Search Results (975)

Accurate estimation of actual evapotranspiration (ET) is critical for understanding hydrothermal cycles and ecosystem functioning in arid regions, where water scarcity governs ecological resilience. To address persistent gaps in ET quantification, this study integrates multi-source remote sensing data, energy balance modeling, and ground-based validation that significantly enhances spatiotemporal ET accuracy in the vulnerable desert steppe ecosystems. The study utilized meteorological data from several national stations and Landsat-8 imagery to process monthly remote sensing images in 2019. The Surface Energy Balance System (SEBS) model, chosen for its ability to estimate ET over large areas, was applied to derive modeled daily ET values, which were validated by a large-weighted lysimeter. It was shown that ET varied seasonally, peaking in July at 6.40 mm/day, and reaching a minimum value in winter with 1.83 mm/day in December. ET was significantly higher in southern regions compared to central and northern areas. SEBS-derived ET showed strong agreement with lysimeter measurements, with a mean relative error of 4.30%, which also consistently outperformed MOD16A2 ET products in accuracy. This spatial heterogeneity was driven by greater vegetation coverage and enhanced precipitation in the southeast. The steppe ET showed a strong positive correlation with surface temperatures and vegetation density. Moreover, the precipitation gradients and land use were primary controllers of spatial ET patterns. The process-based SEBS frameworks demonstrate dual functionality as resource-optimized computational platforms while enabling multi-scale quantification of ET spatiotemporal heterogeneity; it was therefore a reliable tool for ecohydrological assessments in an arid steppe, providing critical insights for water resource management and drought monitoring. Full article

Drought and water scarcity are some of the most important challenges facing agricultural producers in dry environments. This study aimed to evaluate the effect of algae extract and zeolite in terms of their biostimulant action on water stress tolerance to obtain better growth and production of tomato Lycopersicum esculentum L. grown in an open field under suboptimum and deficient soil moisture content. Large plots had a suboptimum soil moisture content (SSMC) of 25% ± 2 [28% below field capacity (FC)] and deficient soil moisture content (DSMC) of 20% ± 2 [11% above permanent wilting point (PWP)]; both soil moisture ranges were based on field capacity FC (32%) and PWP (18%). Small plots had four treatments: algae extract (AE) 50 L ha⁻¹ and zeolite (Z) 20 t ha⁻¹, a combination of both products (AE + Z) 25 L ha⁻¹ and 10 t h⁻¹, and a control (without application of either product). By applying AE, Z, and AE + Z, plant height, plant vigor, and chlorophyll index were significantly higher compared to the control by 20.3%, 10.5%, and 22.3%, respectively. The effect on relative water content was moderate—only 2.6% higher than the control applying AE, while the best treatment for the photosynthesis variable was applying Z, with a value of 20.9 μmol CO₂ m⁻² s⁻¹, which was 18% higher than the control. Consequently, tomato yield was also higher compared to the control by 333% and 425% when applying AE and Z, respectively, with suboptimum soil moisture content. The application of the biostimulants did not show any mitigating effect on water stress under soil water deficit conditions close to permanent wilting. These findings are relevant to water-scarce agricultural areas, where more efficient irrigation water use is imperative. Plant biostimulation through organic and inorganic extracts plays an important role in mitigating environmental stresses such as those caused by water shortages, leading to improved production in vulnerable agricultural areas with extreme climates. Full article

To address freshwater scarcity and the underutilization of low-saline water in the North China Plain, a field study was conducted to evaluate the effects of alternating sprinkler irrigation using saline and fresh water on soil water–salt dynamics and corn growth. Two salinity levels (3 and 5 g·L⁻¹, representing S1 and S2, respectively) and three irrigation strategies—saline–fresh–saline–fresh (F1), saline–fresh (F2), and mixed saline–fresh (F3)—were tested, resulting in six treatments: S1F1, S1F2, S1F3, S2F1, S2F2, and S2F3. S1F1 significantly improved soil water retention at a 30–50 cm depth and reduced surface electrical conductivity (EC) and Na⁺ concentration (p < 0.05). S1F1 also promoted more uniform Mg²⁺ distribution and limited Ca²⁺ loss. Under high salinity (5 g·L⁻¹), surface salt accumulation and ion concentration (Na⁺, Mg²⁺, and Ca²⁺) increased, particularly in S2F3. Corn growth under alternating irrigation (F1/F2) outperformed the mixed mode (F3), with S1F1 achieving the highest plant height, leaf area, grain number, and 100-grain weight. The S1F1 yield surpassed others by 0.4–3.0% and maintained a better ion balance. These results suggest that alternating irrigation with low-salinity water (S1F1) effectively regulates root-zone salinity and improves crop productivity, offering a practical strategy for the sustainable use of low-saline water resources. Full article

