The security of the water-energy-food (WEF) nexus is vital for regional sustainability yet constrained by complex inter-subsystem couplings and conflicts between subjective and objective weighting schemes. Taking Hubei Province as the research area, this study proposes a hybrid weighting approach integrating fuzzy analytic hierarchy process (FAHP), entropy weighting and game theory for WEF security assessment. A comprehensive evaluation index system covering water resources, energy and food subsystems is constructed. Based on 2006–2022 panel data, indicator weights are determined by the hybrid weighting method, and the relative security levels are quantified via the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Results show that Hubei’s WEF system security presents a fluctuating upward trend, with the composite score rising from 0.332 in 2006 to 0.638 in 2022, an overall increase of 92.2
Previous studies highlighted the effectiveness of Low Impact Development (LID) practices in reducing urban surface runoff, but their long-term performance at different implementation areas remains unclear. This study addresses this gap by simulating surface runoff reduction and its implications on the stormwater drainage system of the Universidade Federal de Lavras, Brazil, evaluating five LID practices—bioretention cell, rain garden, infiltration trench, permeable pavement, and vegetative swale—implemented across 10
Surface water quality governance in developing economies frequently fails to reverse long-term deterioration despite successive legislative interventions, yet rigorous quantitative evaluation of policy effectiveness at the basin scale remains rare. This study applies a transferable six-method analytical framework to 48 years (1978–2026) of monitoring data from ten São Paulo river basins, Brazil, comprising 646,356 physicochemical records from 141 stations. Five legislative milestones are evaluated, from the 1997 National Water Resources Policy to the 2020 Legal Sanitation Framework. A nine-parameter water quality index was computed over the full record, with the 2012 microbiological-indicator transition handled by continuity to avoid a spurious discontinuity. Seasonal–trend decomposition revealed heterogeneous rather than uniform trajectories: five basins show negative trend slopes and five positive (− 0.67 to + 0.42 index units per year), with the metropolitan Tietê corridor degrading while reservoir and peri-urban basins improve. Changepoint analysis identified structural breaks temporally proximate to legislative milestones, but only the creation of the National Water Agency (2000) shows a robust degradation-leaning signal; two milestones are statistically indistinguishable from null, and one window is confounded by the index transition and reported as non-interpretable. Spatial autocorrelation is positive and significant throughout but non-monotonic, peaking in the 2012–2019 period. Copula analysis showed that joint pollutant exceedance probabilities exceed univariate expectations, and machine-learning forecasts project divergent basin trajectories to 2030. Because the framework establishes temporal coincidence rather than causation, it identifies where change accompanied legislation without attributing that change to legislation alone.
Sustainable irrigated agriculture in semi-arid regions increasingly requires crop planning according to water availability rather than only farmer preference or short-term profitability. This study develops a governance-aware, scheme-scale nonlinear optimization framework for drought-oriented crop planning in a centrally managed irrigation system in Türkiye. The model maximizes total net income by allocating crop areas and crop-specific irrigation-water depths under land, seasonal surface-water, crop-bound, and income-feasibility constraints. Two planning settings are evaluated: a flexible income-maximizing benchmark with selected dry-farming alternatives and a policy-constrained scenario with crop-area caps for diversification and institutional implementability. CROPWAT-derived deficit-irrigation response points were used to construct crop-specific water–income functions under historically observed drought conditions. The 2016–2022 diagnostic showed declining supply adequacy, with the Water Supply Ratio decreasing from 1.36 to 0.42. The flexible scenario generated higher income, whereas the capped scenario produced a more diversified crop pattern with a modest reduction in income and water economic productivity. KKT-based diagnostics and a piecewise-linear local-slope check supported the internal consistency of the optimized allocations. The findings indicate that optimization-based crop planning can support rule-based drought management in Water User Associations. A scheme-scale nonlinear optimization framework was developed for drought-oriented crop planning. Crop area and irrigation-water depth were optimized under land, water, and crop-bound constraints. Flexible and policy-constrained scenarios quantified the profitability-implementability trade-off. KKT and piecewise-linear diagnostics supported the internal consistency of the optimized solutions. Declining WSR during 2016-2022 highlighted the need for rule-based drought planning. Supplemental groundwater use should be monitored within formal WUA allocation strategies.
