Decadal Trends and Spatial Analysis of Irrigation Suitability Indices Based on Groundwater Quality (2015–2024) in Agricultural Regions of Korea

Mountain streams/springs are the primary irrigation water resource in Bhutan Himalaya, besides supporting drinking and other domestic needs. Successful crop production implies an adequate supply of high-quality irrigation water, among other factors. Thus, this study was conducted to assess the suitability of spring-fed streamwater for irrigation use and evaluate hydrogeochemical processes that regulate streamwater chemistry at the Manthong village in Kanglung, Bhutan. The water samples were analyzed for temperature, pH, electrical conductivity (EC), turbidity, total dissolved solute (TDS) and major ions. Piper and Durov diagrams indicated that most samples are of the intermediate type and simple dissolution or linear mixing is the primary hydrochemical process regulating streamwater chemistry. All the measured physicochemical parameters were within the acceptable thresholds of the FAO guidelines recommended for agricultural use. Analytical results of the streamwater water quality indices, including EC, %Na, residual sodium bicarbonate (RSBC), sodium adsorption ratio (SAR), Kelley's ratio (KR) and permeability index (PI), revealed its suitability for irrigation use except for magnesium hazard (MH). The Irrigation Water Quality Index (IWQI) results confirmed that the WS-1 has no restriction as irrigation water; however, WS-2 falls under the high-restriction category. The findings of this study will serve as the baseline data and guide irrigation water management and sustainable irrigation development in the region.

This research assessed the combined influence of permitted landfills and unlicensed dumps coupled with saltwater intrusion on the suitability of groundwater in Rabigh, Saudi Arabia for irrigation purposes. Fourteen water samples were analyzed for physiochemical parameters, major ions, and heavy metals. Quality assessment of groundwater for irrigation purposes was conducted on basis of sodium percentage (Na %), sodium adsorption ratio (SAR), magnesium hazard (MH), permeability index (PI), total hardness (TH), Kelley’s ratio (KR), and soluble sodium percentage (SSP), Wilcox and the Food and Agriculture Organization of the United Nations (FAO) standard limits. Results showed that the domination of ions is in the order Na>Ca>Mg>K and Cl>SO4>HCO3 for cations and anions, respectively. Elevated concentration of Na and Cl coupled with very strong relationships between Na and Cl (r = 0.994), Na and EC (r = 0.995), and between Cl and EC (r = 0.999) indicates a strong influence of Red Sea saltwater intrusion. According to Wilcox and the FAO classifications of salinity (Electrical conductivity (EC)) in irrigation water, it can be concluded that the groundwater in the investigated area of Rabigh is undesirable for irrigation purposes. Based on the Freeze and Cherry classification of total dissolved solids (TDS), the groundwater samples fall in the brackish to saline categories. However, saline water was recognized in the majority of the samples (64%). Concerning the FAO classification, 86% of the samples can be classified in the severe restriction category. According to the categorization of irrigation water based on sodium percentage, two-thirds of the water samples can be classified in the doubtful to unsuitable categories. The very high electrical conductivity values obtained in the groundwater samples near the landfill sites are an indication of the combined effect of leachate and Red Sea saltwater intrusion. The severe restriction is associated with 65% of groundwater samples according to the FAO classification of SAR. Nearly two-thirds of the groundwater samples fall in the medium to high sodium hazard categories. According to Kelley’s ratio and soluble sodium percent, the majority of the groundwater samples (86%) show that the groundwater is undesirable for irrigation purposes. The analytical results of SSP conclude that the majority of groundwater samples (86%) are undesirable for irrigated agriculture. Samples of some groundwater wells show that the concentration of some heavy metals such as Aluminum (Al), Cobalt (Co), Copper (Cu), Chromium (Cr), Nickel (Ni), Vanadium (V), and Zinc (Zn), are higher than the corresponding FAO permissible limits.