Drylands cover approximately 41% of Earth’s land surface, supporting about 500 million people and 45% of global agriculture. Groundwater is essential in drylands and is crucial for maintaining ecosystem services and offering numerous benefits. This article, for the first time, analyses and valuates the hydrological ecosystem services (HESs) provided by groundwater in a region of the Colorado River Delta in Mexico, an area with uncertain economic impact due to water scarcity. The main water sources are the Colorado River and groundwater from the Mexicali and San Luis Rio Colorado valley aquifers, both of which are overexploited. Valuation techniques include surrogate and simulated market methods for agricultural, industrial, urban, and domestic uses, the shadow project approach for water conservation and purification cost avoidance, and the contingent valuation method for recreation. Data from 2013 to 2015 and 2020 were used as they are the most reliable sources available. The annual value of HESs provided by groundwater was USD 883,520 million, with water conservation being a key factor. The analyzed groundwater uses reflect differences in efficiency and economic value, providing key information for decisions on governance, allocation, conservation, and revaluation of water resources. These results suggest reorienting crops, establishing differentiated rates, and promoting payment for environmental services programs. Full article

With increasing global challenges related to water scarcity and phosphorus depletion, the recovery and reuse of wastewater-derived nutrients offer a sustainable path forward. This study evaluates the dual role of lanthanides (Ce³⁺ and La³⁺) in recovering phosphorus from municipal wastewater and supporting corn (Zea mays) cultivation through lanthanide phosphate (Ln-P) and lanthanide-reclaimed wastewater (LRWW, wastewater spiked with lanthanide). High-purity precipitates of CePO₄ (98%) and LaPO₄ (92%) were successfully obtained without pH adjustment, as confirmed by X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS). Germination assays revealed that lanthanides, even at concentrations up to 2000 mg/L, did not significantly alter germination rates compared to traditional coagulants, though root and shoot development declined above this threshold—likely due to reduced hydrogen peroxide (H₂O₂) production and elevated total dissolved solids (TDSs), which induced physiological drought. Greenhouse experiments using desert-like soil amended with Ln-P and irrigated with LRWW showed no statistically significant differences in corn growth parameters—including plant height, stem diameter, leaf number, leaf area, and biomass—when compared to control treatments. Photosynthetic performance, including stomatal conductance, quantum efficiency, and chlorophyll content, remained unaffected by lanthanide application. Metal uptake analysis indicated that lanthanides did not inhibit phosphorus absorption and even enhanced the uptake of calcium and magnesium. Minimal lanthanide accumulation was detected in plant tissues, with most retained in the root zone, highlighting their limited mobility. These findings suggest that lanthanides can be safely and effectively used for phosphorus recovery and agricultural reuse, contributing to sustainable nutrient cycling and aligning with the United Nations’ Sustainable Development Goals of zero hunger and sustainable cities. Full article

