Groundwater Irrigation Research Articles

Climate change and farmers' perception in Sivakasi taluk, India: a nexus and a suggestion for sustainable water reuse

Abstract Climate change poses a major threat to agriculture and food security, especially in developing countries where farmers depend on rainfall and groundwater for irrigation. This paper investigates how farmers in Sivakasi taluk, Tamil Nadu, India perceive and respond to climate change – rainfall and temperature – and its impacts on agriculture. Actual rainfall and temperature data are analyzed using Mann–Kendall test and Sen's slope estimator test, and the results are compared against the farmers' perceptions obtained through a questionnaire survey. The trend analysis showed an insignificant decrease in rainfall and a significant increase in temperature. Most farmers perceived rainfall change correctly, but not temperature change. It is found that water scarcity is a major challenge for agriculture due to reduced rainfall, increased temperature, and inadequate adaptations. To address this challenge, water reuse is proposed as a sustainable alternate adaptation that involves using treated wastewater (TWW) from a decentralized sewage treatment plant for irrigation. An index named Water Reuse Index (WRI) is developed to estimate the fraction of TWW that can replace freshwater irrigation. This study provides insights into farmers' perception of climate change and suggests a novel way to enhance water security and resilience in agriculture.

Policy Over Practice: A Review of Groundwater Governance Research in Sub-Saharan Africa

Groundwater is increasingly seen as crucial to both agricultural and domestic water supply in sub-Saharan Africa. Citing climate change and growing populations, there is especially a notable shift towards promoting groundwater for irrigation to ensure food security. Increased use of the resource will undoubtedly be accompanied with new questions of governance, with groundwater overexploitation in other parts of the world functioning as a strong cautionary tale. This article provides an overview of the current groundwater governance literature on sub-Saharan Africa. Using a critical water governance lens we analyse how groundwater governance is framed, what terms, categories, and measurements are used to describe and assess groundwater governance, and whose perspectives are considered. We also assess whether groundwater governance research has taken place across sub-Saharan African countries in a balanced way. We find that groundwater governance research in sub-Saharan Africa, even more so than elsewhere, ignores the voices and perspectives of those physically encountering the resource. Instead, it is dominated by the views of formal, technical groundwater experts focusing on the need for more hydrogeological data and formal policies. While the existing contributions to the literature are valuable, the current bias in perspectives calls for others to join the field of groundwater governance and to supplement current conceptualisations and approaches with those of users and others dealing with groundwater management on a daily basis. We argue that groundwater users’ practical governance experiences, locally adapted solutions and knowledges, can add important complementary perspectives and insights towards crafting effective, sustainable and equitable groundwater governance processes across the continent.

Irrigation Water Management in a Water-Scarce Environment in the Context of Climate Change

Climate change has a considerable impact on irrigated agriculture, which is vital for food and fiber production. In this study, in the context of climate change, simulation model CROPWAT 8 was employed to compute the reference evapotranspiration, and net irrigation water requirement for wheat, barley, maize, sugar beet, potato, tomato, and date palm. In addition, the WaterGEMS model was utilized to design a new sprinkler irrigation system to run long-term simulations of hydraulic behavior within pressurized pipe networks to irrigate 43 acres for two arid sites (Siwa Oasis and West Elminya fields) inside the 1.5-million-acre groundwater irrigation project in the Egyptian western desert. Five scenarios for climate change were employed in the current (1991–2023), representative concentration path (RCP) 8.5 greenhouse gas emission scenarios for the 2040s, 2060s, 2080s, and 2100s. Mean ETo values for the current scenario show 4.56 and 5.7 mm for the Siwa Oasis and West Elminya fields, respectively. The climate changes cause an increase of the reference evapotranspiration by 4.6, 5.9, 9.4, and 12.7% for RCP: 8.5 greenhouse gas emissions for the 2040s, 2060s, 2080s, and 2100s scenarios, respectively, for the Siwa Oasis field. On the other hand, an increased ratio for the reference evapotranspiration by 4.2, 5.4, 8.6, and 11.6% was observed for the scenarios in the West Elminya field, respectively. The designed sprinkler system indicated a capacity of 111.4 m3 h−1 and 167 m3 h−1 for Siwa and West Elminya fields, respectively. The study suggests using crop patterns for wheat, barley, potato, and sugar beet to save irrigation water.Graphical abstract

Risks from solar-powered groundwater irrigation.