Groundwater is an essential resource for drinking and agricultural purposes in the Al-Jouf region, Saudi Arabia. The main objective of this study is to assess groundwater quality for drinking and irrigation purposes in the Al-Jouf region. Physicochemical characteristics of groundwater were determined, including total dissolved solids (TDS), pH, electric conductivity (EC), hardness, and various anions and cations. The groundwater quality index (WQI) was calculated to determine the suitability of groundwater for drinking purposes. The EC, sodium percentage (Na+ %), magnesium hazard (MH), sodium adsorption ratio (SAR), potential salinity (PS), and Kelley’s ratio (KR) were assessed to evaluate the suitability of groundwater for irrigation. Effective statistical tests and Feed-forward neural network (FFNN) modeling were applied to reveal the correlation between parameters and predict WQI. The results indicated that approximately all samples are appropriate for drinking and irrigation uses except samples of the Al Qaryat region. The ionic abundance ranking was Na+ > Ca2+ > Mg2+ > K+ for cations, and Cl− > SO42− > NO3− for anions. Moreover, the groundwater is dominated by alkali metals (K+ and Na+) and controlled by the rock–water interaction process. The indicators of groundwater quality for irrigation and drinking according to the following criteria (Na+ %, SAR, KR, MH, PS, WQI (WHO), and WQI (BIS)) can be predicted by the FFNN with root mean square errors (RMSE) of 0.136, 0.070, 0.022, 0.073, 2.45 × 10−3, 1.45 × 10−2, and 1.18 × 10−2, respectively, and R2 of 0.99, 1.00, 0.99, 0.99, 1.00, 1.00, and 1.00, respectively.

The lack of quality water resources for irrigation is one of the main threats for sustainable farming. This pioneering study focused on finding the best area for farming by looking at irrigation water quality and analyzing its location using a fuzzy logic model on a Geographic Information System platform. In the tribal-prone areas of Khagrachhari Sadar Upazila, Bangladesh, 28 surface water and 39 groundwater samples were taken from shallow tube wells, rivers, canals, ponds, lakes, and waterfalls. The samples were then analyzed for irrigation water quality parameters like electrical conductivity (EC), total dissolved solids (TDS), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium bicarbonate (RSBC), magnesium hazard ratio (MHR), Kelley's ratio (KR), and permeability index (PI). Fuzzy Irrigation Water Quality Index (FIWQI) was employed to determine the irrigation suitability of water resources. Spatial maps for parameters like EC, KR, MH, Na%, PI, SAR, and RSBC were developed using fuzzy membership values for groundwater and surface water. The FIWQI results indicate that 100% of the groundwater and 75% of the surface water samples range in the categories of excellent to good for irrigation uses. A new irrigation suitability map constructed by overlaying all parameters showed that surface water (75%) and some groundwater (100%) in the northern and southwestern portions are fit for agriculture. The western and central parts are unfit for irrigation due to higher bicarbonate and magnesium contents. The Piper and Gibbs diagram also indicated that the water in the study area is magnesium-bicarbonate type and the primary mechanism of water chemistry is controlled by the weathering of rocks, respectively. This research pinpoints the irrigation spatial pattern for regional water resource practices, identifies novel suitable areas, and improves sustainable agricultural uses in tribal-prone areas.

The hydrochemical study of groundwater in Karur district of the Amaravathi River basin has been carried out to assess the major ion chemistry and groundwater quality for domestic and drinking purposes. Twenty-four groundwater samples were collected, processed, and analyzed for various physico-chemical parameters such as pH; electrical conductivity; total dissolved solids; total hardness; cations such as calcium, magnesium, sodium, and potassium; anions such as bicarbonate, chloride, sulfate, fluoride, nitrate, and phosphate in the laboratory using the standard methods given by the American Public Health Association (Standard methods for the examination of water and wastewater, 21st edn. American Public Health Association, Washington DC, 2005). For quality assessment, the results were compared with water quality standards prescribed by the Bureau of Indian standards (Indian standards specification for drinking water 15:10500. Bureau of Indian Standards, New Delhi, 2003) and World Health Organization (International standards for drinking water. World Health Organization, Geneva, 2005). All the groundwater samples in all three seasons (pre-monsoon, monsoon, and post-monsoon seasons) were not useful for drinking purposes owing to elevated levels of Ca2+, Mg2+, Na+, HCO3 −, and Cl−. Karl Pearson correlation matrices for 14 variables were performed; EC, TDS, and TH had significant positive correlations among themselves and also with Ca2+, Mg2+, Na+, and Cl−. pH shows negative correlation with most of the parameters. The piper trilinear diagram showed that groundwater in all three seasons falls into mixed Ca2+–Mg2+–Cl− type. Concerning water for irrigation purposes, parameters such as percent sodium (% Na), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), chloro-alkaline indices (CAI I and CAI II), permeability index (PI), magnesium hazard (MH), Kelley’s ratio (KR), USSL diagram, Gibbs’ ratio (GR), and Wilcox diagram were calculated on the basis of chemical data to evaluate the current status of groundwater in the Amaravathi River basin. Parameters like MH (74 %), KR (75 %), RSC (95 %), and PI (69 %) in all three seasons indicate that the samples are suitable for irrigation and remaining are unsuitable. From USSL diagram, the result reveals that the samples fall in C3-S1 and C4-S1 indicate high to very high-salinity and low-sodium hazards. Wilcox diagram revealed out of 24 samples, sample no. 7, 8, and 11 in pre-monsoon, monsoon, and post-monsoon seasons fall under doubtful to unsuitable and 9 fall under unsuitable zone. The positive CAI values in 66 % samples in all three seasons indicate reverse ion exchange mechanism. The present study may be helpful for further studies concerning water quality issues in this area, where groundwater is a vital for drinking and other activities.