Water scarcity is a key constraint for commercial Eucalyptus plantations, particularly given the increasing frequency of droughts driven by climate change. This study assessed annual transpiration (Tr) and water use efficiency (WUE) across eight genotypes subjected to contrasting irrigation regimes (WR). A split-plot design was implemented, comprising two irrigation levels: high (maintained above 75% of field capacity) and low (approximately 25% above the permanent wilting point). The genotypes included Eucalyptus globulus (EgH, EgL), E. nitens × globulus (EngH, EngL), E. nitens (En), E. camaldulensis × globulus (Ecg), E. badjensis (Eb), and E. smithii (Es). Between stand ages of 7 and 9 years (2020–2023), we measured current annual increment (CAI), leaf area index (LAI), Tr, and WUE. Under high WR, CAI ranged from 8 to 36 m³ ha⁻¹ yr⁻¹, Tr from 520 to 910 mm yr⁻¹, and WUE from 0.7 to 2.9 kg m⁻³. Low irrigation reduced CAI by 5–25% and Tr by 10–35%, while WUE responses varied across genotypes, ranging from a 12% decrease to a 48% increase. Based on their functional responses, genotypes were grouped as follows: (i) stable performers (Es, Ecg, Eb) exhibited high WUE and consistent Tr under both WR; (ii) partially plastic genotypes (EgH, EngH) combined moderate reductions in Tr with improved WUE; and (iii) water-sensitive genotypes (EgL, EngL, En) showed substantial declines in Tr alongside variable WUE gains. These findings underscore the importance of selecting genotypes with adaptive water-use traits to improve the resilience and long-term sustainability of Eucalyptus plantations in Mediterranean environments. Full article

Potatoes have high nitrogen (N) and irrigation requirements. Increasing water scarcity and environmental concerns highlight the need for efficient resource management. This study evaluated the effects of deficit irrigation and reduced N on yield and growth parameters in four potato cultivars (Canela Russet, Mesa Russet, Russet Norkotah3, and Yukon Gold) at Colorado State University’s San Luis Valley Research Center over two growing seasons. Three irrigation levels (~70%, ~80%, and 100% ET replacement) and two N rates (165 and 131 kg/ha) were evaluated. Measurements included total and marketable yield, tuber size distribution, tuber bulking (TB), leaf area index (LAI), and stem and tuber numbers. Yield losses were absent with ≤18% irrigation reduction in Canela Russet, Mesa Russet, or Yukon Gold but occurred with larger deficits. Russet Norkotah3 experienced yield decline with 16–23% reductions in irrigation. A twenty percent reduction in N application had no effect on Mesa Russet or Russet Norkotah3 yields, while the other varieties experienced a yield decline in one out of two years. Early-season LAI and late-season TB were positively correlated with yield, particularly for Canela Russet and Russet Norkotah3. These findings suggest irrigation and N inputs can be reduced without compromising productivity, but reductions must be determined on a cultivar-by-cultivar basis. Full article

Water scarcity, exacerbated by climate change, population growth, and competing sectoral demands, poses a major threat to agricultural sustainability, particularly in irrigated regions such as the Nile Delta in Egypt. Addressing this challenge requires innovative approaches to evaluate irrigation performance despite the limitations in ground data availability. Traditional assessment methods are often costly, labor-intensive, and reliant on field data, limiting their scalability, especially in data-scarce regions. This paper addresses this gap by presenting a comprehensive and scalable framework that employs publicly accessible satellite data to map crop types and subsequently assess irrigation performance without the need for ground truthing. The framework consists of two parts: First, crop mapping, which was conducted seasonally between 2015 and 2020 for the four primary crops in the Nile Delta (rice, maize, wheat, and clover). The WaPOR v2 Land Cover Classification layer was used as a substitute for ground truth data to label the Landsat-8 images for training the random forest algorithm. The crop maps generated at 30 m resolution had moderate to high accuracy, with overall accuracy ranging from 0.77 to 0.80 in summer and 0.87–0.95 in winter. The estimated crop areas aligned well with national agricultural statistics. Second, based on the mapped crops, three irrigation performance indicators—adequacy, reliability, and equity—were calculated and compared with their established standards. The results reveal a good level of equity, with values consistently below 10%, and a relatively reliable water supply, as indicated by the reliability indicator (0.02–0.08). Average summer adequacy ranged from 0.4 to 0.63, indicating insufficient supply, whereas winter values (1.3 to 1.7) reflected a surplus. A noticeable improvement gradient was observed for all indicators toward the north of the delta, while areas located in the delta’s new lands consistently displayed unfavorable conditions in all indicators. This approach facilitates the identification of regions where agricultural performance falls short of its potential, thereby offering valuable insights into where and how irrigation systems can be strategically improved to enhance overall performance sustainably. Full article

