hydrological year after a water transfer event in November 2014. Irrigation canal received transferred Yellow River, with 2.9% loss by evaporation during water transfer process. The effect of transferred water on shallow groundwater decreased with increasing distance from the irrigation canal. Pit pond without water transfer receives groundwater discharge. During dry season after water transfer event, shallow groundwater near the irrigation canal was recharged by lateral seepage and deep percolation of irrigation, whereas shallow groundwater far from irrigation canal was recharged by deep percolation of deep groundwater irrigation. Canal water lost by evaporation was 2.7–17.4%. Influence of water transfer gradually disappeared until March as the water usage of agricultural irrigation increased. In the dry season, groundwater discharged to irrigation canal and pond; 2.2–31.6% canal water and 11.3–20.0% pond water were lost by evaporation. In the rainy season (June to September), surface water was fed mainly by precipitation and surface run‐off, whereas groundwater was recharged by infiltration of precipitation. The two‐end member mix model showed that the mixing ratio of precipitation in pond and irrigation canal were 73–83.4% (except one pond with 28.1%) and 77.3–99.9%, respectively. Transferred water and precipitation were the important recharge sources for shallow groundwater, which decreased groundwater salinity in cultivated lowland area of North China Plain. With the temporary and spatial limitation of water transfer effects, increased water transfer amounts and frequency may be an effective way of mitigating regional water shortage. In addition, reducing the evaporation of surface water is also an important way to increase the utilization of transfer water. [ABSTRACT FROM AUTHOR]

We investigated the impacts of on-site sanitation systems to local groundwater. In this year-long study, we monitored the response of faecal contamination levels to hydroclimatological factors including rainfall and groundwater table. Concentration of faecal indicators—E. coli (ESC), Enterococcus (ENT), nitrate—in thirteen pairs of shallow and deep wells were determined every 7-14 days. All samples from shallow wells were tested positive for faecal contamination (ESC and ENT > 1 MPN/100 mL) but concentration varies. A maximum of 24,000 MPN/100 mL were recorded in some shallow wells. Water from deep wells showed lower susceptibility to contamination with only 4 and 23% of samples tested positive for ESC and ENT, respectively. Concentrations of ESC and ENT were lower too, with a maximum of 5 MPN/100 mL and 28 MPN/100 mL, respectively. Fluctuation in contamination among the wells was described by four archetypal responses to hydroclimatological forcing: (i) flushing during the onset of wet season, (ii) dilution over the course of the wet season, (iii) concentration during the dry season, and (iv) synoptic response to storms. Previous studies attempting to link the prevalence of faecal/waterborne diseases and temporal factors (e.g., dry vs wet season) have produced differing outcomes. Our study may help explain the relevant hydrological mechanisms leading to these varying observations. Presently, most communities in Thailand have access to ‘improved’ sanitation systems. However, due to the unsustainable implementation of these systems, the otherwise viable drinking-water resources in the form of the abundant local groundwater has become a genuine health hazard. [ABSTRACT FROM AUTHOR]

Dwarka River basin in Birbhum, West Bengal (India), is an agriculture-dominated area where groundwater plays a crucial role. The basin experiences seasonal water stress conditions with a scarcity of surface water. In the presented study, delineation of groundwater potential zones (GWPZs) is carried out using a geospatial multi-influencing factor technique. Geology, geomorphology, soil type, land use/land cover, rainfall, lineament and fault density, drainage density, slope, and elevation of the study area were considered for the delineation of GWPZs in the study area. About 9.3, 71.9 and 18.8% of the study area falls within good, moderate and poor groundwater potential zones, respectively. The potential groundwater yield data corroborate the outcome of the model, with maximum yield in the older floodplain and minimum yield in the hard-rock terrains in the western and south-western regions. Validation of the GWPZs using the yield of 148 wells shows very high accuracy of the model prediction, i.e., 89.1% on superimposition and 85.1 and 81.3% on success and prediction rates, respectively. Measurement of the seasonal water-table fluctuation with a multiplicative model of time series for predicting the short-term trend of the water table, followed by chi-square analysis between the predicted and observed water-table depth, indicates a trend of falling groundwater levels, with a 5% level of significance and a p-value of 0.233. The rainfall pattern for the last 3 years of the study shows a moderately positive correlation (R2 = 0.308) with the average water-table depth in the study area. [ABSTRACT FROM AUTHOR]