Groundwater resources within river basins are gaining global attention due to their critical role in sustaining human and agricultural needs. Preserving groundwater quality is essential for agricultural productivity and public health, as it serves as the primary source of drinking and irrigation water for billions of people worldwide. This study focuses on the hydrochemical characterisation and quality evaluation of groundwater in the lower urbanized regions of the Kallada River Basin (LKRB), covering Kollam town and its surrounding areas. This study aimed to assess water quality for drinking and irrigation purposes while also evaluating the underlying hydrogeochemical processes. The major cations and anions in groundwater follow the order: Ca2+ > Na+ > Mg2+ > K+ and HCO - > Cl- > SO 2-. The dominant groundwater type is Ca-HCO , followed by Na-Cl. The Water Quality Index (WQI) was employed to evaluate groundwater suitability for drinking. WQI analysis revealed that 80% of samples fell within the 'good to excellent' range, indicating suitability for drinking and domestic use, while 20% were classified as poor quality. Several indices, such as the Magnesium Hazard (MH), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Sodium Percentage (Na%), and Kelley's Ratio (KR), were used to assess the suitability of groundwater for irrigation. The findings indicate that although most samples are safe for irrigation, a few areas have problems with their water quality that render them harmful. This study helps with the sustainable management of groundwater resources in the LKRB by providing important insights for policymakers and urban planners. Keywords: Groundwater Chemistry, Hydro-chemical Facies, Drinking Suitability, Irrigation Suitability, Water Quality Index, Lower Kallada River

The hydrochemical characterization and irrigation suitability assessment of the Ganges-Brahmaputra River System (GBRS) has immense importance for the livelihoods of people and ecosystem sustainability in the region. This study aims to assess the hydrochemical characteristics and evaluate the irrigation suitability of water in the GBRS by reviewing published literature of the major tributaries. The studied rivers were categorized into two groups namely Group-1 and Group-2 considering the similarities of climatic patterns, hydrochemical attributes, and drainage characteristics. The hydrochemistry of the river water was characterized by the Piper diagram, Gibbs plot, mixing plots, and ionic ratios. Furthermore, irrigation water qualities were evaluated by electrical conductivity (EC), sodium percentage (Na%), sodium adsorption ratio (SAR), magnesium hazard (MH), and Wilcox diagram. The results indicated that the hydrochemistry of the GBRS was slightly alkaline to alkaline (7.42–8.78) in nature. The average concentrations of most of the chemical attributes showed higher in Group-1, whereas the average concentrations of K+ and NO3− were found higher in Group-2. The average concentration of the major ions followed the dominancy order Ca2+ > Mg2+ > Na+ > K+ for cations and HCO3− >SO42− > Cl− > NO3− for anions in both groups. Gibbs plot and mixing plot indicated that carbonate rock weathering dominates the hydrochemical process, which was further confirmed by the Piper diagram and the ionic ratios. From the analyses of irrigational water quality, almost all the rivers (except Gomti River in terms of MH and Rangit River in terms of Na%) in the GBRS were found to be suitable based on EC, SAR, Na%, MH, and Wilcox diagram. Finally, the majority of river systems in the GBRS were characterized by carbonate dominated lithology and irrigational water quality is mostly suitable for utilization. This study could be useful for water quality management in the glacial-fed Himalayan river under the context of global climate change.Electronic supplementary materialSupplementary material (Appendix 1) is available in the online version of this article at 10.1007/s11629-021-6834-z

