Suitability Of Groundwater For Irrigation Research Articles

The Integration of Multivariate Statistical Approaches, Hyperspectral Reflectance, and Data-Driven Modeling for Assessing the Quality and Suitability of Groundwater for Irrigation

Sustainable agriculture in arid regions necessitates that the quality of groundwater be carefully monitored; otherwise, low-quality irrigation water may cause soil degradation and negatively impact crop productivity. This study aimed to evaluate the quality of groundwater samples collected from the wells in the quaternary aquifer, which are located in the Western Desert (WD) and the Central Nile Delta (CND), by integrating a multivariate analysis, proximal remote sensing data, and data-driven modeling (adaptive neuro-fuzzy inference system (ANFIS) and support vector machine regression (SVMR)). Data on the physiochemical parameters were subjected to multivariate analysis to ease the interpretation of groundwater quality. Then, six irrigation water quality indices (IWQIs) were calculated, and the original spectral reflectance (OSR) of groundwater samples were collected in the 302–1148 nm range, with the optimal spectral wavelength intervals corresponding to each of the six IWQIs determined through correlation coefficients (r). Finally, the performance of both the ANFIS and SVMR models for evaluating the IWQIs was investigated based on effective spectral reflectance bands. From the multivariate analysis, it was concluded that the combination of factor analysis and principal component analysis was found to be advantageous to examining and interpreting the behavior of groundwater quality in both regions, as well as predicting the variables that may impact groundwater quality by illuminating the relationship between physiochemical parameters and the factors or components of both analyses. The analysis of the six IWQIs revealed that the majority of groundwater samples from the CND were highly suitable for irrigation purposes, whereas most of the groundwater from the WD can be used with some limitations to avoid salinity and alkalinity issues in the long term. The high r values between the six IWQIs and OSR were located at wavelength intervals of 302–318, 358–900, and 1074–1148 nm, and the peak value of r for these was relatively flat. Finally, the ANFIS and SVMR both obtained satisfactory degrees of model accuracy for evaluating the IWQIs, but the ANFIS model (R2 = 0.74–1.0) was superior to the SVMR (R2 = 0.01–0.88) in both the training and testing series. Finally, the multivariate analysis was able to easily interpret groundwater quality and ground-based remote sensing on the basis of spectral reflectance bands via the ANFIS model, which could be used as a fast and low-cost onsite tool to estimate the IWQIs of groundwater.

Assessment of Groundwater Geochemistry of Vel River basin, Western Maharashtra, India

To study the chemistry of major ion in groundwater from Vel (Velu) River basin, sixty (60) samples of dug wells and bore wells were collected and analyzed using standard techniques given by APHA. It shows order of dominance for cations, Na+ > Ca2+ > Mg2+ > K+ and in anionic concentration as HCO3- > Cl- > SO42- in groundwater. The pH of groundwater is slightly alkaline (range: pH 7.0 - 8.1), while average values of Electrical Conductivity (EC) is about 2641 µS/cm indicating high mineralization of groundwater. In general, the cationic concentration (Na+, K+, Ca2+ and Mg2+) of the groundwater increase in the downstream side (from Northwest to South east), suggesting geological control on the composition of groundwater while highest concentration is in lower part of the basin are generally associated with the high salinity. In the major anions, bicarbonate (HCO3-) is higher due to rock-water interaction. Average value of chloride is about of 235 mg/L due to discharge zones along with anthropogenic activities. The geochemical data plotted on Piper Trilinear Diagram is showing dominant hydro-chemical facies: Ca2++Mg2+, Na++ K+, Cl-+ SO42- -HCO3- found in 83.3 % samples indicating the alkaline earth exceeding the alkalis and the strong acids exceeds the weak acids. The pH, Total Hardness (TH) and Magnesium (Mg2+) of the samples show more proportion of samples falling above desirable limit. Otherwise the quality of groundwater is good for drinking. The irrigation indices like SAR, KR and SSP were considered to evaluate groundwater suitability for irrigation. Comparing with SAR parameter all samples are excellent to good for irrigation. In SSP, 33.3 % samples are within permissible, while 66.6% samples are doubtful for irrigation purpose. In KR almost all samples (excluding 04 samples in lower side of basin) are suitable for irrigation. So, variations in climate, geology with anthropogenic activities are modifying the groundwater geochemistry of Vel River Basin.