In drylands, groundwater is often the sole source of freshwater for industrial, domestic and agricultural uses, while concurrently supporting ecosystems. Many dryland aquifers are becoming depleted due to over-pumping and a lack of natural recharge, resulting in loss of storage and future water supplies, water-level declines that reduce access to freshwater, water quality problems, and, in extreme cases, geologic hazards. Conservation is often proposed as a strategy for managing groundwater to reduce or reverse the depletion, although there is a need to better understand its potential effectiveness and benefits at the local scale. This study assesses the impact of water-conservation planning strategies on groundwater resources in the Wadi El Natrun (WEN) area of northern Egypt. WEN has been subjected to groundwater depletion and quality degradation since the 1990s, attributed to agricultural and industrial groundwater usage. Initiatives have been proposed to increase the sustainability of the groundwater resource in the study area, but they have yet to be evaluated. Simultaneously, there are also proposals to increase the extent of arable land and thus demand for freshwater. In this study, three water management scenarios are developed and assessed to the 2060s for their impact on groundwater resources using a hydrogeologic model. Results demonstrate that demand management implemented through an optimized irrigation and crop rotation strategy has the greatest potential to significantly reduce risk of groundwater depletion compared to the other two scenarios—“business as usual” and “30% water-use reduction”—that were evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Groundwater beneath the alluvial plain of the Indus River, Pakistan, is reported to be widely polluted by arsenic (As) and to adversely affect human health. In 79 groundwaters reported here from the lower Indus River plain in southern Sindh Province, concentrations of As exceeded the WHO guideline value for drinking water of 10 μg/L in 38%, with 22% exceeding 50 μg/L, Pakistan's guideline value. The As pollution is caused by microbially‐mediated reductive dissolution of sedimentary iron oxyhydroxides in anoxic groundwaters; oxic groundwaters contain <10 μg/L of As. In the upper Indus River plain, in Punjab Province, localized As pollution of groundwater occurs by alkali desorption as a consequence of ion exchange in groundwater, possibly supplemented by the use for irrigation of groundwater that has suffered ion exchange in the aquifer and so has values >0 for residual sodium carbonate. In the field area in southern Sindh, concentrations of Mn in groundwater exceed 0.4 mg/L in 11% of groundwaters, with a maximum of 0.7 mg/L, as a result of reduction of sedimentary manganese oxides. Other trace elements pose little or no threat to human health. Salinities in groundwaters range from fresh to saline (electrical conductivity up to 6 mS/cm). High salinities result from local inputs of waste water from unsewered sanitation but mainly from evaporation/evapotranspiration of canal water and groundwater used for irrigation. The process does not concentrate As in the groundwater owing to sorption of As to soils. Ion exchange exerts a control on concentrations of Na, Ca, and B but not directly on As. High values of Cl/Br mass ratios (most ≫288, the marine value) reflect the pervasive influence on groundwater of sewage‐contaminated water from irrigation canals through seepage loss and deep percolation of irrigation water, with additional, well‐specific, contributions from unsewered sanitation. [ABSTRACT FROM AUTHOR]

The use of inverse methods allow efficient model calibration. This study employs PEST to calibrate a large catchment scale transient flow model. Results are demonstrated by comparing manually calibrated approaches with the automated approach. An advanced Tikhonov regularization algorithm was employed for carrying out the automated pilot point (PP) method. The results indicate that automated PP is more flexible and robust as compared to other approaches. Different statistical indicators show that this method yields reliable calibration as values of coefficient of determination (R2) range from 0.98 to 0.99, Nash Sutcliffe efficiency (ME) range from 0.964 to 0.976, and root mean square errors (RMSE) range from 1.68 m to 1.23 m, for manual and automated approaches, respectively. Validation results of automated PP show ME as 0.969 and RMSE as 1.31 m. The results of output sensitivity suggest that hydraulic conductivity is a more influential parameter. Considering the limitations of the current study, it is recommended to perform global sensitivity and linear uncertainty analysis for the better estimation of the modelling results. [ABSTRACT FROM AUTHOR]