The chemical analysis of 22 water samples collected from representative open dug-wells existing in the Mandsaur area of Madhya Pradesh, India, was carried out for evaluating the quality of irrigation water. For this purpose, its colour, odour, taste, pH, total hardness, electrical conductivity, ionic concentrations, and various other parameters were determined. The calculated values of per cent sodium, Kelley's ratio, sodium adsorption ratio, residual sodium carbonate and magnesium hazard indicate that except at a few places, the groundwater, in general, is suitable for irrigation.
 The sodium adsorption ratio and electrical conductivity values were plotted on the U.S. Salinity Diagram. The plots of these parameters indicate that 8 samples fall in CS type (Medium Salinity and Low Sodium hazards), and 14 samples belong to C type (High Salinity and Low Sodium hazards). In general, the groundwater is favourable for irrigation use. The values of electrical conductivity and sodium percentage determined in respect of groundwater samples of Mandsaur were also plotted on the Wilcox Diagram. Based on this diagram, 4 samples represent Excellent to Good categories, whereas 18 samples indicate Good to Permissible categories. Based on this classification the groundwater of Mandsaur area, in general, is suitable for irrigation application.

This study aims to assess the water quality of the Divanbaşı Pond and evaluate its suitability for irrigation. Monthly water samples were collected from four stations between June 2023 and May 2024. Seventeen physicochemical parameters were analyzed in accordance with the thresholds defined by the Surface Water Quality Regulation of Türkiye (SWQR) and the World Health Organization (WHO) Drinking Water Standards. Furthermore, the pond’s water quality was evaluated using several irrigation-related indices, including the Water Quality Index (WQI), Sodium Adsorption Ratio (SAR), Sodium Percentage (Na%), Magnesium Hazard (MH), Kelley Ratio (KR), and Residual Sodium Carbonate (RSC). The mean values recorded were 40.01 for WQI, 1.39 for SAR, 32.79% for Na%, 53.07 for MH, 0.47 for KR, and –4.60 for RSC. Overall, the findings suggest that the Divanbaşı Pond is generally suitable for irrigation purposes; however, the potential accumulation of Mg²⁺ should be monitored.

The degradation of groundwater (GW) quality due to seawater intrusion (SWI) is a major water security issue in water-scarce regions. This study aims to delineate the impact of SWI on the GW quality of a multilayered aquifer system in the eastern coastal region of Saudi Arabia. The physical and chemical properties of the GW were determined via field investigations and laboratory analyses. Irrigation indices (electrical conductivity (EC), potential salinity (PS), sodium adsorption ratio (SAR), Na%, Kelly’s ratio (KR), magnesium adsorption ratio (MAR), and permeability index (PI)) and a SWI index (fsea) were obtained to assess the suitability of GW for irrigation. K-mean clustering, correlation analysis, and principal component analysis (PCA) were used to determine the relationship between irrigation hazard indices and the degree of SWI. The tested GW samples were grouped into four clusters (C1, C2, C3, and C4), with average SWI degrees of 15%, 8%, 5%, and 2%, respectively. The results showed that the tested GW was unsuitable for irrigation due to salinity hazards. However, a noticeable increase in sodium and magnesium hazards was also observed. Moreover, increasing the degree of SWI (fsea) was associated with increasing salinity, sodium, and magnesium, with higher values observed in the GW samples in cluster C1, followed by clusters C2, C3, and C4. The correlation analysis and PCA results illustrated that the irrigation indices, including EC, PS, SAR, and MAR, were grouped with the SWI index (fsea), indicating the possibility of using them as primary irrigation indices to reflect the impact of SWI on GW quality in coastal regions. The results of this study will help guide decision-makers toward proper management practices for SWI mitigation and enhancing GW quality for irrigation.

