Irrigation Wells Research Articles

Irrigation Water in Northwest Syria: Impact of the Recent Crisis and Drought

This study examines how Northwest Syria’s arable and irrigated areas are changing, with a particular emphasis on processes that have affected cultivation and water availability since 2011. A substantial decline in cultivated areas is revealed by the analysis of 502 samples from various stakeholders, including farmers, well owners, well-digging companies, agricultural pharmacies, and service offices. District-specific variations show a decrease of 15.3% and 8.5% in total cultivated land and irrigated areas, respectively. Particularly in areas known for their summer vegetables and winter crops, such Al-Bab and Jebel Saman, agricultural productivity has drastically decreased since 2011. Today, 67% of irrigation comes from groundwater wells, especially in Jabal Saman and Idleb, whereas Jisr-Ash-Shugur depends on the Orontes River. Due to drought and a lack of regulatory oversight, the number of irrigation wells has risen since 2011, severely reducing water supplies and driving up irrigation prices. High fuel and electricity costs, uncontrolled well drilling, broken machinery, and insufficient irrigation systems are some of the main obstacles. A lot of well owners would rather sell drinking water, which would cut down on irrigated land and crop cultivation. The needs of the stakeholders include subsidies for fuel and electricity, the development of alternative energy, well repairs, improvements to irrigation systems, the provision of agricultural inputs, and better local water management. This study emphasizes the critical need for focused interventions to support agriculture and livelihoods in Northwest Syria and offers significant insights for sustainable water management solutions.

Occurrences of nitrate-contaminated groundwater in the piedmont aquifers: hydrogeochemical characteristics and health risks.

Groundwater nitrate (NO3-) contamination is a global concern. The distribution patterns, enrichment mechanisms, and human health risks of NO3- contaminated groundwater were investigated using 144 groundwater samples collected from domestic and irrigation wells in the piedmonts of the North China Plain (Beijing and Shijiazhuang areas). The results showed that the groundwater was neutral to weakly alkaline, and 47% of the groundwater samples had NO3- concentrations exceeding 50mg/L, a threshold proposed by world health organization to threaten infants up to 3months. Groundwater NO3- concentrations were generally higher in the Beijing piedmont than in the Shijiazhuang piedmont and decreased with depth in both piedmonts. High-NO3- (> 50mg/L) groundwater was distributed sporadically spatially and mainly was of Ca-Mg-HCO3 hydrochemical facies. Stable isotopes (D and 18O) compositions and NO3-/Cl- ratios indicated that NO3- accumulation in groundwater was primarily due to use of N-fertilizers under agricultural practices, and was associated with groundwater recharge sources such as septic tank leakage and re-infiltration of reclaimed irrigation water. Water quality evaluation showed that groundwater quality was highly dependent on NO3- concentration, with entropy-weighted water quality index values increasing linearly with increasing NO3- concentrations. The potential health risk of high-NO3- groundwater was the most serious for infants in both the piedmonts. Therefore, reducing NO3- input from sources and drinking water intake is recommended to minimize the human health risk.

Study on mapping method of irrigated cultivated land–taking Nebraska as an example

The distribution information of irrigated cultivated land is important to many studies, including grain yield estimation, water resources management, drought risk assessment, and so on. This study developed a feature variable, called the irrigation probability index (IPI), based on the principle that irrigation can slow down or inhibit the evolution from meteorological drought to agricultural drought. Nebraska, which has a good irrigation information database, was selected as the study area. Combining IPI with the irrigation statistical data and other selected feature variables, irrigated cultivated land in Nebraska was mapped in 2017 using both the spatialization method and remote sensing classification methods (random forest and support vector machine). We verified the effectiveness of IPI in identifying irrigated cultivated land, analyzed the importance of different feature variables for irrigated cultivated land identification, and compared the accuracy of different irrigation mapping methods. The results show that the IPI is significantly correlated with the actual irrigation area, the area of irrigation facilities, and the number of active irrigation wells. It has a better indicative ability of irrigation in areas with a suitable climate or arid areas, than in areas with a humid climate. The crop water stress index (CWSI), IPI, vegetation index (EVI and NDVI), and land surface temperature difference between day and night are the most important feature variables that are used to distinguish irrigated cultivated land from rain-fed cultivated land. There are differences between the recognition accuracies of the three mapping methods in different climatic regions. Overall, the spatialization method had the highest accuracy (overall accuracy = 86.92 %, kappa = 0.74) and the highest similarity with the existing high-resolution irrigation maps. This study provides a direct and useful reference for other researchers to select feature variables and mapping methods in irrigated cultivated land mapping research.