We characterize surficial seawater physico-chemical conditions and dissolved CO2 dynamics at the active volcanic system of Deception Island (Antarctica), with emphasis on identifying hydrochemical plumes associated with shallow sea hydrothermal vents (SHV). During the austral summers of 2024 and 2025, spatial surveys of pH, temperature, salinity, and total alkalinity were conducted along the inner coast of Port Foster. Acidification plumes (down to pH 6.1), carbonate undersaturation, and elevated total alkalinity (2,400–7,000 μmol kg⁻1) were identified in areas affected by volcanic–hydrothermal emissions. Dissolved CO2 reached up to 90,000 μatm, with extreme values approaching 160,000 μatm, far exceeding atmospheric equilibrium. The results reveal a strong tidal control on CO2 dynamics in Port Foster, with low tide conditions enhancing nearshore accumulation and potential outgassing. Fluid compositions suggest mixed contributions from hydrothermal inputs, seawater, and meteoric components. These findings highlight the value of carbonate system parameters for detecting and monitoring SHV activity, and position Deception Island as a natural laboratory to investigate volcanic impacts on coastal ocean acidification under polar conditions.
Urban Nature Reserves (UNRs) are green areas that promote, among other things, water quality protection. A physicochemical characterization of water and sediments was carried out in four UNRs in the City of Ushuaia: Laguna del Diablo (UNR_LD), Ecológico (UNR_ECO), Hol Hol (UNR_HH), and Bahía Encerrada (two sites: UNR_ABE and UNR_BE). In the water samples, in situ parameters such as pH, electrical conductivity, and dissolved oxygen were measured, while in the laboratory, turbidity, total solids, suspended solids, alkalinity, hardness, chlorides, dissolved nutrients, chlorophyll-a and coliform bacteria were analyzed. The highest nutrient levels were recorded in the UNR Bahía Encerrada, with ammonium peaks in UNR_BE (0.48 mg/L) and nitrate and phosphate peaks in UNR_ABE (0.61 mg/L and 0.15 mg/L, respectively). Total and fecal coliform bacteria exceeded the values established in the local regulation for recreational use, indicating that sewage pollution is still active, along with the accumulation of organic matter in sediments. Toxicity bioassays with lettuce seeds satisfactorily complemented the water and sediment analysis results. Monitoring these green spaces is an important management tool, to rethink allowed uses in UNRs, to create or update their management plans, and aid decision-making for a sustainable urban management.
Springs are the primary water source for Himalayan communities, yet their sustainability is threatened by climate change and land-use shifts. Precipitation infiltrates fractured rock and re-emerges as spring flow, but physically based models are limited by scarce lithological data, while data-driven approaches often lack long-term discharge records for predicting this process. This study leverages rare multi-decadal observations from the Senchal Springshed near Darjeeling, Eastern Himalayas, to assess rainfall–spring discharge linkages under climate and forest-cover change. A long short-term memory (LSTM) model was trained with rainfall as input and discharge as output for two contrasting phases: a forested period (2008–2023) and a deforested phase (1987–1994) following abrupt forest clearing. Future rainfall scenarios applied to both models project a 15–20
This study investigates submarine groundwater discharge in intertidal flats along the Patagonian coast, characterizing its geochemical composition at four sites representing different environmental settings (Puerto Lobos, Riacho San José, Puerto Madryn, and Cerro Avanzado). Shallow groundwater was sampled from piezometers during low tide, and physicochemical parameters (pH, electrical conductivity, 222Rn) were measured alongside major ion analyses. The results indicate that, although groundwater within the intertidal flats exhibits a sodium–chloride signature typical of seawater, variations in major ion concentrations (Cl⁻, Na⁺), and radon activity (222Rn) provide evidence of heterogeneous groundwater inputs from adjacent coastal environment. These differences are attributed to geomorphological diversity (e.g. salt marshes, dunes, and spits), as well as to anthropogenic influences and local hydrogeological conditions. The results highlight the importance of integrating geomorphological analysis with hydrochemical and isotopic tracers to interpret variations in groundwater discharge in macrotidal intertidal environments.