Birbhum district in West Bengal, India, is one of the most severely affected districts by fluoride-contaminated groundwater. Fluoride content as high as 20.4 mg/L has been reported. Several cases of fluoride-related disorder such as dental fluorosis and skeletal fluorosis have been reported to be endemic in the district. Proper management of groundwater is very crucial. This contribution has been carried out for delineating potential fluoride-contaminated zones (PFCZ) in Birbhum district with the implementation of weighted overlay analysis in GIS environment. Twelve different potentially influential environmental parameters are integrated and evaluated. The final output map was categorised into two subclasses, i.e. 'low' and 'high', where the low region represents fluoride concentration of 1.5 mg/L and below and the high region represents fluoride concentration above 1.5 mg/L. The outcome reveals that approximately 24.35% of the study area falls under PFCZ, whereas about 75.65% of the study area falls under the safe zone with respect to potential fluoride contamination. On validation of the PFCZ, the reported fluoride contamination data in groundwater shows an overall 87.50% accuracy in prediction via superimposition method and 89.06 and 85.85% success and prediction rates, respectively, when validated with success and prediction rates. [ABSTRACT FROM AUTHOR]

The hypothesis of the present work is that the groundwater regulations of the Chilean Water Code are insufficient because they look only at quantitative aspects of interest to owners of water rights, but do not serve to protect the quality of the aquifer as a common good. To prove this hypothesis, a legal and technical review of how groundwater catchment protection areas are regulated in Spanish and US law, especially when used for human consumption, was carried out. After this review, we contrasted these regulations with Chilean standards, particularly the Water Code and Supreme Decree 203 of 2013. We concluded that there are at least two substantial differences: a) Chilean legislation does not impose any restrictions on the establishment of polluting activities near the drinking water collection point, emphasizing the quantity of the resource rather than the protection of its quality. The law prevents only the opening of new groundwater collection points near the first. In addition, b) the protection area is not variable; it always remains the same regardless of the intended objective, site characteristics or the speed at which a contaminant advances. [ABSTRACT FROM AUTHOR]

Environmental isotopic study has been conducted in Faridkot and Muktsar districts of Punjab to assess the uranium contamination as well as to determine the isotopic signatures of contaminated groundwater. Results indicate that U levels range from 3 to 190 µg/L and ten samples are contaminated out of twenty collected. Uranium contamination is observed both in shallow and deep groundwaters but decreases with depth. Positive correlation was found between alkalinity and U. The δO values range between −9 and −6‰ and do not show any distinction between contaminated and uncontaminated groundwater. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The continuous and large-scale abstraction of groundwater has created a groundwater depletion problem in several parts of the Punjab state including Bist Doab, the interfluve region of Beas and Satluj rivers. In the present study, a few important parameters, viz. water level, stable isotope, EC, temperature, groundwater age, that can be used to fingerprint the over-exploitation of groundwater have been examined. It has been observed that with the increase in over-exploitation, the yield of shallow aquifer is progressively getting reduced and as a result forcing the farmers to sink their wells to deeper depths. With abstraction of deeper aquifer, the storage of old groundwater at the deeper aquifer is declining and getting replaced by induced accelerated inflow of young water from the recharge zone and the overlying shallow aquifer. The signatures of the modern water have been observed in the data analyzed for isotopic, hydro-chemical facies, electrical conductivity and temperature of water from deeper aquifer. The study has identified the usefulness of these parameters for identifying groundwater over-exploitation in the region. Depleting water resource may stagnate the economic progress of the region. The paper provides suitable water resource management strategies to be adopted to improve the sustainability of water resources and economic growth in the region. [ABSTRACT FROM AUTHOR]