Small dams drive Anopheles abundance during the dry season in a high malaria burden area of Malawi.

This study explores the influence of small dams on the exposure to malaria vectors during the dry season in Kasungu district, Malawi, an area recently identified as high priority for malaria interventions by the National Malaria Control Programme. Small dam impoundments provide communities with a continuous supply of water for domestic and agricultural activities across sub-Saharan Africa and are considered vital to food security and climate change resilience. However, these permanent water bodies also create ideal breeding sites for mosquitoes in typically arid landscapes. The study focuses on a specific dam impoundment and its vicinity, aiming to assess its spatial and temporal influence on indoor vector densities. From May to August 2021, CDC light traps were used to measure indoor mosquito densities for two consecutive nights per month in three communities located at increasing distances from the dam (0, ~1 and ~2 km). Simultaneously, drone imagery was captured for each community, enabling the identification of additional standing water within approximately 400 m of selected households. Larval sampling was carried out within the impoundment periphery and in additional water bodies identified in the drone imagery. Generalised linear mixed models (GLMMs) were employed to analyse the indoor Anopheles abundance data, estimating the effects of household structure (open/closed eaves), month, temperature and water proximity on malaria vector exposure. Throughout 685 trapping nights, a total of 1256 mosquitoes were captured, with 33% (412) being female Anopheles. Among these, 91% were morphologically identified as Anopheles funestus s.l., and 5% as Anopheles gambiae s.l. Catches progressively decline in each consecutive trapping month as the environment became drier. This decline was much slower in Malangano, the community next to the dam, with abundance being notably higher in June and July. Further, the majority of An. gambiae s.l. were caught in May, with none identified in July and August. Anopheles larvae were found both in the impoundment and other smaller water bodies such as irrigation wells in each survey month; however, the presence of these smaller water bodies did not have a significant impact on adult female mosquito catches in the GLMM. The study concludes that proximity to the dam impoundment was the primary driver of differences between survey communities with the abundance in Chikhombwe (~1 km away) and Chiponde (~2 km away) being 0.35 (95% confidence interval [CI], 0.19-0.66) and 0.28 (95% CI, 0.16-0.47) lower than Malangano, respectively, after adjusting for other factors. These findings underscore the importance of targeted interventions, such as larval source management or housing improvements, near small dams to mitigate malaria transmission risks during the dry season. Further research is needed to develop cost-effective strategies for vector control within and around these impoundments.

Groundwater vulnerability zonation using Aplis and Foster method in The Ponorogo-Ngawi groundwater basin

In 2021, Ngawi district became the largest rice producer in East Java. Groundwater is the main water source used for irrigation purposes. Lack of management for developing necessary irrigation wells has resulted in uncontrolled groundwater use, potentially reducing groundwater quantity and quality. This study aims to analyze groundwater vulnerability zones. An assessment was conducted using the Aplis and Foster methods, and their parameter classes can be customized to match the conditions of the research area. The Aplis method considers five parameters: altitude (A), slope (P), lithology (L), infiltration (I), and soil (S). The Foster method considers four parameters: aquifer response characteristics (RA), aquifer storage characteristics (DS), aquifer thickness (s), and groundwater depth (h). The vulnerability values obtained using the Aplis method ranged from 30 to 131 and were divided into four classes: low, moderate, high, and very high. The Vulnerability values obtained using the Foster method ranged from 10 to 15 for the low and moderate classes. A non-technical approach through the strict application of permits and restrictions on groundwater usage is a basis for formulating policies related to groundwater management in the research area.