Emissions reductions may not meet expectations, and groundwater use will likely increase.

Response of Evapotranspiration, Photosynthetic Characteristics and Yield of Soybeans to Groundwater Depth

To clarify the physiological mechanism of different groundwater depths affecting soybean evapotranspiration, photosynthetic characteristics and yield, a field experiment with four groundwater depth levels (1 m (D1), 2 m (D2), 3 m (D3) and 4 m (D4)) was conducted through the groundwater simulation system in 2021 and 2022. In this study, a quantitative analysis was conducted on the groundwater recharge and irrigation water demand and evapotranspiration (ET) of soybean fields with different treatments, and the effects of different treatments on soybean leaf area index (LAI), chlorophyll content index (SPAD), intercepted photosynthetic active radiation (IPAR), photosynthetic gas exchange parameters, dry matter accumulation (DMA) and yield were explored. The results showed the following: (1) Groundwater depth affected soybean ET and the source of ET. With the increase in groundwater depth, groundwater recharge and its contribution to ET gradually decreased, but the amount of irrigation required gradually increased, resulting in the ET as D1 > D4 > D2 > D3. (2) Soybean LAI, SPAD and IPAR were significantly affected by the different groundwater depths, of which the D1 treatment always maintained the maximum, followed by the D4 treatment, and the D3 treatment was the minimum. The photosynthetic gas exchange parameters under different treatments changed synergistically, showing significant differences in the flowering and podding stages, notably D1 > D4 > D2 > D3. Soybean DMA and yield first decreased and then increased with the increase in groundwater depth, and the average DMA and yield under the D1 treatment increased by 27.71%, 46.80% and 22.82% and 20.29%, 29.91% and 12.83% in the two years, respectively, compared to the D2, D3 and D4 treatments. (3) The structural equation model demonstrated that the groundwater depth indirectly affected the growth of soybean leaf area by affecting groundwater recharge, which in turn regulated soybean ET and photosynthetic capacity and ultimately affected DMA and yield. The above results showed that in the case of shallow groundwater depth (D1), the largest groundwater recharge promoted the growth of soybean leaf area and chlorophyll synthesis and increased the absorption and utilization of solar radiation. And it improved the leaf stomata conditions, accelerated the gas exchange between the plant and atmosphere, enhanced the photosynthetic production capacity and ET and achieved maximum DMA and yield. Soybean leaf growth and photosynthesis diminish with the increase in groundwater depth. In the case of deep groundwater depth (D4), the maximum irrigation improved the growth and photosynthetic performance of soybean leaves, which was favorable to ET, and ultimately led to increases in DMA and yield.

Groundwater Quality Assessment and Irrigation Water Quality Index Prediction Using Machine Learning Algorithms

The evaluation of groundwater quality is crucial for irrigation purposes; however, due to financial constraints in developing countries, such evaluations suffer from insufficient sampling frequency, hindering comprehensive assessments. Therefore, associated with machine learning approaches and the irrigation water quality index (IWQI), this research aims to evaluate the groundwater quality in Naama, a region in southwest Algeria. Hydrochemical parameters (cations, anions, pH, and EC), qualitative indices (SAR,RSC,Na%,MH,and PI), as well as geospatial representations were used to determine the groundwater’s suitability for irrigation in the study area. In addition, efficient machine learning approaches for forecasting IWQI utilizing Extreme Gradient Boosting (XGBoost), Support vector regression (SVR), and K-Nearest Neighbours (KNN) models were implemented. In this research, 166 groundwater samples were used to calculate the irrigation index. The results showed that 42.18% of them were of excellent quality, 34.34% were of very good quality, 6.63% were good quality, 9.64% were satisfactory, and 4.21% were considered unsuitable for irrigation. On the other hand, results indicate that XGBoost excels in accuracy and stability, with a low RMSE (of 2.8272 and a high R of 0.9834. SVR with only four inputs (Ca2+, Mg2+, Na+, and K) demonstrates a notable predictive capability with a low RMSE of 2.6925 and a high R of 0.98738, while KNN showcases robust performance. The distinctions between these models have important implications for making informed decisions in agricultural water management and resource allocation within the region.