Coastal groundwater is ubiquitously under threat due to a variety of natural and anthropogenic activities. Groundwater occurring along a stretch of the coastal tract (L = 15 km) of Thiruvananthapuram district, Kerala, India, was analyzed for hydrogeochemical characterization, identification of factors influencing water chemistry, suitability for drinking and irrigation purposes. A total of 48 water samples were collected over three sampling seasons (pre-monsoon – PRM, monsoon – MON and post-monsoon – POM) in 2012. The study area is sandwiched between two estuaries: the Akkulam–Veli estuary to the north and the Poonthura (Karamana River) estuary to the south, while a shore parallel man-made canal forms the eastern boundary on the landward side. The results of hydrogeochemical analysis showed that the parameters, such as electrical conductivity (EC), total dissolved solids (TDS) and total hardness (TH) are relatively higher in four locations towards the south due to proximity to the estuary/canal. Phosphate content exceeds the permissible limit for all samples in all sampling seasons. Water quality during POM is relatively good compared to other seasons. Hydrochemical facies of water samples suggests that groundwater samples belong to Ca-Cl type. Multivariate (R-mode) factor analysis identified a multitude of factors influencing groundwater chemistry. To assess the suitability of groundwater for irrigation use, different indices, viz., EC, percent sodium (%Na), sodium adsorption ratio (SAR), Kelley’s ratio (KR), residual sodium carbonate (RSC), permeability index (PI), and magnesium hazard (MH) were computed. The study reveals that the quality of groundwater is of concern, warranting attention. It is fit for drinking purpose only after amelioratory measures, whereas, it is permissible for irrigational purposes.

Assessment of hydrochemical shift in riverine aquifers of the mid-Gangetic plain of Uttar Pradesh, India

An integrated approach combining water quality indices (WQIs), multivariate data mining, and geographic information system (GIS) was employed to examine the water quality of Bheemasandra Lake, located adjacent to a sewage treatment plant (STP) in Tumakuru city, India. The analysis of 22 lake water samples, examined before and after the monsoons, revealed that the physicochemical parameters namely - electrical conductivity, biochemical oxygen demand, turbidity, total dissolved solids, ammoniacal nitrogen, nitrates, phosphates, magnesium, total hardness, total alkalinity, and calcium - exceeded the acceptable limits stipulated by national and international standards. The Canadian Council of Ministers of the Environment WQI (pre-monsoon: 25.3; post-monsoon: 33.9) and weighted arithmetic WQI (pre-monsoon: 3398; post-monsoon: 2093) designated the water as unsafe for drinking. Irrigation WQIs (sodium adsorption ratio, sodium percentage, residual sodium carbonate, magnesium hazard, permeability index, and potential salinity) implied water's suitability for irrigation. However, electrical conductivity indicated otherwise. Industrial WQIs (Larson-Skold Index, Langelier Index, Aggressive Index, and Puckorius Scaling Index) illustrated scaling propensity and the chloride sulfate mass ratio alluded galvanic corrosion potential. Hierarchical cluster analysis gathered 22 sampling points into two clusters (cluster 1: relatively lower polluted regions; cluster 2: highly polluted regions) for each season based on similarities in water features. Principal component analysis extracted four (79.07% cumulative variance) and six (87.14% cumulative variance) principal components before and after the monsoons, respectively. These components identified the primary pollution sources as urban sewage and natural lithological processes. WQI maps, created using the inverse distance weighted interpolation technique, enhanced the visualization of spatial-temporal variations. This study highlights the dire consequences of urbanization, STP pollution, and sewage management failures, necessitating that concerned authorities should implement policies and measures to curb the negative impacts on the environment and public health.

Tuticorin coastal city, Tamilnadu, India, has been selected to discuss the impact of pre-monsoon and post-monsoon on groundwater quality for irrigation in the region where agriculture is the main livelihood of the people and groundwater the main source of irrigation in the area. A total of 72 groundwater samples were collected and 13 water quality parameters were analyzed using standard procedures. It is observed that the major cations, Sodium played a dominant role in pre-monsoon (PRM) but in the post-monsoon (POM) period potassium was dominant. Among the major anions, sulphate played a dominant role in PRM, but in the POM period Chloride and Bicarbonate was dominant. The concentrations of the major ions are found to be high in the case of POM indicating leaching and anthropogenic activities predominates over dilution of the groundwater. From the Hill-piper plot was observed that the alkalies exceed the alkaline earths and strong acids exceed weak acids. In the case of anions, during the two periods strong acid shows dominance over weak acids during the both seasons. For assessing the groundwater for irrigation suitability parameters like total hardness, residual sodium carbonate, permeability index, sodium percentage, kelleys ratio, magnesium hazard and sodium adsorption ratio suggest that the groundwater of the study area is moderately suitable for irrigation purposes. Higher sodium adsorption ratio and magnesium hazard were noticed during POM indicating the effect of leaching and dissolution of salts into the aquifer matrix.

Integration of multivariate statistical analysis, geochemical modeling, and irrigation water quality assessment in the aquifers of the South-Atlas Tinghir-Errachidia-Boudenib basin (Pre-African Trough, Morocco)