Using Machine Learning Models to Forecast the Conversion Coefficient between Electricity Consumption and Water Pumped for Irrigation Wells in Baicheng City, China

Forecasting the electricity-to-water conversion coefficient (EWCC) can help manage and plan irrigation water in arid and semiarid areas. However, the EWCC is influenced by several factors, making it difficult to develop an analytical model for validation or prediction. Therefore, this study selected 206 typical irrigation wells in Baicheng City to conduct EWCC tests in a field investigation to gather information regarding the results and related influencing factors. Subsequently, machine learning models (multiple linear regression model, support vector model, and backpropagation neural network) were trained, validated, and tested, and their precisions were evaluated and compared. The backpropagation neural network model was the most accurate, followed by the support vector and multiple linear regression models. The backpropagation neural network model results were consistent with those of the field survey, and this model was thus used to forecast the EWCC for all the townships in Baicheng City. The forecasting models revealed that most towns had an EWCC from 3 to 7 m3/kW·h, with an EWCC greater than 7 observed in the Tao’er River Fan and Yueliangpao District. The BP models developed in this study proved to be dependable and applicable for forecasting the EWCC in this area.

Exploitation technology and productivity analysis of hydrothermal geothermal multi-branch wells

At present, hydrothermal geothermal mining mainly adopts wells recharge mode, and the structure of production and irrigation wells are mainly vertical wells, which rarely used in related horizontal wells. Moreover, domestic hydrothermal geothermal injection and production technology have low productivity and low utilization potential, so it is urgent to carry out corresponding research and tackle key problems of new technologies such as branch wells to improve the development potential and utilization value of geothermy. In this work, the mining scheme and productivity of heat storage branch wells in Guanzhong Basin are analyzed and studied by numerical simulation. Aiming at the distribution of geothermal resources in Guanzhong Basin, a geothermal branch wells scheme was proposed, and the influence of horizontal wells branch number, branch direction and location, branch wells structure and other factors on the productivity of the whole mining system were studied. The results show that the heat recovery power of multi-branch wells not only increases by 60 % compared with that of vertical wells structure in the case of this work, but also improves recharge and recovery effectively. The heat recovery power of the fishbone lateral horizontal wells was increased by about 30 % during its life cycle. The effects of multi-lateral wells structure parameters on productivity and thermal diffusion were systematically analyzed to further clarify the optimization direction of heat reservoir lateral wells structure.

Arsenic accumulation pattern in water-soil-rice systems: A study of tolerance mechanisms and associated health risks

Regardless of the daunting challenge of arsenic (As) contamination in Pakistan, literature on tolerance and responsible factors in paddy fields remain elusive. In this regard, we aimed to explore physiochemical factors responsible for As availability in water-soil-rice systems. The study highlighted rice defense mechanisms to mitigate As toxicity on growth and yield. In the present study, basmati rice samples were collected along with irrigation and soil samples from control (<10 μg/L), low (11–25 μg/L), medium (26–100 μg/L), and high (>100 μg/L) contaminated regions. Oxidative stress markers (MDA and H2O2) and antioxidant enzymatic assays (SOD, CAT, POD, APX) were measured by spectrophotometer. The Durov diagram was constructed by using Grapher software to identify prevalent water types in irrigation wells. Total As was measured in water, soil, and rice tissues by hydride generation-atomic absorption spectroscopy (HG-AAS). The Durov diagram showed that the majority of irrigation water was Ca-Mg-Cl type. Furthermore, the FTIR analysis identified different organic compounds, i.e., OH, CC, CI, and CBr, particularly in soil from high regions. The results indicated higher accumulation and translocation of As in the water-soil-rice system from a high region compared to control and other regions. Phenotypic traits, i.e., grain yield, biological yield, chlorophyll, and root parameters were significantly impacted under high As-contaminated region. A concentration-dependent increase was indicated in oxidative stress and antioxidant activities except for APX. Risk assessment indicated a higher hazard quotient (1.09) and carcinogenic risk (5.0 × 10−03) due to grain consumption in high As-contaminated regions. The present study emphasized the need for strict regulations and policies to mitigate As calamity at the local level and protect human health.