Hydrochemical Characteristics and Suitability Assessment of Groundwater Quality for Irrigation

The hydrochemical properties of groundwater play a crucial role in crop growth and soil health, as well as the maintenance of irrigation equipment. To ensure suitable water quality for irrigation, the present study was conducted to evaluate the hydrochemical properties of irrigation groundwater in a typical agricultural region of Serbia. Groundwater was sampled at three monitoring locations in the Srem region in Republic of Serbia between 2011 and 2020. Examined parameters included electrical conductivity (EC), total dissolved salts (TDS), pH values, and the concentrations of cations (sodium (Na+), calcium (Ca2+), magnesium (Mg2+) and potassium (K+)) and anions (bicarbonate (HCO3−), chloride (Cl−), sulfate (SO42−), and nitrate (NO3−)). Further assessment was done using three classification systems; Nejgebauer’s, the US USSL, and the FAO classification. To obtain a more detailed assessment, additional indices were included, such as Soluble Sodium Percentage (SSP), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly’s Ratio (KR), Magnesium Adsorption Ratio (MAR), and Total Hardness (TH). The PCA analysis detected that the concentration of K+, Ca2+, and Na+ in the irrigation water were lower in recent years, while the concentration of Cl− was higher. The cluster analysis grouped the parameters into three clusters; I—electroconductivity, II—dry residue and HCO3−, and III—other water parameters for all three monitoring localities. According to the applied classifications, the majority of underground water samples were suitable for irrigation. However, some samples fell out of the range of the first class, indicating the need for regular water quality monitoring. In light of climate changes that influence water deficiency, the urgent need for wise and sustainable water use implies the application of a comprehensive approach to irrigation water quality assessment, as shown in this study.

The degradation of a nonylphenol isomer in water and soil of typical sewage irrigation area in China

AbstractNonylphenols (NPs), one of the known endocrine disrupting organic pollutants, had received full attention for their estrogenic potency and ubiquitous distribution in the environment. Due to its chemical properties and compositions of technical nonylphenols (tNPs), which was persistent and soil environments for a long time and affect the ecosystem vigorously, degradation behaviour of a nonylphenol isomer (NP38) and the para‐substituded nonylphenols (4‐NPs) in water and soil was compared in this study. The results showed that the 4‐NPs and NP38 could be degraded under the mercury lamp in ultrapure water, 90% of 4‐NPs and NP38 were photodegradated in 2 h, but the removal rate of the 4‐NPs was slightly faster than the NP38. The NP38 was almost completely decay under the UV in 120 min. The active species (NO3− and Fe3+) were benefit for the photogradation of NP38 and presented higher efficiency under the higher concentration. The biodegradable curves of the 4‐NPs and NP38 in the SS (The soil from sewage irrigation area) were similar, 84% of the NP38 was removed after 20 days later in SS, the 62.25% of the NP38 was remained after 60 days later in CS (the soil was from the groundwater irrigation area), but the removal rate of the NP38 was nearly two times to the 4‐NPs in the CS, and the structure of the nonylphenol isomers with α‐quaternary had influenced on its degradation in soils. The study was helpful for better understanding the migration and transformation behaviour of NPs and provided scientific basis for accurate assessment of environmental risk of NPs from the sewage irrigation area.