Long-term groundwater recharge from rainfall in the Nile Delta is needed as an input for integrated groundwater modelling in the Nile Delta aquifer for more accurate simulation. The main objective is to estimate the spatial and temporal variation of groundwater recharge from rainfall in the Nile Delta aquifer. Water and Energy Transfer between Soil, Plants and Atmosphere under quasi-Steady State (WetSpass) model parameters were identified for the Nile Delta based on the available meteorological data for the area collected in 1991 and 2000. The collected data were rainfall, temperature, wind speed and evapotranspiration. Geomorphological characteristics, such as soil type, topography, groundwater depth and slope, were also collected as input data for the WetSpass model. ENVI software was used to come up with land use classification based on available land cover images of the Nile Delta for 1972, 1984, 1990, 2000 and 2009. The WetSpass model was calibrated by comparing the simulated groundwater recharge with the calculated one by using the water balance equation model. The results indicated close agreement in groundwater recharge between the two model outputs with R of 0.99 and 0.94, while the root-mean-square errors (RMSEs) were 4.86 and 9.39 mm for 1991 and 2000, respectively. The WetSpass model was then applied in respect of 1970, 1980, 1990 and 2010 for the purpose of validation. The overall RMSE and R for the 6 years were 8.83 mm and 0.88, respectively. The results of the WetSpass calibrated model provide information to support integrated groundwater modelling. The results reveal that WetSpass works well in simulating the components of the hydrological balance in the Nile Delta. [ABSTRACT FROM AUTHOR]

The Ganges River basin faces severe water challenges related to a mismatch between supply and demand. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3-4 months (June-September) of the monsoon season. Yet, the highest demands occur during the 8-9 months (October-May) of the non-monsoon period. Addressing this mismatch, which is likely to increase with increasing demand, requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River basin is problematic. A range of interventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface-subsurface water exchange, has long been known as the GangesWater Machine (GWM). The approach of the GWM for providing such SSS is through additional pumping and depleting of the groundwater resources prior to the onset of the monsoon season and recharging the SSS through monsoon surface runoff. An important condition for creating such SSS is the degree of unmet water demand. The paper shows that the potential unmet water demand ranging from 59 to 124Bm3 year-1 exists under two different irrigation water use scenarios: (i) to increase irrigation in the Rabi (November-March) and hot weather (April- May) seasons in India, and the Aman (July-November) and Boro (December-May) seasons in Bangladesh, to the entire irrigable area, and (ii) to provide irrigation to Rabi and the hot weather season in India and the Aman and Boro seasons in Bangladesh to the entire cropped area. However, the potential for realizing the unmet irrigation demand is high only in 7 sub-basins in the northern and eastern parts, is moderate to low in 11 sub-basins in the middle, and has little or no potential in 4 sub-basins in the western part of the Ganges basin. Overall, a revived GWM plan has the potential to meet 45-84Bm3 year-1 of unmet water demand. [ABSTRACT FROM AUTHOR]

A hydrogeochemical study was carried out to assess the groundwater quality in parts of Kali watershed in Bulandshahr and Aligarh district. 42 groundwater samples each were collected from hand pumps in pre-monsoon and post-monsoon period 2012 respectively and analysed for pH, EC, TDS, Total Hardness, silica, anions (Cl, HCO, CO, SO, F & NO) and cations (Ca, Mg, Na & K). On the basis of various diagrams and plots, groundwater has been assessed for its hydrochemical characteristics and suitability for irrigation and drinking purposes. Results show dominance of alkalis and bicarbonates. The dominant facies identified from piper diagram is Na-K-HCO. Four chemical groups of water have been identified on L-L diagram and majority of the samples fall in alkali-bicarbonate type and mixed type groups. Possible aqueous species in the groundwater are Mg(HCO), Ca(HCO), NaHCO, NaCl, CaSO, KSO and NaSO. The US salinity diagram and Residual Sodium Carbonate (RSC) suggest that the water is suitable for irrigation purpose. Nitrates in groundwater are within permissible limits except in 3 different locations in each season, which show high values due to the contamination from a landfill site and application of fertilizers. High positive correlation was observed between TDS and Na, Cl, Mg and Total Hardness (TH). Sodium show good correlation with Cl. Correlation of silica with Cl and TDS was done to assess the geogenic or anthropogenic involvement in evolving groundwater quality. Anthropogenic contributions from agricultural and domestic sources and weathering of rock forming minerals control the hydrochemistry of the area. [ABSTRACT FROM AUTHOR]

