Search Results (831)

This study presents an integrated stochastic framework for assessing and forecasting drought dynamics in the western Bhagirathi–Hooghly River Basin, encompassing the districts of Bankura, Birbhum, Burdwan, Medinipur, and Purulia. Employing multiple probabilistic and statistical techniques, including the gamma-based standardized precipitation index (SPI), effective drought index (EDI), rainfall anomaly index (RAI), and the auto-regressive integrated moving average (ARIMA) model, the research quantifies spatio-temporal variability and projects drought risk under non-stationary climatic conditions. The analysis of century-long rainfall records (1905–2023), coupled with LANDSAT-derived vegetation and moisture indices, reveals escalating drought frequency and severity, particularly in Purulia, where recurrent droughts occur at roughly four-year intervals. Stochastic evaluation of rainfall anomalies and SPI distributions indicates significant inter-annual variability and complex temporal dependencies across all districts. ARIMA-based forecasts (2025–2045) suggest persistent negative SPI trends, with Bankura and Purulia exhibiting heightened drought probability and reduced predictability at longer timescales. The integration of remote sensing and time-series modelling enhances the robustness of drought prediction by combining climatic stochasticity with land-surface responses. The findings demonstrate that a hybrid stochastic modelling approach effectively captures uncertainty in drought evolution and supports climate-resilient water resource management. This research contributes a novel, region-specific stochastic framework that advances risk-based drought assessment, aligning with the broader goal of developing adaptive and probabilistic environmental management strategies under changing climatic regimes. Full article

The ramifications of climate change, which are projected to lead to increased drought, desertification, and water scarcity, are expected to have a significant impact on the agricultural sector of Türkiye, particularly in the Mediterranean coastal regions. This study presents an extensive evaluation of potential agricultural drought conditions in southwestern Türkiye, using a high-resolution, convection-permitting (0.025°) modeling approach. We employ a single, physically consistent model chain, dynamically downscaling the CMIP6 MPI-ESM-HR Earth System Model with the COSMO-CLM regional climate model at a convection-permitting (CP) resolution (0.025°) under IPCC Shared Socioeconomic Pathways SSP3-7.0, reflecting a high-emission scenario with regional socioeconomic challenges. Southwestern Türkiye, situated at the intersection of the Mediterranean and continental climates, hosts rare climatic and ecological conditions that sustain a highly productive and diverse agricultural system. This region forms the backbone of Türkiye’s agricultural economy but is increasingly vulnerable to climate variability and fluctuations that threaten its agricultural stability and resilience. Our study employs a novel approach that utilizes multivariate assessment of agricultural drought in the Mediterranean Region by integrating precipitation, soil moisture, and temperature variables from 2.5 km resolution climate simulations. Agricultural drought conditions were evaluated using the Standardized Precipitation Index (SPI), the Standardized Soil Moisture Index (SSI), and the Standardized Temperature Index (STI), derived by normalizing respective climate variables from climate simulations spanning from 1995 to 2014 for the historical period, from 2040 to 2049 and from 2070 to 2079 for future projections. CP climate simulations (CPCSs) exhibit a modest warm and dry bias during all seasons but slightly wetter conditions during summer when compared with station observations. Correlations between indices indicate that soil moisture variations in the future will become more sensitive to changes in temperature rather than precipitation. Results from this specific model chain reveal that the probability of compound events where precipitation and soil moisture deficits coincide with anomalously high temperatures will rise for all threshold levels under the SSP3-7.0 scenario towards the end of the century. For the most severe conditions (|Z| > 1.2), the compound likelihood increases to about 3%, highlighting the enhanced occurrence of rare events in a changing climate. These findings, conditional on the model and scenario used, provide a high-resolution, physically grounded perspective on the potential intensification of agricultural drought regimes. Full article