A new decision-making method for the renewal of agricultural irrigation wells: A case study of Songzhuang town, Tongzhou District, Beijing

Pumping wells (PWs) lie at the core of agricultural irrigation infrastructure, and their spatial configuration is of great significance for the scientific management of regional agriculture and rational use of water resources. To solve the problems of unreasonable and unscientific spatial allocation of regional agricultural irrigation PWs, this paper proposes a new strategy for updating agricultural irrigation PWs based on a spatial decision model, using Songzhuang Town, Tongzhou District, Beijing as a case study. The model utilizes constraints based on local factors such as actual land use, and proposes a novel feasible solution strategy that combines random local search and abrupt jumps to increase the probability that feasible solutions will be found, addressing the performance issues of simulated annealing algorithms, influence of initial values, and parameter sensitivity. Finally, we used the proposed method to perform updated decision analysis on the spatial configuration of PWs in the study area. The results showed that most of the crops in the study area lack irrigation, and the currently available PWs cannot meet the needs for irrigation. The new PWs added based on this decision method can be more evenly distributed within the predefined optimization unit. The proposed number of PWs to be added is 166, the density of PWs is 0.04/ha, and the crop area covered by the PWs is 3350.43 ha. In contrast to the previous PW layout, the optimized PW configuration can meet the irrigation needs of residents, indicating that the new method proposed in this paper has good potential for extension and application.

Cost-Effectiveness of Sustainable Agricultural Water Policies: Source Switching versus Irrigation Buyout Auctions in Georgia’s Lower Flint River Basin

In this paper, a new methodology for comparing the cost-effectiveness of sustainable agricultural water policies during times of drought is developed. The methodology explicitly accounts for regional economic impacts from policy implementation and uncertainty related to drought frequency. The methodology is applied to two policy options being considered by the state of Georgia in the lower Flint River basin: irrigation buyout auctions and source switching. The results demonstrate the following: (1) the importance of modeling uncertainty associated with both the frequency and timing of drought, and the hydrologic effects of source switching; (2) as the frequency of drought increases, the cost-effectiveness of irrigation buyout auctions decreases. Failure to incorporate the regional economic impacts of each policy significantly underestimates the costs of both, but more so for irrigation buyout auctions than source switching. The ability to proactively manage the uncertainty associated with source switching through research and the judicious site selection of new irrigation wells increases its cost-effectiveness.

Telecoupled urban demand from West African cities causes social-ecological land use transformation in Saharan oases.

Little is known about the long-distance telecoupling effects of urban food demands on land use changes (LUCs) in remote oases of the Southern Sahara. Using the example of two typical oasis settlements on Mont Bagzam in the southern Aϊr Mountains of Niger which are linked to regional and global markets by an unpaved road since 2015, this study aimed at analyzing time trajectories of LUCs and related changing agricultural production patterns. LUCs were quantified for 1955 to 2022 using GIS-based mapping of agriculture and natural vegetation based on historical aerial photographs, CORONA and multi-spectral satellite images, and high resolution drone-based surveys. The results show a major increment in actively used agricultural land in the 850 ha watershed of the two oases from 11 ha in 1955 to 13 ha in 2003 and 68 ha in 2022 as well as the addition of 92 irrigation wells to 16 existing ones between 2003 and 2022. LUCs and evapotranspiration calculated from climatic data of a local weather station allowed to estimate changes of irrigation water needs in the selected watershed. While annual precipitation averages only 214 mm, local reference evapotranspiration may reach 1,476 mm year-1. Therefore, the additional annual irrigation water needs for the newly established fields between 2003 and 2022 cultivated to cash crops rose by 696 million l. To detect LUC effects on soil quality, soil samples of onion and garlic fields of different ages were collected employing a false-time-series approach. Results reveal increasing soil pH and salt concentrations and falling ground water tables, which reflects a negative water balance and ground water extraction above recharge levels. Our study provides evidence that the newly established telecoupled production systems on Mont Bagzam threaten the sustainability of existing local agricultural production and related livelihoods of agro-pastoralists.