In irrigation districts with shallow water table, groundwater evaporation (ET) and groundwater depth are important variables for the study of water balance. These variables are influenced by natural factors and human activity. In this study, a new method of simulating ET was used for SWAT, and the computing and output modules of groundwater depth were established. In addition, based on simulations, we analyzed the influences of irrigation schedules and soil types on ET and groundwater depth in the Irrigation Districts along the Lower Reach of Yellow River Basin. The applicabilities of the three methods (Hargreaves, Priestley-Taylor and Penman-Monteith) simulating potential evapotranspiration in SWAT 2000 were evaluated by the measured groundwater evaporation, and Hargreaves was applied in the simulation for irrigation district due to its smallest simulation error. The results presented that the mean groundwater depth decreased with the increase of irrigation amount. However, the changes of soil water storage in root zone and groundwater depth might have more complex effects on the variation of the mean groundwater evaporation. Loamy sand had the smallest annual mean groundwater depth and mean annual ET in the study area, while silt loam corresponded to the largest groundwater depth and groundwater evaporation. This study provides a new method for making simulations and analyses of the hydrological cycle in irrigation districts which has a shallow water table. [ABSTRACT FROM AUTHOR]

ABSTRACT: Lahore is a Mega Metropolitan City located in Punjab, Pakistan. With a population of 13 Million people, it is the second largest city in the country. It is located on the alluvial plain of the Indus basin at an altitude ranging between 682 ft to 698 ft above mean sea level. It is bounded by the Ravi River in the Northwest and Banbanwala-Ravi-Bedian-Depalpur (BRBD) Link Canal and its off-takes in the north and east. Ground-water is the only source for domestic, commercial, and industrial use in the city. The unplanned excessive pumpage of ground water is a constant threat to the Lahore aquifer, which is depleting rapidly (Ahmad, 1974; Rosemann, 2005). In 1947 the groundwater depth in Lahore city was 15 to 16 feet which has now depleted to about 150 feet that come to almost 2.50 feet per year. River Ravi has been the major source of freshwater recharging into the Lahore aquifer for millennia, but the hydrological scenario has radically changed over the last few decades (Qureshi and Sayed, 2013; Ahmad et al., 2002; NESPAK et al., 1987). The Indus Water Treaty of 1960 granted the neighboring country India exclusive rights over the three eastern rivers, including the River Ravi, as a result of which the flows into River Ravi started diminishing gradually. After the construction of Thein Dam on river Ravi in India during the year 2000, the flows in the river have drastically reduced, resulting in depleted recharge to the aquifer around the river. The factors responsible for the depletion of the Lahore aquifer have been enumerated and alternate sources to make up and sustain the water supplies to the metropolitan have been proposed. [ABSTRACT FROM AUTHOR]