HYDROCHEMICAL ASSESSMENT OF GROUNDWATER OF EUPHRATES AQUIFER IN ANAH, WESTERN IRAQ FOR IRRIGATION PURPOSES

Groundwater quality is of prime importance in determining its suitability for various human activity such as irrigation, therefore, groundwater samples are collected from selective wells in Anah city and subjected to hydrochemical analysis in order to measure the concentrations of the major ions, in addition to the Electrical Conductivity, pH, Total Dissolved Solids, Soluble Sodium Percentage (Na%), and Sodium Adsorption Ratio)SAR( to assess the suitability of groundwater for irrigation. Results showed that the groundwater in Anah city is characterized by excellent to good SAR with good Na% and accepted value of pH for irrigation, whereas, values of Electrical Conductivity and Total Dissolved Solids were not acceptable due to the rising of salinity (SO4 and Cl). According to Piper diagram, the type of water is Earth alkaline.

Hydrogeochemical Assessment of Groundwater for Drinking and Agricultural Use: A Case Study of Rural Areas of Alwar, Rajasthan.

Groundwater contributes substantially to the development of arid and semi-arid regions around the globe. The present study integrates groundwater quality and its suitability for drinking and irrigation around Alwar city of Rajasthan state, where agriculture is the major land use. The application for drinking was assessed by comparing the observed value with prescribed standards of WHO. Groundwater was found suitable for drinking at most of the locations. The suitability of groundwater for irrigation was determined by calculating ion-based ratios and comparing them against the suggested ratios and indices for agricultural quality. Suitability for irrigation was assessed against electrical conductivity (EC), percentage sodium (%Na), residual Na2CO3 (RSC), per cent soluble sodium (SSP), sodium adsorption ratio (SAR), Mg hazard and permeability index (PI) etc., and the quality was compromised for EC, %Na and Mg Hz. Since the soil was sandy, the groundwater was found suitable for irrigation over long-term use, with the only problem of magnesium hazard. Based on the different ratios of anions and cations, silicate weathering was observed to be regulating groundwater chemistry, and the groundwater belonged to mixed CaMgCl and CaHCO3- type based on Piper's classification and relative abundance of ions. Further, meteoric genesis classification showed that the groundwater in the study region had direct base exchange and shallow meteoric water percolation. Presence of kaolinite and quartz minerals in soil confirmed that silicate weathering is the major process controlling groundwater chemistry.

Evaluation of groundwater quality in intensive irrigated zone of Northeastern Tunisia

Accurate and reliable prediction of groundwater quality is a critical component in water resources management and sustainable utilization. The multilayered Nadhour-Saouaf aquifer system in Northeastern Tunisia is intensively exploited. It is the main source of freshwater for domestic, agricultural, and industrial needs. The current study aims to identify groundwater and surface waters geochemistry and its suitability for irrigation and drinking purposes. A total of 31 groundwater samples and three surface water samples were collected and analyzed for the major elements, nitrates and physicochemical parameters. Hydrochemical facies are of mixed Ca–Mg–Cl and Na–Cl types for water of the Oligocene reservoir level and of a mixed Ca–Mg–Cl facies type for the Miocene and Plio-Quaternary waters. The water suitability for drinking purpose was evaluated based on World Health Organization, Tunisian standards guidelines and Drinking Water Quality Index (DWQI). The evaluation showed considerable deterioration in groundwater quality at some location. A large proportion (68%) of samples is unsuitable for drinking purpose based on WHO guidelines. The waters sampled from the dams are not directly useful for drinking and need specific treatment. However, DWQI results show that “Good water’’ class dominates in the study area. The suitability of groundwater for irrigation was evaluated based on the irrigation quality parameters such as sodium absorption ratio, sodium proportion, Permeability Index, Kelly's ratio, Magnesium hazard and Irrigation Water Quality Index (IWQI). Groundwater samples classified, based on previously parameters, reveal that 42% are unsafe for irrigation. Subsequently, multiple linear regression is used for DWQI and IWQI simulation. The model results showed a great correspondence between distribution maps of estimated and measured DWQI and IWQI. Hence, the developed models provide a simpler and easy alternative to other methods used for suitability estimation and prediction.