Water scarcity and increasing agricultural demand necessitate efficient irrigation systems; however, many schemes in Ethiopia operate below their design capacity. This study assessed the hydraulic performance of the Shawe Gindiba Gojo irrigation scheme in Bale Zone of Oromia, with particular emphasis on the influence of Manning’s roughness coefficient on water conveyance and distribution efficiency. Field measurements were conducted at the head, middle and tail sections of main and secondary canals within a 250 ha command area using a 3-inch Parshall flume and a current meter. The results revealed clear deviation from the design conditions, with conveyance losses ranging from 2.55 to 34.9 L/s and main canal efficiency of 86.1
Springs are essential water sources in the Indian Himalayan region, particularly in rural and mountainous areas where they often serve as the primary water supply. However, increasing anthropogenic pressures and climate change have led to the depletion and drying up of many springs. This study aims to develop effective intervention strategies for spring restoration and sustainable management through geospatial analysis and hydrogeological mapping in the Upper Kosi River Basin, Uttarakhand. The study delineated groundwater potential zones by integrating eight key parameters: lineament density, lithology geomorphology, land use/land cover, rainfall, drainage density, slope, and soil type. These parameters were selected based on prior studies to reflect the major hydrogeological controls of the Himalayan terrain. The analytic hierarchy process was used to assign weights to each parameter based on their relative importance in influencing groundwater potential. The resulting map identified five groundwater potential classes: very good (12.8
Droughts remain major global challenges. In 2015/2016 the Tigray region (northern Ethiopia) was hit by the worst drought in 50 years. The region has been implementing various climate change adaptation practices for four decades at scale, including: soil and water conservation (SWC), small to medium size dams (SMSD), small-scale water harvesting (SSWH) (check-dams, check-dam ponds, ponds, etc.), and groundwater development. This study assessed water level and yield dynamics and resilience of groundwater systems to effects of droughts. We carried out a regional assessment of Tigray and a detailed study on 17 representative watersheds for four years (2015–2018) that involved: (i) evaluation of the implemented technologies and approaches, (ii) geohydrological characterization, (iii) monitoring groundwater wells (levels, yields) (n = 78) and spring discharge (n = 41), and (iv) participatory evaluations of the interventions. Groundwater wells and springs recharged by SWC, SSWH, dams and a natural lake were less affected by the 2015/2016 droughts and to any rainfall variability during the study period. Though the implemented groundwater recharge techniques/approaches were not designed systematically, they have created drought resilient groundwater systems. Key considerations for systematic recharge include: available excess runoff; appropriate recharge structures/technologies; suitable geohydrology for storage; upstream-downstream linkages and effects; and climate change. The evidence from northern Ethiopia shows the potential of nature-based solutions to create drought resilient groundwater systems through measures that enhance recharge. This study has important implications for future sustainable water and land management, and climate change adaptation practices in similar environments.
Floods are among the most devastating natural hazards, causing significant damage to communities, infrastructure, and local economies. This study integrates hydraulic modelling with geographic information systems and remote sensing techniques to simulate flood dynamics and assess housing exposure in the Vu Gia-Thu Bon River Basin, Quang Nam Province, Vietnam. The major historical 2020 flood event was analyzed using the MIKE FLOOD model to evaluate flood depth, duration, and velocity. Input data included topographic maps, river cross-sections, meteorological and hydrological records, and field-verified flood traces. Building footprints were extracted from high-resolution satellite imagery, and residential zones were mapped using recent land-use datasets. Flood inundation maps were overlaid with housing data to quantify exposure and identify spatial patterns of flood impact across key districts. The October 2020 flood event inundated an area of 7452.5 hectares and an estimated 800,994 flooded houses. In order of the districts affected by the 2020 flood event in terms of flood depth, duration, and velocity, as follows: Dien Ban > Dai Loc > Duy Xuyen > Hoi An. The findings highlight the importance of integrating modelling tools with geospatial analysis to support risk-informed decision-making and enhance disaster preparedness in flood-prone regions.