A Water Footprint Assessment is carried out for Morocco, mapping the water footprint of different activities at river basin and monthly scale, distinguishing between surface- and groundwater. The paper aims to demonstrate the added value of detailed analysis of the human water footprint within a country and thorough assessment of the virtual water flows leaving and entering a country for formulating national water policy. Green, blue and grey water footprint estimates and virtual water flows are mainly derived from a previous grid-based (5×5 arc minute) global study for the period 1996–2005. These estimates are placed in the context of monthly natural runoff and waste assimilation capacity per river basin derived from Moroccan data sources. The study finds that: (i) evaporation from storage reservoirs is the second largest form of blue water consumption in Morocco, after irrigated crop production; (ii) Morocco’s water and land resources are mainly used to produce relatively low-value (in US$/m3 and US$/ha) crops such as cereals, olives and almonds; (iii) most of the virtual water export from Morocco relates to the export of products with a relatively low economic water productivity (in US$/m3); (iv) blue water scarcity on a monthly scale is severe in all river basins and pressure on groundwater resources by abstractions and nitrate pollution is considerable in most basins; (v) the estimated potential water savings by partial relocation of crops to basins where they consume less water and by reducing water footprints of crops down to benchmark levels are significant compared to demand reducing and supply increasing measures considered in Morocco’s national water strategy. [ABSTRACT FROM AUTHOR]

An attempt was made in the present study to delineate how the radon concentrations vary with respect to different geological formations and to evaluate annual effective dose exposure due to ingestion of radon. A total of 60 groundwater samples were collected from layered sequential aquifers in Chitradurga district having major rock types such as Bababudan Group, Charnockite, Chitradurga Group, Closepet granite, migmatites and granodiorite - tonalitic gneisses and Sargur Schist complex during pre-monsoon and post-season of the year 2011. Radon measurement was made using Durridge RAD-7 radon-in-air monitor, connected to RAD HO accessory with closed loop aeration concept. In the present study, the radon activity ranged from 0 to 186.6 Bq/L and 0 to 150.6 Bq/L during pre- and post-monsoon seasons of the year 2011, with 56.67 % (17 samples) of samples during both the seasons exceeding the EPA's MCL value of 11.1 Bq/L. The annual mean radon activity in the groundwater was higher in the area having Chitradurga rock group formations (78.1 Bq/L) followed by Sargur-Satyamangalam schist complex group (56.8 bq/L), migmatites and granodiorite - tonalitic Gneisses group (56.3 Bq/L), Closepet granite (42.7 Bq/L), Charnonkite (29.1 Bq/L) and Bababudan Group (22.2 Bq/L). It is inferred that radon concentration found to depend on the tectonic structure, geology of the area and on the presence of uranium minerals in these rocks. The annual effective dose resulting from radon in groundwater in the Chitradurga district were significantly lower than UNSCEAR and WHO recommended limit of 1 mSv/y. [ABSTRACT FROM AUTHOR]

The state of Punjab-a part of the Indus basin of the Indian subcontinent has an excellent net work of irrigation facilities. However, due to intensive cultivation it is facing a major problem with respect to quality of groundwater for irrigation. In the present investigation, geo-referenced groundwater samples were analysed to map water quality using geographical information system. Electrical conductivity varied from 0.418 to 5.754 dS m with an average of 1.365 dS m. The carbonate ranged between 0 and 120 mg L, whereas bicarbonate ranged from 5 to 1,000 mg L. Chloride varied from 7 to 2,347 mg L. Calcium plus magnesium ranged from 12 to 1,216 mg L with a mean value of 169 mg L. Sodium adsorption ratio ranged between 0.0 and 34.78 with an average of 2.66 meq L. Residual sodium carbonate varied from 0 to 21.30 meq L with a standard deviation of 2.24. The Geographic Information System (GIS)-based mapping indicated that water in suitable category spatially covered 45.7 % of the state which is located mostly in the sub-mountain (Siwalik Hills), north-eastern undulating and piedmont and alluvial plain agro-eco-subregions. Marginally suitable groundwater spatially covered 46.1 % in the central alluvial plain and south-western alluvial plain agro-eco-subregions. Unsuitable groundwater covered 8.2 % of the state, mostly in the erstwhile sodic soils areas in the central alluvial plain and south-western alluvial plain agro-eco-subregions. GIS-based maps are effective in identifying hot spots which need immediate attention and call for strategic planning for sustainable management. [ABSTRACT FROM AUTHOR]

