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.