Coupled multivariate statistical analysis and WQI approaches for groundwater quality assessment in Wadi El-Assiuty downstream area, Eastern Desert, Egypt

Groundwater is the primary source of fresh water for agriculture and other purposes in the Wadi El-Assiuty area; therefore, the preservation of its supply and quality is of great importance. The present study aims to evaluate the groundwater quality in the newly reclaimed parts of Wadi El-Assiuty by integrating hydrochemical data, multivariate statistical analyses, and a water quality index (WQI). In this study, 48 groundwater samples were collected and analyzed for 12 physicochemical parameters. Multivariate statistical approaches, including a correlation matrix, factor analysis, and hierarchical cluster analysis, were applied to differentiate the source of the water quality variation and determine the cause of groundwater deterioration. The factor analysis identified three main factors describing the groundwater quality in the study area, and the cluster analysis indicated two main distinct clusters of the analyzed variables. The spatial variation maps of the analyzed parameters were developed using interpolation techniques within a geographic information system environment. The WQI was applied according to the chemical drinking-water quality standards of the World Health Organization (WHO) with respect to the 12 parameters measured to evaluate the suitability of the groundwater for human consumption. The resultant WQI showed that approximately 54% of the collected groundwater samples were of an acceptable quality for human consumption with respect to the 12 parameters measured. The suitability of groundwater for irrigation was evaluated according to the salinity hazard (as electrical conductivity, EC), sodium adsorption ratio (SAR), sodium percentage (Na%), and magnesium hazard (MH). From the results, 40% of the collected samples were “permissible” for irrigation with respect to the EC, 82% were “good” to “excellent” with respect to the SAR values, 29% were “permissible” with respect to the Na%, and 90% were “suitable” with respect to the MH.

Evaluation of water quality for agricultural suitability in the Benslimane region, Morocco.

Morocco is basically a semiarid country with limited rainfall reducing the opportunities for rainfed agriculture. For feeding its ever growing population, irrigation is required. This study aims to evaluate the groundwater quality for irrigation in the Benslimane region by studying the main influencing chemical elements and characteristics. The main purpose is to provide the farmers and agricultural developers with a clear comprehension of the groundwater status. We focused on the determination and statistical analysis of physicochemical parameters and major elements (electrical conductivity, pH, Na+, K+,Ca2+, Mg2+, Cl-, SO42-, CO32-, and HCO3-) for 120 samples and the derivation of water quality indices like SAR, %Na, RSC, PI, KR, and MAR, along with graphical approaches such as Wilcox's and Richards's diagrams. Factors affecting groundwater hydrochemistry and quality were also discussed. The results show generally alkaline and shallow waters, with the majority of the samples belonging to the Na-Cl facies. Rock alteration, dissolution, ion exchange, evaporation, and anthropogenic activity are the main factors controlling water chemistry. Most prospected wells indicate high salinity problems due to salt water intrusion. With regard to the suitability of groundwater for irrigation, the majority of wells is of medium to poor quality and is therefore unsuitable. These types of water are found throughout the area, with a significant dominance on the coastal zone. The long-term use of this groundwater would therefore have negative impacts on soil quality and the sustainability of agricultural production. Therefore, we recommend proper agricultural management and irrigation practices in the Benslimane region, in order to increase agricultural production while preserving water and soil resources.

Combining Hydrogeochemical Characterization and a Hyperspectral Reflectance Tool for Assessing Quality and Suitability of Two Groundwater Resources for Irrigation in Egypt