Water demand is rising globally due to population growth, rapid urbanization, climate change, and the need for economic development. The need for additional water storage is therefore increasing to meet these demands. Water storage, both natural and built infrastructure, offers a way to manage the availability of water resources. Properly planning and optimizing diverse water storage options for increasing water demand requires an assessment framework. We developed a framework for assessing water storage gaps under current and future scenarios. It is applied in an African setting in the Tana-Beles sub-basin of the Blue Nile basin, one of Ethiopia’s economic growth corridors, where irrigation and hydropower development are planned. The volume of usable water storage in Lake Tana, groundwater, and built reservoirs was estimated and compared with irrigation, energy, domestic, livestock, and industrial water demands for the current and future periods. Results showed that the current annual water storage gap is 613 MCM. The storage gap increases to 3663 MCM by 2040s, about five times higher than in the current period. Besides, spatial disparity exists between where most water storage is available and where the water demand occurs. Particularly, demands for irrigation, domestic use, and livestock are spread throughout the sub-basin while there is a strong reliance on surface water sources, which are located in the upstream part of the basin. Given that these sources are subject to spatial and temporal limitations, diversifying natural and built water storage sources is recommended to address the increasing gap between supply and demand.
Time Series Analysis (TSA) provides a statistical framework to assess the hydrodynamic behaviour of karst aquifers by analysing rainfall-discharge relationships. Using TSA as the primary analytical method, this study investigates two neighbouring tropical karst springs—Kalisirah and Jumbleng—in the South Gombong karst area, Central Java, Indonesia. Despite their close proximity (615 m), the springs exhibit markedly different discharge behaviours. Seven TSA approaches were applied, including auto-correlation, cross-correlation, spectral density, phase function, cross-amplitude, gain, and coherence functions. The results indicate that Kalisirah Spring shows a faster event response (shorter lag) and a shorter quick-flow release duration than Jumbleng Spring, consistent with a more developed karst structure. Both springs exhibit similar fissure-flow responses. Additional methods—Master Recession Curve (MRC) analysis, recession constant calculation, and tracer testing—were used to validate the TSA findings. These methods confirmed a higher level of karstification in the Kalisirah system, with shorter quick-flow release duration, higher advection and dispersion values, and a more complex conduit network. This multi-method framework highlights the importance of TSA in characterizing karst aquifer dynamics and emphasizes the need to integrate physical validation methods to support TSA results. This study also provides better insight into the hydrology of tropical karst as a regional and climatic setting that remains underrepresented in global karst studies, and offers a replicable approach for sustainable water resources management in similarly complex hydrogeological settings.
The increasing intensity and frequency of droughts under changing climatic conditions have raised serious concerns for sustainable water resource management. It is vital to understand the propagation of different types of drought and its characteristics. Meteorological and hydrological drought dynamics in Southern Odisha, India, were investigated using long-term (1987–2021) hydro-climatic data. Monthly data from four hydrometric stations namely Kesinga, Murthandi, Saradaput and Nabarangapurof streamflow, precipitation and maximum-minimum temperature were analysed to quantify drought frequency, duration, severity and to explore drought propagation mechanisms. Meteorological drought indices like Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were estimated to determine the dry and wet meteorological periods. Standardized Streamflow Index (SSFI)was also estimated to determine the hydrological drought. Correlation and cross over correlation analyses revealed strong linkages between the meteorological and hydrological droughts, at Kesinga and Nabarangapur stations with correlation coefficient (r > 0.8) at 12 and 24 months’ timescales. There is a frequent occurrence of mild hydrological drought in longer timescale at all the four stations. An exponential relationship between meteorological and hydrological drought was observed in terms of duration and magnitude. The most notable events are SPI-12 (42 months, severity 52.24), SPEI-12 (54 months, severity 66.04), and SSFI-12 (65 months, severity 74.6). A broader understanding of drought characteristics can be attained by incorporating numerous elements that impact and trigger the intensity of drought by using several indices that characterize diverse components related to hydrological cycle.