Study on the Law of the Electric Folding Water Coefficient in Chayuo Middle Banner

In this paper, based on the investigation and research of groundwater types, topography and geomorphology, geological structure, stratigraphic lithology, groundwater richness and agricultural irrigation wells in the area of Chayou Middle Banner Inner Mongolia, a test area is selected and typical wells are determined. The estimating water consumption of typical wells was measured. Based on the calculation results, the distribution map of the Electricity-to-water conversion factor was drawn, and the influence of groundwater type on the Electricity-to-water conversion factor was analyzed. The results show that the type of groundwater has a significant impact on the number of electric water conversion factors, and the electric water conversion coefficients of fracture pore pressure water and groundwater in Neoproterozoic clastic rocks are relatively large; The electric water conversion coefficient of pore and fissure water pressure and groundwater in Neoproterozoic basalt ranks second; Quaternary loose rock pore water average; The bedrock fissure water is the smallest. At the same time, the influence of topography, atmospheric precipitation, and agricultural production on the Electricity-to-water conversion factor under the same type of groundwater was preliminarily investigated.

Arsenic Contamination in Groundwater, Soil and the Food-Chain: Risk Management in a Densely Populated Area (Versilia Plain, Italy)

This study deals with arsenic distribution in groundwater, soil and edible vegetables in the densely populated area of the Versilia Plain (Tuscany region, Italy), addressing potential impacts on people’s health. The data revealed high As concentrations in some domestic irrigation wells, exceeding 1200 µg/L. The average As concentration in topsoil and subsoil was 39 and 46 mg/kg, respectively, with the highest concentration reaching about 200 mg/kg. Arsenic concentrates in plant roots compared with the edible parts; in tomato fruits, black cabbage leaves and edible leek parts As reached about 0.2 mg/kg, 0.4 mg/kg and 3 mg/kg, respectively. Geochemical and hydrostratigraphic data suggest that As in soils and alluvial sediments originated from mineralized and historical upstream mining areas. The exposure routes for both non-carcinogenic and carcinogenic risk assessment here considered include soil ingestion, dermal absorption, soil dust inhalation and vegetable consumption. For non-carcinogenic and carcinogenic effects, the hazard was higher than the acceptance threshold. The calculated soil screening levels resulted even lower than the guideline soil-concentration imposed by Italian regulations, and this poses an issue on the actual meaning of arsenic regulatory thresholds.

Hydrogeological Hazards in Open Pit Coal Mines–Investigating Triggering Mechanisms by Validating the European Ground Motion Service Product with Ground Truth Data

This research focuses on the investigation of hydrogeological hazards in open pit coal mines. The study area is the Amyntaio sub-basin area, located in West Macedonia prefecture, Greece. A major part of the SE of this area is occupied by the Amyntaio open pit coal mine. In recent decades, the Amyntaio basin’s aquifer has been overexploited both by dewatering wells of the open pit coal mine and irrigation wells, triggering extensive land subsidence in an area that extends 3 km around the mine. Additionally, one of the biggest mining landslides worldwide occurred on the South-West slopes of the open pit on 10 June 2017. The current study investigates the land subsidence phenomenon and the landslide, highlighting the influence and the interaction of their causal factors which were strongly affected by the groundwater management. To estimate ground surface movement, Earth Observation data from the European Ground Motion Service, of the Copernicus European Union′s Earth observation program, were used for the period 1 January 2016–31 December 2020. The geologic, geotechnical and hydrogeologic data coming from the extensive ground truth survey have been incorporated with the Earth Observation data, highlighting the opposing mechanisms of the interacting geohazards.