The Groundwater Resources in the Mazovian Lowland in Central Poland during the Dry Decade of 2011–2020

This article addresses the issue of droughts in recent years in Poland and their impact on the state of groundwater resources. This paper presents the challenges arising from the increasing demand for the use of groundwater for irrigation in agriculture, supplementing water shortages, and potential threats to the water supply of rural waterworks. The main part of this paper focuses on a small catchment area in the Mazovian Lowland, which is one of the driest regions in the country. This article includes definitions, characteristics, and causes of hydrologic and hydrogeologic droughts during the period 2011–2020. In the discussed area, there is generally one groundwater level of the Quaternary age, primarily recharged by rainfall infiltration, which is utilized by all dug wells and a number of drilled wells. The source material consisted of daily measurements of groundwater levels with a free surface from three piezometers located in different land use areas (forest, agricultural, and sparse development). Additionally, daily flows of the Zagożdżonka River at the Płachty Stare gauge station were examined, where the drying of the riverbed in the upper reaches has been observed in recent years. This study investigated the dynamics of hydrogeologic droughts in renewable groundwater resources and the rate of their decline in relation to hydrologic droughts of surface waters.

Groundwater levels, climate and anthropogenic factors affect the hydrology and water quality of an intermittent and a regulated subtropical stream

AbstractStream hydrology and water quality are highly interconnected and impacted by climate, land use and geology. We examined this connection using monitoring data from 2000 to 2019 for two streams with contrasting hydrological regimes—intermittent and regulated perennial—in subtropical Queensland, Australia. Our main objective was to evaluate relationships between groundwater levels, climate and flow regulation on the hydrology and water quality of an intermittent and a regulated subtropical stream. In intermittently flowing Lockyer Creek, flow was highly dependent on groundwater levels and occurred when the aquifer was recharged to elevations exceeding the upper 90‐percentile value. With 9.4% of the catchment area in irrigated horticulture, flow in Lockyer Creek was also likely to be reduced by drawdown of the aquifer for irrigation, with no flow for 30% to 81% of days over the observation period for stations in Lockyer Creek. In contrast, flow in the mid‐Brisbane River was continuous, regulated by discharge from a large upstream dam. Nutrient and suspended sediment concentrations in Lockyer Creek were generally higher than in the mid‐Brisbane River, likely associated with runoff from agricultural areas adjacent to the stream, while the upstream dam likely reduced the concentration and variability of nutrients and suspended sediment in the mid‐Brisbane River. During periods of low flow in the mid‐Brisbane River, longitudinal changes in nutrient and suspended sediment concentrations occurred, notably a significant decrease in total and dissolved inorganic nitrogen concentrations downstream (p < 0.05), indicating a possible effect of in‐stream algal uptake and denitrification. This study highlights the impact of human modifications on stream hydrology and water quality in the face of climate change. The findings can inform decision‐making on groundwater irrigation or dam release control for water security.

Analysis of the effect of climatic variability and increasing water demand on the Saïss aquifer, Morocco

Climate variability has a significant impact on the water table of the Saïss plain, which relies heavily on groundwater for agricultural irrigation and drinking water supply. The study of the spatio-temporal evolution of the groundwater level requires a global and integrated approach that considers both natural processes and human activities. Satellite imagery has provided information on land use and land cover that influences groundwater recharge. The GIS has facilitated the integration of different datasets, allowing spatial analysis, mapping and identification of vulnerable areas to depletion. Geostatistical techniques are used to analyze collected data, identify trends and quantify the relationship between groundwater levels and various influencing factors. The results of this study have shown that the depth of the water table of the Saïss plain between 2000 and 2020 has generally decreased by several metres in the NW and the centre zone, but has improved by a few metres or remained constant in the other areas. This information is valuable for developing sustainable water management plans that take into account both environmental and societal needs.

Evaluating the suitability of groundwater for irrigation in parts of mid-Gangetic plains, Bihar

Irrigation water quality is critical for crop production. The present study focuses on assessment of suitability of groundwater for irrigation purposes in four blocks of Samastipur district, Bihar lying in the mid Gangetic plains. In this district most of the people are dependent upon agriculture.