ABSTRACT On the basis of the characteristics of the oasis hydrological recycling processes in the lower reaches of the Tarim River, the impacts of surface water and groundwater on soil salt content were analyzed to determine how these processes affect soil salinization. The results showed that the relationship between surface water quality and soil salt content in the 0-50 cm layer of soil was significantly positive, with soil salt content declining as groundwater depths increased. However, there was no clear correlation between surface water and salt content in the 50-100 cm layer of soil. When the groundwater depth was <6 m, the soil salt content showed a high-surface concentration, exhibiting a 'T' distribution and decreased with increasing soil depth in the order of 0-20 cm > 20-50 cm > 50-100 cm. However, with increasing groundwater depth (>6 m), soil salt loads were reduced and showed a 'rhombus' distribution, mainly accumulating in the middle layer in the order of 20-50 cm > 0-20 cm > 50-100 cm. When groundwater depth was greater than 6 m, the hardness, total dissolved solids (TDS), and conductance of the groundwater underwent a radical change. Thus, the critical threshold groundwater depth for condensing salt content in groundwater and changing soil salt load distributions was deemed to be 6 m. Salt accumulation in the 0-50 cm layer of soil was determined by the TDS volume in the groundwater when groundwater depth was shallow, which accounted for more than 90% of salt accumulation. However, salt accumulation was determined by the volume of TDS in irrigation water when groundwater depth increased. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

To understand the spatial distribution and the possible sources of high ammonium concentration in the unconfined coastal aquifer of the Po River Delta lowland (Italy), a detailed characterization of inorganic nitrogen species was completed. A total of 59 boreholes were drilled to collect core samples and groundwater samples of the aquifer. Among them, four piezometers, located along a representative flow line, were chosen to monitor the inorganic nitrogen concentrations with depth. Ammonium is the prevalent nitrogen inorganic species in groundwater, and its concentration increases with depth and salinity. Very high ammonium concentrations are found in coincidence with peaty sediments in the salinized anoxic aquifer and in the low-lying aquitard. In particular, the elevated ammonium concentration derives from mineralization of organic matter present in fine sediments deposited in paleo-marsh environments. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Central Godavari delta is located along the Bay of Bengal Coast, Andhra Pradesh, India, and is drained by Pikaleru, Kunavaram and Vasalatippa drains. There is no groundwater pumping for agriculture as wells as for domestic purpose due to the brackish nature of the groundwater at shallow depths. The groundwater table depths vary from 0.8 to 3.4 m and in the Ravva Onshore wells, 4.5 to 13.3 m. Electrical Resistivity Tomography (ERT) surveys were carried out at several locations in the delta to delineate the aquifer geometry and to identify saline water aquifer zones. Groundwater samples collected and analyzed for major ions for assessing the saline water intrusion and to identify the salinity origin in the delta region. The results derived from ERT indicated low resistivity values in the area, which can be attributed to the existence of thick marine clays from ground surface to 12-15 m below ground level near the coast and high resistivity values are due to the presence of coarse sand with freshwater away from the coast. The resistivity values similar to saline water <0.01 Ω m is attributed to the mixing of the saline water along surface water drains. In the Ravva Onshore Terminal low resistivity values indicated up coning of saline water and mixing of saline water from Pikaleru drain. The SO/Cland Na/Clratios did not indicate saline water intrusion and the salinity is due to marine palaeosalinity, dilution of marine clays and dissolution of evaporites. [ABSTRACT FROM AUTHOR]

Pakistan’s Indus Basin irrigation system, conceived initially as a vast network of gravity-fed canals, has evolved into a quasi-conjunctive management system in which pumped groundwater increasingly augments surface water supplies. Analysis of the evolution of on-farm energy use for agriculture in Punjab Province over the last 15 years finds that while total crop production increased 31%, direct energy intensity for agriculture increased 80%. Moreover, direct energy use is chiefly driven by groundwater pumping (61%). Important knowledge gaps are identified in the critical water-energy-food interdependencies that need to be addressed for sustainable management of scarce natural resources in Pakistan. [ABSTRACT FROM AUTHOR]