Drought remains one of the most damaging natural hazards to agricultural production and is projected to continue posing substantial risks to food security in the future, particularly in major rice-growing regions. Based on the RCP4.5 and RCP8.5 scenarios under CMIP5, this study used a process-based crop growth model to simulate the growth of rice in China in different future periods (short-term (2031–2050), medium-term (2051–2070), and long-term (2071–2090)). We fitted rice vulnerability curves to evaluate the rice drought risk quantitatively according to the simulated water stress (WS) and yield. The results showed that the drought hazard in major rice-growing areas in China (MRAC) were low in the middle and high in the north and south. The areas without rice yield loss will decline in the future, while the areas with a high yield loss will increase, especially in southwestern China and the middle and lower Yangtze Plain (MLYP). Owing to the markedly increased evaporative demand and the reduced moisture transport caused by a weakening East Asian summer monsoon, northeastern China will be a high-risk area in the future, with the expected yield loss rates in scenarios RCP4.5 and RCP8.5 being 39.75% and 45.5%, respectively. In addition, under the RCP8.5 scenario, the yield loss rate of different return periods in south China will exceed 80%. A significant gap between rice supply and demand affected by drought is expected in the short-term future. The gaps will be 67,770 kt and 78,110 kt under the RCP4.5-SSP2 and RCP8.5-SSP3 scenarios, respectively. The methodology developed in this paper can support the quantitative assessment of drought loss risk in different scenarios using crop growth models. In the context of the future expansion of Chinese grain demand, this study can serve as a reference to improve the capacity for regional drought risk prevention and ensure regional food security. Full article

Hydrological droughts represent a growing challenge for northern watersheds in Thailand, where climate change is projected to intensify seasonal water stress and destabilize agricultural productivity and water resource management. This study employed the Composite Hydrological Drought Index (CHDI) to evaluate the spatiotemporal characteristics of future droughts under representative concentration pathway (RCP) scenarios. The findings revealed a pronounced seasonal contrast: under RCP8.5, the CHDI values indicated more severe drought conditions during the dry season and greater flood potential during the wet season. Consequently, the region faces dual hydrological threats: prolonged water deficits and increased flood exposure within the same annual cycle. Drought persistence is expected to intensify, with maximum consecutive drought runs extending up to 10–11 months in future projections. The underlying mechanisms include increased actual evapotranspiration, which accelerates soil moisture depletion, enhanced rainfall variability, which drives the sequencing of floods and droughts, and catchment storage properties, which govern hydrological resilience. These interconnected processes alter the timing and clustering of drought events, concentrating hydrological stress during periods that are sensitive to agriculture. Overall, drought behavior in northern Thailand is projected to intensify in a spatially heterogeneous pattern, emphasizing the need for localized, integrated adaptation measures and flexible water management strategies to mitigate future risks of drought. Full article

Construction of new seawater reverse osmosis desalination (SWRO) plants in the state of California (USA) requires environmental permits containing rather strict conditions. The California Ocean Plan requires the use of subsurface intake systems (SSIs) unless they are deemed to be not feasible. The Governor of California requested that the State Water Resources Control Board (State Board) study the issue of accelerating the desalination plant permitting process and making it more efficient. The State Board formed an independent scientific Panel to study the issue of SSI feasibility and to submit a report. The Panel recommendations included the following: the feasibility assessment (FA) for SSIs should be streamlined for completion within a maximum of three years, and this requirement should be added to the Ocean Plan; applicants need to perform a financial feasibility study before pursuing SSI capacities exceeding 38,000 m³/d (10 MGD) for wells or 100,000 m³/d (25 MGD) for galleries because project financing may be denied for such larger capacity systems; the mitigation options for each site–SSI combination in the screening process should be addressed by both the project proponent and regulatory agencies as early as practicable in the overall permitting process; and the impacts of SSIs on local aquifers and associated wetland systems must be assessed during the analyses conducted during the FA and during post-construction monitoring. The Panel further concluded that the design and evaluation of SSI–site combinations are highly site-specific, involving technically complex issues, which require both the applicant and the reviewing state agencies to have the expertise to design and review the applications. Economic feasibility must consider cost to the consumer and the engineering risk that can preclude project financing. Projected capacities exceeding the above noted limits may not by financed due to risks of failure or could require government guarantees to lenders. The current permitting system in California is likely to preclude construction of large seawater desalination facilities that can provide another source of potable water for coastal communities in California during severe droughts. Without seawater desalination, the potable water supply in California would suffer a greater sustainability and resilience risk during future periods of extended drought. Full article

According to climate projections, the Pannonian region is expected to experience an increasing frequency of drought events. This trend affects not only agricultural areas but also natural grasslands. The Festuca wagneri species, selected for this study, is a dominant and well-adapted grass in dry natural habitats. A total of 54 Festuca wagneri individuals were examined across three soil types: sand, loam, and clay. In each soil type, 18 plants were assessed for drought tolerance. Water was applied at three dosage levels: 200, 300, and 400 mL. The experiment was conducted between 4 April and 18 July 2024, during which the total weight of the pots and the amount of drained water were measured regularly. All data processing and statistical analyses were performed in R version 4.3.2. A three-way factorial ANOVA was used to evaluate main and interaction effects. Model residuals were tested for normality (Shapiro–Wilk test) and homoscedasticity using diagnostic plots. The results showed that Festuca wagneri individuals tolerated even the lowest soil moisture levels induced by low water-holding capacity of the soil and low water input. This indicates that the species can be effectively used in grassland management and restoration under future climate change scenarios. The main differences were observed among soil types, highlighting the crucial importance of soil structure when establishing this species. Loam soils, already near optimal, respond best to moderate. Full article