The Saiss plain in northern Morocco covers an area of 2300 km² and is one of the main agricultural contributors to the national economy. However, climate change and water scarcity reduce the region’s agricultural yields. Conventional methods of estimating evapotranspiration (ET) provide localized results but cannot capture regional-scale variations. This study aims to estimate the spatiotemporal evolution of daily crop ET (olives, fruit trees, cereals, and vegetables) across the Saiss plain. The METRIC model was adapted for the region using Landsat 8 data and was calibrated and validated using in situ flux tower measurements. The methodology employed an energy balance approach to calculate ET as a residual of net radiation, soil heat flux, and sensible heat flux by using hot and cold pixels for calibration. METRIC-ET ranged from 0.1 to 11 mm/day, demonstrating strong agreement with reference ET (R² = 0.76, RMSE = 1, MAE = 0.78) and outperforming MODIS-ET in accuracy and spatial resolution. Olives and fruit trees showed higher ET values compared to vegetables and cereals. The results indicated a significant impact of ET on water availability, with spatiotemporal patterns being influenced by vegetation cover, climate, and water resources. This study could support the development of adaptive agricultural strategies. Full article

Reusing and recycling treated wastewater is a sustainable approach to meet the growing demand for clean water, ensuring its availability for both current and future generations. Wastewater can be treated in such advanced ways that it can be used for industrial operations, recharging groundwater, irrigation of fields, or even manufacturing drinkable water. This strategy meets growing water demand in water-scarce areas while protecting natural ecosystems. Treated wastewater is both a resource and a challenge. Though it may be nutrient-rich and can increase agricultural output while showing resource reuse and environmental conservation, high treatment costs, public acceptance, and contamination hazards limit its use. Proper treatment can reduce these hazards, safeguarding human health and the environment while enhancing its benefits, including a stable water supply, nutrient-rich irrigation, higher crop yields, economic development, and community resilience. On the one hand, inadequate treatment may lead to soil salinization, environmental degradation, and hazardous foods. Examining the dual benefits and risks of using treated wastewater for agricultural irrigation, this paper investigates the complexities of its use as a valuable resource and as a potential hazard. Modern treatment technologies are needed to address these difficulties and to ensure safe and sustainable use. If properly handled, treated wastewater reuse has enormous potential for reducing water scarcity and expanding sustainable agriculture as well as global food security. Full article

This study explores the water harvesting systems of mgouds in southern Tunisia and boqueras in southeastern Spain to understand their adaptation to semi-arid conditions and geomorphic contexts. These systems use ephemeral water through medieval-origin infrastructures to increase the water supply to rainfed crops. The hypothesis is that the diversity of these systems stems from environmental rather than cultural factors. By employing a qualitative–analytical approach, this study compares concentrated runoff diversion systems to investigate the use of boqueras/mgouds in terraces and glacis in the arid and semi-arid areas of Tunisia and the southeastern Iberian Peninsula. The research involved performing detailed geomorphological and climatological analyses and comparing structural complexities and water management strategies across different regions. The results indicate significant variability in system size and complexity. Tunisian mgouds are typically simpler and more individualised, while Spanish boqueras are larger and more complex due to more frequent and intense torrential rainfall. No common patterns were identified between the two regions. This study reveals that both types of systems reflect sophisticated adaptations to manage water scarcity and mitigate the impacts of intense rainfall, with geomorphic and climatic factors playing a decisive role. The primary conclusion is that the design and functionality of these water systems are predominantly influenced by environmental conditions rather than cultural factors. This research provides insights for developing sustainable water management strategies in other semi-arid regions. Full article