The sustainable development and management of groundwater resource requires precise quantitative assessment based on scientific principle and modern techniques. In the present study, groundwater potential zone are delineated using remote sensing, geographical information system (GIS) and multi-criteria decision making (MCDM) techniques in Unnao district, Uttar Pradesh. The analytical network process (ANP) is a method that makes it possible for one to deal systematically, and includes the analytical hierarchy process (AHP) as a special case. The AHP and ANP are used to determine the weights of various themes and their classes for identifying the groundwater potential zone. These weights are applied in a linear combination to obtain five different groundwater potential zone in the study area, namely 'very poor', 'poor', 'moderate', 'good' and 'very good'. It has been concluded that about 153.39 km area has very good groundwater potential which is only 3.37% of the total study area. However, the area having very poor groundwater potential is about 850 km which is about 19.63% of the study area. The area having good, moderate and poor groundwater potential is about 540.25, 1135.5, 1868.6 km, respectively. The groundwater potential zone map was finally verified using the well yield data of 37 pumping wells, and the result was found satisfactory. [ABSTRACT FROM AUTHOR]

Hierakonpolis, Greek for City of the Hawk, nearly 25 km NW of Idfu (Egypt), is an important and extensive archaeological discovery covering a large area. Its richness in archaeological artifacts makes it a valuable site. It has a valid claim to be the first nation state, as indicated by the Palette of Narmer discovered in its main mound. Geological and hydrogeological investigations at the Hierakonpolis Temple Town site documented nearly a 4.0-m water table rise from as early as 1892 to the present. In addition to the rising water levels, the increase of both subsoil water salinity and humidity threatens and damages fragile carvings and paintings within tombs in Kingdom Hill, the foundation stability of the site, and the known and still to be discovered artifact that recent pottery finds dates at least 4,000 BCE. Representative rock and soil samples obtained from drilled cores in the study area were chosen for conducting detailed grain size and X-ray analysis, light and heavy mineral occurrences, distribution of moisture and total organic matter, and scanning electron microscopy investigations. Mineralogical analysis of clays indicated that the soil samples are composed of smectite/illite mixed layers with varying proportions of smectite to illite. Kaolinite is the second dominant clay constituent, besides occasional chlorite. Swelling of the clay portion of the soil, due to the presence of capillary groundwater, in contact with buried mudbrick walls expands and causes severe damage to important exposed and buried mudbrick structures, including the massive ancient 'fort' believed to date from the Second Dynasty (from 2,890 to 2,686 BC). The 'fort' is 1.0 km south of the Temple Town mounds near to confluence of Wadi Abu Sufian. Groundwater samples from the shallow aquifer close by the intersection of Wadi Abu Sufian and the Nile flood plain were analyzed for chemical composition and stable isotope ratios. The groundwater in the upper zone (subsoil water) within fine-grained Nile alluvium is characterized by high salinity which varies from 415 to 4,500 mg/L total dissolved solids. In contrast, most of the groundwater samples in the lower zone (Quaternary aquifer) are characterized by a low salinity in the order of 164-792 mg/L. Values of δD and δO obtained from this deep (9-20 m) aquifer ranged from 16.98 to 19.87 ‰ and from 1.67 to 2.99 ‰, respectively. These values indicated that the Quaternary aquifer waters are recharged directly from recent Nile water. Subsoil water is very shallow in the area; it ranged from 0 to 2.6 m with a mean of 1.1 m within the main mound of the Hierakonpolis Temple Town site by 2003, in contrast to its more than 4.5-m depth in 1897. The exposure of subsoil water to increased evaporation is expected, with a consequent increase in the concentrations of dissolved solids and usually large proportions of chloride and sulfate. Artifacts recovered from the Temple Town site are becoming damaged and destroyed by crystallization processes caused by repeated wetting and drying of salt and the accumulation of new salts. [ABSTRACT FROM AUTHOR]