Search Results (220)

Intensity–Frequency–Duration Curves (IDF curves) are a tool applied in hydraulic and hydrology engineering to design infrastructure for rainfall management. They express how precipitation, with a defined duration (D) and intensity (I), is frequent in a certain area. They are built from past recorded rainfall series, applying the extreme value statistics, and they are considered invariant in time. However, the current climate change projections are showing a detectable positive trend in temperatures, which, according to Clausius–Clapeyron, is expected to intensify extreme precipitation (higher temperatures bring more water vapour available for precipitation). According to the IPCC (Intergovernmental Panel on Climate Change) reports, rainfall events are projected to intensify their magnitude and frequency, becoming more extreme, especially across “climatic hot-spot” areas such as the Mediterranean basin. Therefore, a sensible modification of IDF curves is expected, posing some challenges for future hydraulic infrastructure design (i.e., sewage networks), which may experience damage and failure due to extreme intensification. In this paper, a methodology for reconstructing IDF curves by analysing the EURO-CORDEX climate model outputs is presented. The methodology consists of the analysis of climatic rainfall series (that cover a future period up to 2100) using GEV (Generalised Extreme Value) techniques. The future anomalies of rainfall height (H) and their return period (RP) have been evaluated and then compared to the currently adopted IDF curves. The study is applied in Lombardy (Italy), a region characterised by strong orographic precipitation gradients due to the influence of Alpine complex orography. The future anomalies of H evaluated in the study show an increase of 20–30 mm (2071–2100 ensemble median, RCP 8.5) in rainfall depth. Conversely, a significant reduction in the return period by 40–60% (i.e., the current 100-year event becomes a ≈40–60-year event by 2071–2100 under RCP 8.5) is reported, leading to an intensification of extreme events. The former have been considered to correct the currently adopted IDF curves, taking into account climate change drivers. A series of applications in the field of hydraulic infrastructure (a stormwater retention tank and a sewage pipe) have demonstrated how the influence of IDF curve modification may change their design. The latter have shown how future RP modification (i.e., reduction) of the design rainfall may lead to systematic under-design and increased flood risk if not addressed properly. Full article

This study investigates the propagation of climate model variability to coastal groundwater systems under the high-emission RCP8.5 scenario, focusing on the Almyros Basin in Greece. Using Med-CORDEX bias-corrected climate projections, an Integrated Modelling System (IMS) combines UTHBAL (surface hydrology) and MODFLOW (groundwater hydrology) to simulate future conditions, including precipitation, temperature, evapotranspiration, groundwater recharge, water balance, and seawater intrusion (as a quantity). The analysis quantifies both central tendencies and inter-model spread, revealing substantial declines in groundwater recharge and intensified seawater intrusion, while highlighting the uncertainty introduced by climate model projections. These findings provide critical insights for adaptive water resource management and planning in Mediterranean coastal aquifers under climate change. Full article

The validation of climate models is important for ensuring accurate climate variability over a given region. This study evaluates the performance of multiple global climate model simulations from the Coupled Model Intercomparison Project Phases 5 and 6 and the downscaled regional climate model simulations from the Coordinated Regional Climate Downscaling Experiment against gridded observational data from the Climatic Research Unit gridded data during the historic period 1981–2000. Spatial analysis using monthly bias maps and statistical metrics (i.e., correlation coefficient, standard deviation, and centred root-mean-squared error) were employed to assess the model outputs’ ability to reproduce monthly temperature and precipitation patterns over South Africa. The results indicate an improvement in CMIP6 and CORDEX model simulation outputs compared to their CMIP5 predecessors, with reduced biases and enhanced correlation. The study underscores the importance of model selection for regional climate analysis and highlights a need for further model development to capture complex physical processes. Full article