Increasing water scarcity in arid regions has prompted the mining industry to develop strategies to maximize water recovery and reuse, especially in tailings treatment processes. In this context, the present investigation evaluated the effects of sodium polyacrylate (NaPA) on the compressibility and viscoelasticity of clayey tailings in the presence of hard water containing calcium and magnesium. To this end, clayey slurries were analyzed using rheological tests (rheograms and oscillatory viscoelasticity), zeta potential measurements, and compressibility tests using batch centrifugation. The yield stress was determined using the Herschel–Bulkley model, while the compressive yield stress (Py(Φ)) was calculated as a key indicator to characterize the degree of sediment consolidation. The results showed that NaPA, due to its anionic nature and high degree of ionization at pH 8, induces effective particle dispersion by increasing electrostatic repulsion and decreasing the interaction force between particles, which reduces both rheological parameters and compressive yield stress. For the 70/30 quartz/kaolin mixture, the yield stress decreased from 70.54 to 61.64 Pa in CaCl₂ and from 57.51 to 52.95 Pa in MgCl₂ in the presence of NaPA. It was also observed that suspensions in the presence of magnesium ions presented greater compressibility than those with calcium, attributable to the greater hydration radius of magnesium (10.8 Å), which favors less dense and more easily deformable network structures. Furthermore, a higher proportion of kaolin in the mixture resulted in higher yield stresses, a product of the clay’s laminar structure, colloidal size, and high surface area, both in the absence and presence of NaPA. Overall, the results show that incorporating NaPA significantly improves the compressibility and rheology of clayey tailings in hard water, offering a promising alternative for optimizing water recovery and improving tailings management efficiency in the context of water restrictions. Full article

Rural landscapes play a key role in preserving ecological processes, cultural identity, and socio-economic well-being, yet these areas often face challenges such as land degradation, water scarcity, and an inadequate road network. A sustainable approach to rural landscape and tourism planning is essential for enhancing both environmental resilience and socio-economic vitality in areas facing degradation and global change. This study aims to develop and validate an integrated methodological workflow that combines Landscape Character Assessment (LCA), ECOVAST guidelines, SWOT analysis, and open-source GIS techniques, complemented by a bottom-up approach of spontaneous fruition mapped through Wikiloc heatmaps. The framework was applied to a case study in Paternò, Eastern Sicily, Italy—a territory distinguished by its key local values such as Calanchi formations, proximity to Mount Etna, and cultural heritage. Through this application, eight distinct Landscape Units (LUs) were delineated, and key strengths, weaknesses, opportunities, and threats for sustainable development were identified. Using open-access data and a survey-free protocol, this approach facilitates detailed landscape assessment without extensive fieldwork. The methodology is readily transferable to other rural Italian and Mediterranean contexts, providing practical guidance for researchers, planners, and stakeholders engaged in sustainable tourism development and landscape management. Full article

Decentralized desalination systems driven by renewable energy sources have surfaced as a feasible way to alleviate water scarcity in arid and rural areas. This bibliometric study aims to clarify the research trends, conceptual frameworks, and cooperative dynamics in the scientific literature on decentralized renewable-powered desalination techniques. Using a thorough search approach, 1354 papers were found. Duplicates, thematically unrelated works, and entries with poor information were removed using the PRISMA 2020 framework. A selected 832 relevant papers from a filtered dataset were chosen for in-depth analysis. Quantitative measures were obtained by means of Bibliometrix; network visualisation was obtained by means of VOSviewer (version 1.6.19) and covered co-authorship, keyword co-occurrence, and citation structures. Over the previous 20 years, the data show a steady rise in academic production, especially in the fields of environmental science, renewable energy engineering, and water treatment technologies. Author keyword co-occurrence mapping revealed strong theme clusters centred on solar stills, thermoelectric modules, reverse osmosis, and off-grid systems. Emphasizing current research paths and emerging subject borders, this paper clarifies the intellectual and social structure of the field. The outcomes are expected to help policy creation, cooperative projects, and strategic planning meant to hasten innovation in sustainable and decentralized water desalination. Full article

Inefficient agricultural water use is a significant factor exacerbating global water scarcity. Water rights trading (WRT) offers a new governance paradigm to address this issue. Initiated by China in 2014, the WRT policy provides a case for researching formal water markets in developing countries. This paper uses a sample of 30 Chinese provinces from 2007 to 2022 and employs the difference-in-differences method to evaluate the impact of WRT on agricultural water use efficiency (AWUE). The findings suggest that AWUE in pilot areas increased by an average of 48.1% compared to non-pilot areas. Heterogeneity analysis reveals a stronger WRT impact on AWUE in regions with developed markets, abundant water, and high agricultural dependence. Subsequent analysis identifies that WRT enhances AWUE mainly by incentivizing water-saving innovation, promoting cross-industry factor mobility, and optimizing crop structures. This study thus offers empirical evidence supporting China’s water marketization reform and explores WRT policy as a pathway to enhance AWUE. Full article