Agri-Inputs Consumption Patterns, Access, and Delivery Mechanism in India

The Government of India has initiated several programs to provide timely inputs to farmers with special subsidies on regular inputs such as seed material, fertilizers, irrigation, animal purchase, etc. These inputs are supplied through various mechanisms such as government departments, agricultural universities, KVKs, NGOs, local shop owners, producer's associations etc. Studying the agri-inputs available and their supplying mechanisms in India provides clarity on the status of farmers and the number of farmers who benefi ted from diff erent services provided by GOI. A survey questionnaire was developed to collect data from the 14 states with a sample size of 409 farmer respondents and was administered to the Foundation course for Agricultural Research Service (FOCARS)-82 batch, who were undergoing fi eld experience training (FET) at ICAR-NAARM, Rajendranagar, Hyderabad, Telangana State. The survey revealed that most farmers felt satisfi ed with the quality of seed, followed by agrochemicals and chemical fertilizers. Among all the assets, farmers spent the most money on purchasing animal feed (INR 46047.05) followed by planting material- saplings (INR 34445.07) and adult draught animals (INR 31805.07). The maximum number of respondents specifi ed that storage facility for grains, electricity, and byproducts were suffi ciently available. More money is spent on purchasing the recurrent associated input, i.e., irrigation sprinkler/drip, followed by irrigation wells. The Maximum number of farmers has access to Common Property Resources (CPRs) such as pasture land, irrigation sources, threshing fl oors, water harvesting structures, producer's associations, selfhelp groups, and primary cooperative society. About 269 farmers availed credit facilities; among them, 103 farmers took a credit of &gt;10,000-50,000, which was majorly used for input purchase (240 farmers responded). About 132 farmers said they receive subsidies on seed/propagating material, fertilizer/agrochemicals, and irrigation. Most farmers received quality seed/propagating material from the local shop owners, followed by neighboring farmers, govt. departments and private companies. Very few are using/visiting Agricultural Universities, KVKs, cooperatives, NGOs, Agri-clinics, producers' associations, and village panchayats for seed purposes. In terms of credit suppliers, farmers listed public sector banks fi rst, followed by cooperative society credit cards and moneylender. Farmers with medium-sized land holdings have a better chance of availing subsidies compared to small-category farmers. Most small landholders need more opportunities to access agricultural credit. An adequate supply of timely inputs and support of low-cost credit from institutional sources is of great importance to small and marginal, farmers who contribute almost 60 per cent of total food grain production in India. The output of this study would become a benchmark for future assessments and decision-making in the fi eld of agri-inputs.

Water Cooperation and Ideology in Local Communities

This article addresses how ideology affects local water governance, focusing on a groundwater basin in central Iran. It offers a case study of a symbiotic relationship between upstream and downstream communities, allowing a sustainable form of water governance. The cooler weather, better pastures and greater amount of precipitation of the basin upstream drew nomadic communities, whose economy was not dependent on irrigation. Downstream, fertile soil and warm weather favored agriculture with a high demand for water that was supplied by the groundwater transferred from the basin upstream. The exchange of livestock products and agricultural goods between the basin’s upstream and downstream areas systematically tied their economic systems. However, Iran’s 1979 revolution brought a hybrid leftist-Islamist ideology that unbalanced this traditional relationship through the reorganization of geographical space. The upstream communities were encouraged to cultivate their pastures, which led to a boom in the number of irrigation wells. The downstream villages were persuaded to adopt a new cropping pattern that turned most of their water-efficient vineyards into apricot orchards with high water demands. Therefore, an abrupt increase in water demand in the basin upstream and downstream thwarted the cooperation between the two areas and drove the basin into “the tragedy of the unmanaged commons.”