Hyperspectral reflectance sensing provides a rapid and cost-effective technique for assessing the suitability of groundwater for irrigation by monitoring real-time changes in its quality at a large scale. In this study, we assessed the quality of 15 groundwater samples from El Fayoum depression in the Western Desert (WD) and 25 groundwater samples from the Central Nile Delta (CND) in Egypt using a traditional approach of the physiochemical parameters, irrigation water quality indicators (IWQIs), and hydrochemical facies. The spectral reflectance data of the water surface was used to build new simple reflectance indices (SRIs), and the performance of these indices for assessing IWQIs was compared with those by partial least square regression (PLSR) that was based on all SRIs or the full-spectrum ranges. Generally, the groundwater of the CND was fresher and more suitable for irrigation purposes than those of the WD. Based on the six IWQIs, ~6.7–60.0% and 85.0–100.0% of the groundwater samples of the WD and CND, respectively, were categorized as highly suitable for irrigation purposes. Based on hydrochemical facies, Na-Cl and Ca-HCO3 were dominant in the WD and CND, respectively, as well as the alkali earth metals (Na+ + K+), which significantly exceeded the alkaline earth metals (Ca2+ + Mg2+) in the WD, with the reverse for the CND. Most developed SRIs had a moderate, weak, and moderate to strong relationship with physiochemical parameters and IWQIs in the WD, CND, and across both regions, respectively. The PLSR models based on all SRIs provided a more accurate estimation of IWQIs in calibration and validation datasets than those based on full-spectrum ranges, and both PLSR models provided better estimation than the individual SRIs. These findings support the feasibility of using ground reflectance measurements as a fast and low-cost tool for the assessment and management of groundwater for irrigation in arid and semiarid regions.

Assessment of groundwater quality based on GIS and geochemical methods: coastal aquifer of Bouficha (North-Eastern Tunisia)

In Tunisia, Groundwater is an important water source for domestic, agricultural and industrial uses, but the deterioration of its quality, under the influence of anthropogenic activities and natural factors, limits its suitability for human consumption and irrigation. The present study was carried out to assess groundwater quality in Bouficha aquifer in north-eastern Tunisia using geochemical, geospatial and statistical techniques. The relationship between groundwater quality and Land Use Land Cover (LULC) patterns were also explored using remote sensing, geographic information system (GIS) and Landsat satellite images. Groundwater samples were collected from sixteen wells in April 2015 and analyzed for their physical and chemical characteristics. Concentrations of major cations and anions in the groundwater vary spatially. The dominant water types in the investigation area are Na-Cl and Ca–SO4. A basic statistical study, applying hierarchical classification analysis confirms the existence of two groundwater types. To evaluate the suitability of groundwater for irrigation, chemical data were assessed using methods such as Electrical Conductivity, Kelley’s ratio, Sodium Absorption Ratio, Magnesium Hazards, as well as Residual Sodium Carbonate. Regarding drinking groundwater assessment, the World Health Organization (WHO) standards were applied to define sites with drinking water permissible levels. Information was loaded in an ArcGIS software and analyzed with a Spatial Analyst extension using Inverse Spline interpolation methods. Fluoride content in most samples has values as high as 1.97 mg/L, with 53% of the samples showing fluoride concentration higher than the level suggested by the WHO for drinking water of 1.5 mg/L and ratified by the National Society of Exploitation and Drinking Potable Water of Tunisia. Additionally, reported nitrate concentrations are higher than the expected groundwater background level of 10 mg/L; indeed, values are up to 286 mg/L, being hazardous for domestic use and suggesting the presence of anthropogenic sources of water contamination. The Land Use and Land Cover (LULCC) of Bouficha aquifer were changed over seventeen years. The Landsat satellite images have shown that the built-up area increased from 2001 to 2018 to the detriment of water and crop vegetation. The overuse of fertilizers on a total agricultural area of Bouficha aquifer (60%) led to significant pollutants, including nitrate and a deterioration in its water quality. Regarding the WHO and the Tunisian drinking water guidelines, this work provides substantial evidence that groundwater quality is posing a significant health threat for residents. Similarly, results show groundwater’s chemical content is also unsuitable for economic activities in the Bouficha region, mainly hazardous for irrigation purposes.

Evaluation of hydrochemical properties and groundwater suitability for irrigation uses in southwestern zones of Jashore, Bangladesh