Accurate prediction of meteorological drought is essential for climate adaptation and sustainable water management in arid regions. Using the Standardized Precipitation Evapotranspiration Index (SPEI) derived from 1962–2021 meteorological observations, this study analyzed multi-scale drought evolution in the Arid Area of Northwest China (AANC) and revealed a distinct shift from wetting to drying after the 1997 abrupt warming. Correlation analysis indicated that the rapid temperature rise significantly enhanced evapotranspiration, offsetting the humidification effect of precipitation. To improve predictive performance, a Stacking ensemble framework was developed by integrating Elastic Network, Random Forest, and Prophet + XGBoost models, with the outputs of the base learners serving as inputs to a meta-regression layer. Compared with single models (NSE ≤ 0.742), the integrated model achieved superior accuracy (NSE = 0.886, MAE = 0.236, RMSE = 0.214), and its residuals followed a near-normal distribution, indicating high robustness. Future projections for 2022–2035 show consistent declines in SPEI₁, SPEI₃, SPEI₆, SPEI₁₂, and SPEI₂₄, suggesting that the AANC will experience increasingly frequent and severe droughts as warming-induced evaporation continues to outweigh the humidification effect of precipitation. This integrated framework enhances drought predictability and provides theoretical support for climate risk assessment and adaptive water management in arid environments. Full article

Reforestation efforts, notably the massive Grain for Green Project (GFGP), have significantly greened China’s Loess Plateau (LP) but intensified regional water limitations. This study aims to systematically characterize the spatio-temporal dynamics and the critical legacy effects of moisture stress on eWUE to evaluate ecosystem sustainability under accelerated climate change. Using 2001–2020 MODIS GPP and ET data and the comprehensive Temperature–Vegetation–Precipitation Drought Index (TVPDI), we analyzed the trends, spatial patterns, and lagged correlations on the LP. We find the LP’s mean eWUE was 1.302 g C kg⁻¹ H₂O, exhibiting a robust increasing trend of 0.001 g C kg⁻¹ H₂O a⁻¹ (p < 0.05), primarily driven by a faster increase in gross primary productivity (GPP) than evapotranspiration (ET). Spatially, areas with significant increases in eWUE concentrated in the afforested south and central LP. Concurrently, the region experienced a mild drought state (mean TVPDI: 0.557) with a concerning drying trend of 0.003 yeyr⁻¹, highlighting persistent water stress. Crucially, eWUE exhibited high and spatially divergent sensitivity to drought. A striking 69.64% of the region showed a positive correlation between eWUE and the TVPDI, suggesting that vegetation may adjust its physiological functions to adapt to drought. However, this correlation varied across vegetation types, with grasslands showing the highest positive correlation (0.415) while woody vegetation types largely showed a negative correlation. Most importantly, our analysis reveals a pronounced drought legacy effect: the correlation between eWUE and drought in the previous two years was stronger than in the current year, indicating multi-year cumulative moisture deficit rather than immediate climatic forcing (precipitation and temperature). These findings offer a critical scientific foundation for optimizing water resource management and developing resilient “right tree, right place” ecological restoration strategies on the LP, mitigating the ecological risks posed by prolonged drought legacy. Full article

The projected climate change in Slovakia is expected to have a significant impact on temperature and moisture conditions in agricultural production, as well as on phenological patterns and soil properties. These alterations have the potential to diminish crop yields in regions experiencing summer heat, augment soil evaporation, and elevate the probability of drought. The objective of this study was to evaluate and revise the spatial extent of vegetation zones and agricultural land. A detailed analysis of the past 30 years revealed that the growing season has become both earlier in the year and later in the year in terms of its onset and cessation. Projections indicate that, by 2091–2100, the great growing season (GGS) will be 25–30 days longer and the main growing season (MGS) 20 days longer than at present. The results indicate that the extended growing seasons will encompass larger areas and gradually shift to higher altitudes. At present, the 220–240-day category of the GGS spatial domain is dominant (1.7–2.3 million hectares), while durations of the GGS exceeding 260 days, which were absent in the 1971–1980 period, are expected to increase the area of the growing season by approximately 55,000 hectares by 2100. For the MGS, the 160–190-day category remains prevalent (approximately 2.5 million hectares), with only moderate future increases of up to 220 days being expected. It is anticipated that extended durations will remain constrained, encompassing less than 50,000 hectares. Full article