Characteristics and Influence Factors of Soil Water and Salt Movement in the Yellow River Irrigation District

Climate change and human activities lead to freshwater shortage, soil salinization, and food security crises in arable land. To explore the natural and irrigation factors on soil water and salt movement, this study quantitatively analyzed the dynamic characteristics of soil water and salt movement under precipitation, groundwater irrigation, and brackish water irrigation conditions for the next 30 years using Hydrus-1D model-based parameters obtained from the winter wheat–summer maize rotation experiments in the Yellow River Irrigation District. The results showed that precipitation was the key factor of climate change affecting soil water and salt migration, especially in the 0–20 cm soil layer. Under both SSP585 and SSP245 climate scenarios, rainfall in normal and wet years promoted salt leaching up to 1 m below the surface soil. But in dry years, salt washing treatment was required for the tillage layer to prevent salt accumulation. The higher the groundwater level was, the higher the soil water and salt content was in the 0–100 cm soil layer. In this soil layer, a 2 m groundwater level contributed 30% to wheat water needs, while a 3 m groundwater level contributed 18%, and no significant contribution was observed for a 4 m groundwater level. The salinity of the soil profile showed an overall increasing trend with irrigation using 1–3 g/L brackish water for 30 years. However, the salinity in the 0–100 cm soil layer was below the salt tolerance threshold of winter wheat and summer maize with salts accumulated in the 1–2 m soil layer. Considering the salinization of the root zone and crop water needs, it is recommended that the safe groundwater level for brackish water irrigation should be 3 m in the study region. This study provides scientific reference for groundwater–farmland ecosystems to utilize brackish water and treat saline–alkali lands.

Irrigation and nitrogen fertiliser optimisation in protected vegetable fields of northern China: Achieving environmental and agronomic sustainability

Globally, sub-optimal use of nitrogen (N) fertiliser and elevated N irrigation groundwater have led to high leached nitrate (NO3−) losses from protected vegetable field systems. Optimising fertiliser and irrigation management in different soil types is crucial to reduce future N loads from such systems. The present 4-year study examined leached N loads from lysimeter monitoring arrays set up across 18 protected vegetable system sites encompassing the dominant soil types of northern China. The treatments applied at each field site were: 1) a high N and high irrigation input treatment (HNHI); 2) a low N but high irrigation input treatment (LNHI) and 3) a low N with low irrigation input treatment (LNLI). Results showed that the mean annual leached total nitrogen loads from the HNHI, LNHI and LNLI treatments were 325, 294 and 257 kg N ha−1 in the fluvo-aquic soil, 114, 100 and 78 kg N ha−1 in the cinnamon soil and 79, 68 and 57 kg N ha−1 in the black soil, respectively. The N dissolved in irrigation water in the fluvo-aquic soil areas was 8.26-fold higher than in the cinnamon areas. A structural equation model showed that N fertiliser inputs and leaching water amounts explained 14.7 and 81.8% of the variation of leached N loads, respectively. Correspondingly, reducing irrigation water by 21.5% decreased leached N loads by 20.9%, while reducing manure N and chemical N inputs by 22 and 25% decreased leached N loads by only 9.5%. This study highlights that protected vegetable fields dominated by fluvo-aquic soil need management to curtail leached N losses in northern China.