The evaluation of hydrogeochemistry and groundwater quality for irrigation purposes has become a major concern for the inhabitants of southern part of Bangladesh. In this present study, the suitability of irrigation system has been shown by the spatial distribution maps using irrigation water quality index (IWQI). One hundred groundwater samples were collected to evaluate groundwater quality for irrigation system using IWQI, and atomic absorption spectrophotometer, ultraviolet spectrophotometer and titration methods were used for identification of groundwater quality using various parameters. ArcMap 10.5 (GIS), geospatial analysis tools (SSPS), descriptive statistics, correlation matrix and interruption methods were applied owe to produce the maps of geospatial distribution, and measurement of suitable area for irrigation. The hydrochemical parameters of pH, EC, TDS, Na, K, Ca, hardness, Mg, NO3N, Cl, Fe, HCO3, SO4 and NO3 were analyzed for the field investigation, and the IWQI was evaluated by indexes of KI, Na (%), PI, SAR, and SSP from the field investigation parameters. The result of total investigation model reveals on the irrigation system that 925.38 km2 area is highly suitable, 462.69 km2 area is good, 385.57 km2 area is permissible limit or moderately good, 359.87 km2 area is poor lower restrictions and 436.98 km2 areas is highly restrictions or very poor because of salinity (sodium-chloride). Therefore, immediate remediation is required in high risk or restriction of the salinity for the irrigation systems.

Assessment of the groundwater suitability for irrigation near Al Kufa City and preparing the final water quality maps using spatial distribution tools

In many parts of the world, groundwater quality is decreasing due to urbanization industrialization and use of agricultures in rural areas. This subject has formed an urgent need to determine the suitability of groundwater for various purposes. The aim of this study is to determine a groundwater index for groundwater use for irrigation in agriculture. The study is carried out in an agricultural area; near Al Kufa city, North of Al Najaf province, Iraq. Many chemical variables are used in this model, including (total dissolved solids TDS, electrical conductivity EC, sodium Na, potassium K and iron Fe), in addition to some of the heavy metals (cadmium Cd, lead Pb, chromium Cr, and nickel Ni), that also added to the index. The weight’s parameters are determined using analytical hierarchy process (AHP) and classified into five groups based on the human health significance of these parameters and negative effect on agriculture. The result of this study indicates that the water quality index (WQI) records values between (0 and 4.33), and in which the value of (2.16) represents the limit between unpolluted and polluted groundwater. This study confirms that all groundwater samples over the study area are suitable for agriculture. The final WQI values are exported to ArcMap environment to prepare the final WQI maps of study area.

Seasonal variability of groundwater quality in coastal aquifers of Kavaratti Island, Lakshadweep Archipelago, India

Lakshadweep Archipelago is comprised of several tiny coral atolls and scattered in the Arabian Sea off the south-west of India. Ground water is the only available fresh water resource for the islanders. The groundwater quality is decreased in this island due to population growth and anthropogenic activities like sewage dumping and agricultural activities. For this study, a total of 20 groundwater samples was collected randomly from the open wells that cover the entire area of the island. The physico-chemical parameters of groundwater were analysed in pre- and post-monsoon seasons during the year 2016–2017. The concentration of a majority of the chemical constituents exceeds the standards of WHO during post-monsoon than pre-monsoon season. EC content exhibited the violation of drinking water quality standards. The highest value of EC range 1023–6874 μS/cm recorded in post-monsoon than pre-monsoon. TDS concentration range from 574.6 to 1503.4 mg/l and 665–4468 mg/l in pre and post-monsoon seasons. Geochemical evolution diagram categories the groundwater facies into Na+-K+-Cl--SO42-, Ca2+-Mg2+-HCO3-, and Ca2+-Mg2+-Cl--SO42- in both seasons. Gibbs plot revealed that the evaporation is the dominant factor controlling the mechanism of ground water hydrochemistry. The water quality index suggested that both pre-monsoon and post-monsoon around 93.95% of the samples are unsuitable for drinking purposes. The suitability of groundwater for irrigation was studied by calculating the percent of sodium, sodium adsorption ratio, magnesium hazard and Reveille's index. The Wilcox and USSL plots also indicated that most of the groundwater samples are found to be unsuitable for irrigation. HFE diagram productively delineates that groundwater of the study area has strong influence of sea water in the fresh water aquifers. The highest level of significant correlation was observed between Mg-TH (r = 0.87), EC-TDS (r = 0.86), and Cl–Na (r = 0.77) respectively. As a whole, it is observed that the groundwater is not suitable for drinking, irrigation and industrial purposes due to the exceeding of chemical parameters from their standard limits. Therefore, groundwater management measures may be worked out regionally to improve water quality by artificial recharge, rain water harvesting, periodic disinfection of the wells and saving the fresh water stocks in the island accordingly.