Determining of radioactivity and the accompanying radiological hazards in the sediments of the Euphrates River and wells in Babylon governorate – Iraq

The radioactivity and radiological hazards associated with sediment samples collected from 13 locations along the Euphrates River as well as 12 associated irrigation wells were tested using a high-purity germanium system (HPGe). The radioactivity of isotopes 226Ra, 232Th, and 40K (Iso-RTK) in these sites exceed the worldwide limits, which makes them a human health risk. The estimated radiological parameters of the Euphrates and the well sediments exceed the radium equivalent (RE), absorbed dose rate (ADR), annual effective dose external (AEDE), internal - external hazards indices (IEHI), , and gamma index (Iy) . The radioactivity ​​of 238U and 232Th (Iso-UT) are constant along the Euphrates River; 40K (Iso-K) concentrations are elevated after the Hindyia barrage and exceed worldwide limits.

Modelling groundwater flow in the Plaine du Nord–Massacre shallow aquifer, Haiti

To assist in the sustainable management of water resources, a groundwater model of the shallow groundwater in the Plaine du Nord–Massacre transboundary aquifer system was developed. The Plaine du Nord–Massacre Aquifer is one of the largest aquifer systems of Haiti, supposedly bearing a high potential for water supply and irrigation. The shallower part is already tapped by hundreds of domestic wells and hand-pumped public and private boreholes. In the framework of the AVANSE project (Appui à la Valorisation du Potentiel Agricole du Nord, pour la Sécurité Économique et Environnementale), a USAID funded project aiming at developing sustainable agriculture in the region, a groundwater model was built to assist in decision making. The finite-difference-based MARTHE software was used for the model. Due to the lack of monitoring data, the calibration of the model could only be carried out under steady-state hydraulic conditions. It should thus be considered as a first step towards a better characterisation of the aquifer’s potential. However, the model computed a groundwater balance at the scale of the aquifer showing that significant water resources can be easily mobilized if one carefully manages to rule out local operational difficulties. The simulated groundwater drawdowns using transient simulation of irrigation scenarios are pluri-metric, reaching 6–7 m. New irrigation wells must be deeper than the current average depth of wells to support agricultural development projects.

Electrical resistivity tomography and induced polarization study for groundwater exploration in the agricultural development areas of Brunei Darussalam

Electrical resistivity tomography and induced polarization studies were conducted for groundwater exploration in eight selected agricultural sites in Brunei Darussalam. The study was undertaken to meet the growing demands for water supply in the agricultural sector, particularly for paddy field irrigation purposes. This study conducted nineteen surveys with lengths of up to 800 m and a depth of investigation of up to 150 m below ground level. 2D inverted resistivity and chargeability models delineated subsurface geological formations and aquifer zones in the study area. Aquifer zones were detected in all the investigated sites, with resistivity values ranging from 1 to 100 Ω m and chargeability values ranging from 0 to 10 ms. Based on the resistivity and chargeability interpretations, two new groundwater wells were drilled and constructed in two of the investigated sites. Borehole drilling encountered aquifer zones primarily in sand and sandstone layers. Hydraulic tests of the newly drilled boreholes revealed groundwater yields of 4.3 and 288 m3/day. Transmissivity values of the aquifer units estimated using the Cooper–Jacob time-drawdown solutions are 0.53 and 109 m2/day, while their hydraulic conductivity values are 0.05 and 2.75 m/day, respectively. Our findings suggest weak to moderate groundwater yield for withdrawal and distribution for irrigation purposes in the investigated sites. The present study helped decision-makers take suitable measures for placing future groundwater irrigation wells and achieve significant groundwater exploration results in the study area and other areas with similar geological settings.

Nebraska Irrigation Well Survey: Nutrient Supply and Liming Effects

A comprehensive survey of Nebraska’s irrigation wells in 2020 yielded extensive georeferenced water quality data, including essential nutrient supplies and liming effects. These data show irrigation well water properties may vary greatly, even between nearby wells, indicating that occasional sampling of individual irrigation wells can help producers optimize soil management and crop input decisions. Earn 0.5 CEUs in Soil &amp; Water Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/999.