Soil moisture forecasting for precision irrigation management using real-time electricity consumption records

The installation of the smart electricity meters (SEMs) to the high-density pumping wells in the North China Plain (NCP) provided a method to control the groundwater withdraw. The record in real-time electricity consumption from SEMs also provided an alternative method to forecast soil moisture to make irrigation decisions to improve irrigation efficiency. The irrigation timing and the irrigation amount could be obtained on-line from the SEMs based on the coefficients obtained for electricity-to-water conversion (E-Wc). The real-time recordings in the irrigation timing and amounts were further used to forecast the next irrigation timing and amount based on the water rights per area of land, the lower limit of soil water contents for different crops at their different growing stages and online meteorological data. A smartphone app was developed based on this framework. The running of the app to simulate soil water contents based on the soil water balance equation was supported by databases on soil texture, crop coefficients, water rights, E-Wc and threshold soil water content values as well as the real-time collection of electricity consumption and meteorological data. The simulated real-time soil water contents were shown on the mobile phone screen and could be compared with the threshold values for making irrigation decisions for users. The accuracy in forecasting the soil water contents using the methods developed in this framework was tested under different irrigation schedules for winter wheat and summer maize during 2018–2019 and 2021–2022, and the app was tested for three locations starting from sowing winter wheat in October 2022 to April in 2023. The results showed that the app could be easily run, and precise real-time soil water contents were simulated. With the application of the pumping well renovation project in the NCP, most of the pumping wells were installed with the SEMs, and using SEMs for groundwater pumping control and irrigation decisions should be possible.

Surface temperature adjustment in METRIC model for monitoring crop water consumption in North China Plain

Evapotranspiration is the real water consumption element in agricultural water management. In order to improve the efficiency of agricultural water use and maintain the sustainable development of agriculture, more and more attention has been paid to the improvement of monitoring and management of farmland evapotranspiration. In this study, MODIS data and the Temperature Vegetation Dryness Index (TVDI) were used in the METRIC model to estimate evapotranspiration for winter wheat and summer corn in the North China Plain. In order to decrease the error caused by the spatial heterogeneity of air temperature in the estimation of evapotranspiration, based on the characteristics of cold pixels with surface temperatures close to their air temperature, the TVDI was used to assist the selection of cold pixels and obtain the spatial variation trend of air temperature with latitude from all cold pixels in the study area. The influence of the spatial heterogeneity of air temperature on the surface temperature at the time of the satellite overpass was corrected accordingly, thereby the estimation accuracy of evapotranspiration was improved. A METRIC-TVDI model was established and the evapotranspiration of winter wheat and summer corn in Hebei Plain was estimated from 2017 to 2019. The average evapotranspiration of the winter wheat over these three years were 361 mm, 327 mm and 354 mm respectively, and that of summer corn were 394 mm, 388 mm and 405 mm respectively. Based on the farmland water balance, the irrigation water consumption (evapotranspiration minus precipitation) of winter wheat and summer corn rotation were 324 mm, 134 mm and 360 mm respectively. This kind of crop rotation pattern consumed more groundwater for irrigation, especially the winter wheat. In order to realize the balance of groundwater between exploitation and replenishment in Hebei Plain, more water-saving irrigation technologies should be adopted to reduce the evapotranspiration and improving water use efficiency.

The role of changing land use and irrigation scheduling in groundwater depletion mitigation in a humid region

Many agricultural production regions in the world have been experiencing groundwater resource depletion, which threatens water and food security if mitigation practices are not developed and implemented. To understand how changing land use and irrigation schedule impact groundwater, a coupled SWAT-MODFLOW model was applied to determine groundwater depletion mitigation strategy in a humid region, the Big Sunflower River Watershed (BSRW) in Mississippi, USA. It was found that converting grasslands to forests contributed to reducing groundwater declining. Simulated results indicated that the watershed lost 749, 586, and 381 mm yr−1 of water through surface runoff in the wet, normal and dry years, respectively. The amount of groundwater that moved into the vadose zone to help satisfy crop water demand ranged from 700 to 750 mm yr−1. Precipitation increased the groundwater recharge during the rainy season from fall to spring. Annual recharge rate was only 34–50 mm. Groundwater level dropped 0.2–0.5 m in crop irrigation seasons (May to August). Land use dataset showed 81 % of the area is cropland, with soybean, corn, rice, and cotton accounting for 64 % of the total cropland area in BSRW. The planted area of corn and soybean significantly increased while the area of cotton area was tremendously reduced. Corn, soybean, and rice consumed approximately 96 % of the total amount of groundwater irrigation. This study indicated that irrigation scheduling based on plant water demand could save 47 % of groundwater currently used by conventional irrigation. The improved irrigation schedule could reduce groundwater decline by 0.01–2.05 m across the watershed, and mitigate the declines by 1.35–2.05 m in the depression cone in the central east part of the watershed. The results can assist with planning land and water use and developing sustainable groundwater management practices focused on locations of high groundwater withdrawals in other regions around the world.