Source rock weathering and groundwater suitability for irrigation in Purna alluvial basin, Maharashtra, central India

Purna alluvial basin is characterized by low to high level groundwater salinity having adverse effect in a large area, however, the basin still lacks one-time data of any season regarding hydrogeochemistry and quality assessment for drinking and irrigation purposes. The present work is aimed to determine various weathering indices and estimation of groundwater quality for irrigation purpose. The interpretations are based on the study of total 158 samples, collected from dug wells (60) and bore wells (98) during both pre- and post-monsoon periods of the year 2009. The plots between Ca+Mg vs. SO4+HCO3, Na vs. Cl and Na vs. HCO3 reveal that most of the samples fall below the equiline that indicates prevalence of silicate weathering. The USSL diagram (Wilcox diagram) demonstrates higher concentration of points in the fields of C2S1 and C3S1 for both the aquifers, indicating high salinity and low to medium sodium water; however, a few sample points positioned in C3S4 and C4S4 fields indicate high salinity but medium to high sodium. The values of Na%, RSC, Kelley ratio and magnesium ratio for most of samples exhibit doubtful to unsuitable categories of groundwater for irrigation from both the aquifers during pre- and post-monsoon periods. The vast data bank generated for entire basin is significant for government and non-government organizations for future planning and management.

Temporal Variation of Tropical Karst Groundwater Suitability for Irrigation in Gremeng Resurgence, Gunungsewu Karst Area, Indonesia

Analysis of groundwater availability for irrigation purposes pertains to not only quantity but also quality. The characteristics of groundwater quality essentially define crop productivity and determine whether or not crops can grow. This research was designed to identify the suitability of karst groundwater for irrigation temporally (in one year), with an example of Gremeng Resurgence in Gunungsewu Karst Region, Indonesia. It drew on data on electrical conductivity and several major ions, such as potassium, magnesium, sodium, and calcium, by analyzing % sodium content (Na%), Sodium Adsorption Ratio (SAR), and groundwater suitability for irrigation using the Wilcox and USSL diagrams. These analyses revealed that the water quality observed varied by seasons owing to the effects of dilution by rain and water-rock interaction in the karst region. However, this temporal variation was not substantial so that the classes of groundwater suitability only ranged between good and excellent, and the salinity hazard levels differentiated into low until medium.

Suitability of groundwater for irrigation in Manmunai West Divisional secretariat area of Batticaloa District

The official journal of Agricultural Sciences published by the Faculty of Agriculture, Eastern University, Chenkalady, Sri Lanka.AGRIEAST publishes research information of broad practical significance pertaining to both tropical and subtropical Agriculture.

Integrated assessment of groundwater resources in a semi-arid watershed of South India: implications for irrigated agriculture

Groundwater resources play a vital role in the socio-economic development of Andipatti watershed—a semi-arid region situated in Theni district of Tamil Nadu, South India. Due to a short spell of rainfall (40 days in a year) and ephemeral nature of streams, the quantum of surface water in the watershed is not found to cope with the agricultural requirements and as a result, more emphasis is given to the exploitation of groundwater. The haphazard utilization of groundwater for agricultural practices affects the quantum and quality of groundwater severely. The present study is attempted to assess the potential, level, quality, suitability and utilization level of groundwater resources in an integrated manner. Groundwater potential of the study area is assessed using resistivity, well yield and dug well data. The groundwater potential zones exhibit a strong relationship with land use pattern i.e. poor potential zones is marked by fallow lands. The spatial pattern of groundwater level and quality is examined using the data collected from 34 open wells across the study area during pre-monsoon and post-monsoon seasons. The groundwater level of the watershed varies from 0.5 to 47 m with an average fluctuation of 2 to 4 m. The long-term fluctuations of the groundwater level showed that there is a cyclic trend depending upon the rainfall pattern of the watershed. However, the declining trend of groundwater level noticed especially in the upper part of the watershed. The suitability of groundwater for irrigated agriculture is examined using the concentrations and indices of chloride, magnesium ratio, sodium adsorption ratio, residual sodium carbonate, soluble sodium percentage, and permeability index of the collected groundwater samples. A method formulated by the US Salinity Laboratory is also attempted for the classification of groundwater quality zones. In order to ascertain and suggest sustainable planning measures, utilisation pattern of groundwater is assessed on a micro-watershed scale. The spatial distribution of analyzed parameters shows the suitability of groundwater for irrigation and associated impacts in the watershed.