Optimizing field cropping practices to improve nitrogen use efficiency is imperative to promote intensive and sustainable wheat production. As a cultivation method commonly adopted in arid and semi-arid regions globally, the ridge–furrow mulching system (RFMS) is capable of efficiently harvesting rainfall, reduce evaporation losses, enhancing soil moisture levels in the root zone, and boosting crop productivity. However, the combined effects of varying ridge–furrow ratios (RD), ridge heights (RH), and nitrogen application rates (RN) on nitrogen fertilizer bias productivity (PFPN) under the influence of climatic conditions, soil types, and field management practices remain poorly understood due to a lack of systematic evaluation. This study conducted a meta-analysis of 462 comparative datasets from 98 research projects to reveal the interactive effects of RFMS and nitrogen fertilizer across climatic gradients. The results showed that RH, RD, and RN increased by 23.78%, 22.37%, and 23.07% respectively (p < 0.05), with the most significant enhancement of PFPN being demonstrated by RH. The most significant improvement in PFPN was observed when RD = 1:1, R < 10 cm, and RN > 200 kg∙hm⁻², with PFPN increasing by 27.7%, 29.50%, and 29.32% respectively (p < 0.05). Climatic and soil physico-chemical factors and field management practices are the key factors influencing the RFMS. When average annual evapotranspiration (AE) < 1000, RN > 200 has the best effect on nitrogen utilization efficiency, while under the condition of AE > 1500, RN < 100 is more effective. In terms of mulching strategy, full mulching of ridges and furrows is recommended in areas with severe drought and low temperatures, while mulching only ridges or furrows is more appropriate in areas with relatively mild climate. The present study provides a scientific basis for the optimal design of ridge–furrow mulching configuration and nitrogen application level. This is achieved by considering climatic conditions, soil fertility, and field management in agro-ecosystems in arid and semi-arid areas. Full article

This study aims to forecast the combined impacts of drought and flood in the future using an integrated framework. This framework integrates U-Net++, quantile mapping (QM), Copula models, and ISIMIP3b gridded large-scale discharge data (1985–2014, 2021–2050, and 2071–2100). Copula models analyze compound effects in four dimensions to determine return periods for droughts and floods. The standalone U-Net++ and its integration with multiple linear regression, multiple nonlinear regression, M5 model tree, multivariate adaptive regression splines, and QM downscaled ISIMIP3b model river flows. U-Net++QM outperformed other models, with a 58% lower RRMSE. Ensemble GCMs showed less uncertainty than other models in river flow downscaling. For the Ensemble model, the highest drought severity was −300, the maximum duration was 300 months, flood peak flow reached 12,000 m³/s, and intervals lasted up to 22 months. Moreover, the return periods of compound events for this model ranged from 50 to 3000 years. Future river flow projections, using the Ensemble model and emission scenarios (SSP126, SSP370, and SSP585), showed increased vulnerability in 2071 and 2025 versus the observed period. Introducing an integrated framework serves as a management tool for addressing extreme combined phenomena under climate change. Full article

As climate change increases the frequency and unpredictability of natural hazards, adapting critical infrastructure is crucial for long-term resilience. Among these hazards, embankment fires pose a growing threat to railway systems, particularly under rising temperatures and prolonged drought conditions. As part of the Horizon Europe project NATURE-DEMO, this study helps identify fire-prone rail segments and explore nature-based solutions, such as vegetation barriers, that can reduce ignition risk and enhance infrastructure resilience. In a case study, we analysed the risk of embankment fires for a section of the German railway network in detail. Based on an embankment-fire hazard indication map available for the entire German railway network, five hotspots within the study area were identified. Embankments with high fire susceptibility occur in both rural and urban areas, covering 1.1% of the study area. On the basis of published research on technical and nature-based solutions for reducing embankment fire susceptibility, we derived site-specific recommendations for the appropriate implementation of mitigation measures. Full article