Impact of Groundwater Depletion on Irrigation Cost of Paddy and Maize Cropping System in the Anantapur District of Andhra Pradesh, India

The study was conducted to estimate the cost of groundwater irrigation and the impact of groundwater over-exploitation on the irrigation cost of paddy and maize in the Anantapur district of Andhra Pradesh. Based on the stage of groundwater extraction, the Central Groundwater Board divided the study area into safe and exploited areas. Primary data was collected from both these safe and exploited areas. The study found that the annual irrigation cost of groundwater in over-exploited areas for both paddy (₹4033.38/acre) and maize (₹3570.26/acre) were observed to be higher as against paddy (₹2697.01/acre) and maize (₹ 2524.76/acre) in safe areas. The added cost of groundwater irrigation in over-exploited areas for paddy (₹988.08/acre) and maize (₹838.34/acre) were preponderantly greater than paddy (₹216.60/acre) and maize (₹187.82/acre) in safe areas. This revealed that groundwater over-exploitation had a more significant impact on over-exploited regions. Marginal and small farmers are the primary victims of groundwater over-exploitation in terms of cost and groundwater resources. Free/subsidized electricity for irrigation and water-intensive crops, paddy and maize, are one of the reasons for depleting groundwater in the study area. There is a solid requirement for controlling groundwater over-exploitation in the study area.

Estimación de la disponibilidad a pagar en dos acuíferos en Baja California, México

This study presents an assessment of the perceptions and willingness-to-pay (WTP) of farmers using groundwater for irrigation in two aquifers in northern Baja California, Mexico. Contingent Valuation (CV) measured their WTP to ensure availability of groundwater in the future. Data from surveys of 70 and 54 farmers in the Maneadero and Guadalupe valleys, respectively, were combined and analyzed using logistic regression. Farmer WTP is influenced by variables reflecting “present water scarcity for agricultural use”, “education and family income levels”, “partial use of wastewater for irrigation”, “water quality”, and “payment amount”. A WTP estimate of $US 0.13/m3 suggests that the environmental cost of depleting aquifers over a 20-year span could reach $US 17.4-24.9 million for the Guadalupe aquifer and $US 20.50 million for the Maneadero aquifer. This information could serve as a starting point to help decision makers in northern Mexico design more environmentally sustainable pricing policies, including investing revenues in long-term aquifer restoration.

Assessment of groundwater suitability for drinking and irrigation purpose using statistical and geospatial techniques

Water is a vital source for all living individuals on earth. The consumption of fresh water has increased rapidly in recent years. Industrialization, urbanization, and population growth have resulted in deterioration of surface and groundwater quality. It is very important to manage groundwater resources and protect them from anthropogenic activities in order to sustain life on earth. This paper discusses methods for assessing the quality of groundwater using statistical and geospatial techniques. In addition, geographic information system (GIS)-integrated statistical methods are also discussed. Statistical methods, including quality indices, irrigation water quality parameter, and geospatial methods, including inverse distance weighted (IDW) and kriging strategies for evaluating groundwater quality and assessing aquifer susceptibility are also explained. In addition, the paper provides an overview of key groundwater quality indices (GWQI) and irrigation water quality indices (IWQI) that have developed over time and used for groundwater quality evaluation around the world. It is revealed that the use of GIS-integrated advanced statistical approaches is not common in assessments of groundwater quality. The constraints and research gaps of previous studies, as well as the prospects for future research needs have been examined.