Classification of Groundwater Suitability for Irrigation in the Ulagalla Tank Cascade Landscape by GIS and the Analytic Hierarchy Process

The tank cascade system (TCS) has been used for over 2000 years for water management in Sri Lanka. Since surface water is limited in the dry zone of Sri Lanka, agricultural production, especially of upland crops, relies on groundwater for irrigation. We sampled 29 wells in the Ulagalla cascade, a prominent TCS near Anuradhapura city in the dry zone of Sri Lanka, in Yala (dry) and Maha (wet) seasons, the two main cropping seasons in Sri Lanka. We evaluated the suitability of groundwater for irrigation using the analytic hierarchy process and geographical information system. Water quality did not vary notably between seasons. However, it deteriorated with the onset of high intensity heavy rain, especially during the Maha season. A water quality zoning map indicated that groundwater in 4% and 96% of the study area is suitable and moderately suitable for irrigation, respectively. Irrigation water quality in tank cascade landscapes and similar environments can be assessed using this methodology and our results.

Hydrochemistry of Groundwater and its Suitability for Drinking and Irrigation in Baghdad, Iraq

The present paper aimed at assessing the hydrochemistry and the water quality of the groundwater in the urban area of Baghdad. Sixty-six groundwater samples were collected from shallow tube wells and analyzed for pH, total dissolved solids (TDS), electrical conductivity (EC), calcium, magnesium, sodium, potassium, chloride, bicarbonate, carbonate, sulfate and nitrate. Groundwater suitability for drinking was evaluated based on the World Health Organization (WHO) and Iraqi standards, whereas suitability of groundwater for irrigation was evaluated based on various hydrochemical parameters and methods, such as sodium adsorption ratio (SAR), residual sodium carbonate (RSC), sodium percentage (%Na), United States salinity diagram, Wilcox’s diagram and magnesium hazards (MH). Results showed that the urban area of Baghdad is highly affected by the anthropogenic sources. Based on Piper diagram, the groundwater in the study area are classified into two water types (NaCl and CaCl), indicating high-salinity water. Gibbs ratio indicates that the majority of the groundwater in the study area is affected by the evaporation process. Furthermore, the ion exchange process revealed that 85% of the groundwater samples indicate chloro-alkaline disequilibrium. Moreover, it was found that all the groundwater samples are unsuitable for both drinking and irrigation purposes.

Assessing groundwater suitability for irrigation: a case study for Durgapur upazila, Netrokona, Bangladesh

Assessing groundwater suitability for irrigation: a case study for Durgapur upazila, Netrokona, Bangladesh

Hydrochemical characterization and geospatial analysis of groundwater quality in Cap Bon region, northeastern Tunisia

The hydrogeochemical characteristics of shallow groundwater in the Grombalia region, northeastern Tunisia, were investigated to evaluate suitability for irrigation and other uses and to determine the main processes that control its chemical composition. A total of 21 groundwater samples were collected from existing wells in January–February 2015 and were analyzed for the major cations and anions concentrations. Conductivity, pH, T°, O2 and salinity were also measured. Interrelationships between chemical parameters were determined by using the scatter matrix method. The suitability of groundwater for irrigation and other uses was assessed by determining the sodium adsorption ratio, soluble-sodium percentage, total dissolved solids, total hardness, Kelly’s index and permeability index values of water samples. The spatial distribution of key parameters was assessed using a GIS-based spatial gridding technique. This analysis indicated that the chemical composition of groundwater in the study area is of Cl–SO4–Na–Ca mixed facies with concentrations of many chemical constituents exceeding known guideline values for irrigation. The salinity of groundwater is controlled by most dominant cation and anion (Na–Cl). A correlation analysis shows that Na+ is the dominant cation and that reverse ion exchange is a dominant process that controls the hydrogeochemical evolution of groundwater in the area. Geospatial mapping of hydrochemical parameters and indices analyzed with the USSL and Wilcox diagrams show distinctive areas of irrigation suitability. In contrast, 76.2% of samples fall in the highly doubtful to unsuitable category and indicate that the central and north-eastern parts of the study area are unsuitable for irrigation due to a high salinity and alkalinity.