Saline and hypersaline shallow lakes in the central-western Pampean Plain (Argentina) develop under sub-humid climate conditions, where potential evapotranspiration exceeds precipitation. Although climate sets a common regional framework, the hydrogeomorphological context—defined by lithology, geomorphology, and topography—controls the geohydrological configuration of each system, conditioning the dynamics of water fluxes and, ultimately, the development and functioning of the shallow lakes. This study analyzes two contrasting shallow lake systems: E. El Parque, located in an interdune depression within the Utracán-Argentino transversal valley, and Chasilauquen, situated in a depression carved into the elevated structural plain. Integration of geomorphological and lithological characterization, hydrogeological monitoring, and hydrochemical analysis reveals that each system operates under a distinct hydrogeomorphological configuration. In the transversal valley, dunes act as preferential recharge zones supplying low-salinity groundwater toward the interdune depression, where loessic layers underlying the sandy sediments limit vertical infiltration favoring water accumulation. Salinization is driven primarily by evaporation, and the topographically elevated position makes the system sensitive to water table fluctuations, resulting in a seasonally variable water body without significant evaporite precipitation. In the elevated structural plain, depressions function as persistent discharge zones receiving both groundwater and surface runoff. The lower topographic position ensures continuous water availability, and solute enrichment driven by evaporation and dissolution of evaporitic salts leads to hypersaline conditions with extensive evaporite precipitation. These findings demonstrate that even within a shared climatic setting, hydrogeomorphological controls produce fundamentally different shallow lake behaviors, underscoring the need for integrated approaches in the study and management of these environments.
A stable and reliable water supply is fundamental to sustainable regional development. Therefore, understanding the contribution of baseflow to water availability during low-flow periods is critically important. Most baseflow separation studies focus on large basins, resulting in a limited understanding of baseflow variability in geologically heterogeneous mountain sub-basins. Using the Nanmoku watershed as a case study, we examined major ions, 222Rn, and stable water isotopes (δ18O and δD) across sub-basins with contrasting geological settings. We used these tracers to elucidate stream-water chemistry and to evaluate tracer-based baseflow separation in small catchments. HCO₃−, Ca2⁺, and Mg2⁺ increased in summer, likely owing to enhanced biologically driven weathering, whereas NO₃− was influenced by flushing of soil water. These seasonal effects make these ions unsuitable as tracers for baseflow separation. In contrast, Cl− is the most broadly applicable tracer because it showed a consistent inverse relationship with discharge. Na+ may also be useful as a tracer in areas underlain by strata with low abundances of Na-bearing minerals. In sub-basins with low ion concentrations, Cl− is not suitable for baseflow separation; however, elevated 222Rn concentrations and reduced variability in δ18O and δD of stream water indicate a groundwater-dominated, baseflow-like contribution to streamflow. These findings offer a framework for selecting tracers and evaluating baseflow contributions in geologically complex hilly and mountainous catchments.
This study presents the hydrogeological and vegetational context of lowland springs -known in Italian as risorgive or fontanili- in a sector of the southern Po Plain near Turin (north-western Italy). Despite their important ecological role, these springs remain understudied, particularly regarding the effects of climate change and human activities. Not included in Italy’s environmental protection regulations and often poorly maintained, they require accurate identification and characterisation to support monitoring and management by local authorities. This study adopts a multidisciplinary approach, combining hydrogeological analysis with vegetation surveys, an integration rarely found in recent literature. Fontanili in the study area were mapped, and two field campaigns were conducted in summer and autumn 2022. A total of 92 springs was identified, of which only 26 were active during the study period due to prolonged drought. Hydrochemical and piezometric analyses of the shallow aquifer were performed, alongside vegetation surveys carried out at 28 springs in autumn 2022 and spring 2023. Hydrochemical data revealed a contrast between groundwater and surface water characteristics, with calcium bicarbonate prevailing in groundwater and calcium sulphate in surface water. Vegetation data indicated a loss of hygrophilous species linked to water scarcity, along with an increase in invasive alien species. The results highlight the vulnerability of these ecosystems and the urgent need for their conservation. The study aims to raise awareness, promote further research, and encourage local authorities to take concrete action for the protection of these unique lowland spring habitats.
The Bahi Swamp sub-basin, situated in the semi-arid region of central Tanzania, is facing increasing water scarcity due to factors such as climate change and population growth, posing significant threats to food security and community livelihoods. To address the challenge of water availability in the area, this study aims to assess community awareness and practices in sustainable water resource management, with a focus on water harvesting. Data were collected using a semi-structured questionnaire administered to 260 participants. The results show that 47