The intensity of wildfires is projected to increase with the rising frequency of droughts due to climate change. Management practices following forest fires must include restoring the appropriate species composition. This study was performed within the wider context of the regeneration of soil properties, including the stock and soil organic matter (SOM) content, at the largest forest fire site in Poland (more than 9000 ha) in the Rudziniec Forest District, Upper Silesia. Research plots were established on sandy soils (Podzols and Arenosols) in pure stands of Scots pine (Pinus sylvestris L.), common birch (Betula pendula Roth), and black alder (Alnus glutinosa (L.) Gaertn.). The organic and mineral soil horizons were sampled from each research plot and control plots unaffected by the fire. The trees’ foliage was also sampled to determine the nutrient supply. Basic soil properties were determined, including the texture, pH, bulk density, organic carbon (C), macronutrient contents, soil microbial biomass, and labile C and nitrogen (N) fractions. We found that, 30 years after the fire, the post-fire soils had similar SOC stocks (34.80 Mg ha⁻¹) to the control plots (31.72 Mg ha⁻¹); however, they differed in their stocks of labile C and N fractions. The post-fire soils had a less stable C pool due to a higher stock of the fraction associated with particulate organic matter. In contrast, the N pool was more stable in the post-fire soils than in the control soils due to a lower contribution of the most labile fractions. The soils under Scots pine had the least stable SOM, which may have influenced the intensification of the podzolization process, whereas the highest biomass of soil microorganisms was observed under common birch. The soils under black alder had the highest acidity and lowest phosphorus (P) content. The C:N:P ratios in the post-fire soils and tree foliage indicated that P may have been the limiting factor in alder growth, and N for pine and birch. Our findings indicate that tree species composition is an important factor in the recovery of post-fire soil properties. However, the introduction of pure black alder stands to post-fire soils with low moisture and P availability showed little effectiveness in restoring the SOM content and N pool. Full article

Understanding the demographic mechanisms underlying the decline of endangered tree species is essential for developing effective conservation strategies. This study aimed to quantify the population trajectory and its demographic drivers in the Korean fir (Abies koreana), a subalpine conifer endemic to South Korea and listed as endangered by the IUCN, using a Bayesian Integral Projection Model (IPM). Based on eight years of field monitoring of survival, growth, and recruitment, the Bayesian IPM estimated the population growth rate (λ_s) and quantified its uncertainty under interannual environmental variation. The results indicated that interannual variation in drought, represented by the Standardized Precipitation–Evapotranspiration Index (SPEI), was a key driver of demographic changes. The mean population growth rate (λ = 0.983) suggests a slow decline, primarily driven by high mortality among intermediate-sized individuals, which are vital for maintaining population stability. In contrast, the growth of small to medium trees showed a weak but positive elasticity, implying that management actions targeting these size classes could benefit population persistence. Accordingly, effective conservation of A. koreana should focus on mitigating drought stress through reducing competition and improving soil moisture and structure. Full article

Climate change has exacerbated the occurrence of complex extreme hydrological events in high-latitude cold regions, among which drought–flood abrupt events (DFAAEs) threaten food and water security, and accurately predicting their future evolution remains a key challenge. This study used the Community Water Model (CWatM) hydrological model, combined with five CMIP6 climate models, to simulate runoff datasets for historical periods (1985–2014) and future shared socioeconomic pathways (SSPs: SSP126, SSP370, SSP585: 2015–2100). We calculated the DFAA index (DFAAI), analyzed the spatiotemporal distribution patterns and predicted future trends of DFAAEs in the Heilongjiang River Basin, and explored their climatic driving mechanisms. The main conclusions are as follows: (1) Under SSPs, precipitation and evaporation increase from northwest to southeast, and temperature increases from north to south; hotspots expand inland. By 2100, annual precipitation will reach 655, 700, and 720 mm; mean air temperature will rise by 3, 6, and 7 °C; and annual evapotranspiration will reach 460, 515, and 521 mm. (2) Relative to the historical period, DFAAEs increase from 5.9 to 6.6, 7.1, and 7.5 events per year (SSP126/370/585). Coverage rises from 10.6% to 12.7%, 17.1%, and 19.0%, while mean intensity remains 1.8–2.0. Across both the historical period and SSPs, the shares of light (69–74%), moderate (20–24%), and severe (6–8%) events are stable. (3) Principal Component 1 (PC1,62.9%) reflects a precipitation-dominated wetting mode with synchronous increases in evapotranspiration and is the primary driver of DFAAI variability. PC2 (20.3%) captures an energy-related mode governed mainly by evapotranspiration and indirectly modulated by air temperature, providing a secondary contribution. These results clarify DFAA mechanisms and inform water-resources security planning in the Heilongjiang River Basin. Full article