This study investigates the sensitivity of an urban parameterization scheme of the Weather Research and Forecasting model (WRF). The model sensitivity is tested during the period April–May 2020 over the greater Paris region. The parent domain covers Europe with a 12 km horizontal resolution, with a nested one covering the greater Paris region with a 3 km horizontal resolution. A multi-layer urban scheme called Building Effect Parameterization coupled with the Building Energy Model (BEP-BEM) was applied in two simulations: (1) BEP-BEM Paris, with urban options tailored for the Paris region, which were derived from Earth Observation data, and (2) BEP-BEM Europe, which uses an updated urban parameter table with an estimated average profile for European cities. These two simulations were compared with observations and a WRF simulation using a simple urban parameterization (BULK approach). BULK and multi-layer urban scheme experiments present a similar general error for April, underestimating temperature, while the BEP-BEM runs overestimate temperature for May. The simulation with the advanced tailored urban parameterization over Paris appears to have the best overall performance in this 2-month period. Full article

The temperature-based indicators heating and cooling degree days, are frequently utilized to quantitatively link indoor energy demand and outdoor thermal conditions, especially in the context of climate change. We present a comprehensive study of the heating and cooling degree-days and the degree-days categories for the near past (1976–2005), and the AR5 RCP4.5 and RCP8.5 scenario-driven future (2066–2095) over Southeast Europe based on an elaborated methodology and performed using a 19 combinations of driving global and regional climate models from EURO-CORDEX with horizontal resolution of 0.11°. Alongside the explicit focus of the degree-days categories and the finer grid resolution, the study benefits substantially from the consideration of the monthly, rather than annual, time scale, which allows the assessment of the intra-annual variations of all analyzed parameters. We provide evidences that the EURO-CORDEX ensemble is capable of simulating the spatiotemporal patterns of the degree-days and degree-day categories for the near past period. Generally, we demonstrate also a steady growth in cooling and a decrease in heating degree-days, where the change of the former is larger in relative terms. Additionally, we show an overall shift toward warmer degree-day categories as well as prolongation of the cooling season and shortening of the heating season. As a whole, the magnitude of the projected long-term changes is significantly stronger for the ’pessimistic’ scenario RCP8.5 than the ’realistic’ scenario RCP4.5. These outcomes are consistent with the well-documented general temperature trend in the gradually warming climate of Southeast Europe. The patterns of the projected long-term changes, however, exhibit essential heterogeneity, both in time and space, as well as among the analyzed parameters. This finding is manifested, in particular, in the coexistence of opposite tendencies for some degree-day categories over neighboring parts of the domain and non-negligible month-to-month variations. Most importantly, the present study unequivocally affirms the significance of the anticipated long-term changes of the considered parameters over Southeast Europe in the RCP scenario-driven future with all subsequent and far-reaching effects on the heating, cooling, and ventilation industry. Full article

Anthropogenic alterations of the land surface through activities such as agriculture, forestry and urban development represent important human-induced forcings on the Earth’s climate system. This study, conducted in the framework of the UpClim project, employs the non-hydrostatic WRF-ARW v4.5.1 model forced by ERA5 reanalysis data to assess the impact of land use changes (LUCs) on the European climate. The study aims to quantify the effects of LUCs over the EURO-CORDEX domain at 0.11° resolution during 1980–1985 by comparing simulations with transient land use forcing against a control run with static land use. Full article

Tourism in Greece is directly influenced by bioclimatic conditions, with thermal comfort being a key determinant of destination suitability. This study quantifies projected changes in outdoor thermal stress across 25 representative Greek tourism locations using the Physiologically Equivalent Temperature (PET) index. The analysis employs daily outputs from four EURO-CORDEX regional climate model simulations at ~11 km spatial resolution, covering the period 1970–2100 under three Representative Concentration Pathways (RCP2.6, RCP4.5, RCP8.5). Predominant PET classes were derived for a reference period (1971–2000) and two future horizons (2031–2060, 2071–2100) to evaluate the spatiotemporal evolution of thermal comfort. The results reveal a consistent upward shift toward higher PET classes, indicating intensifying thermal stress. During the baseline, moderate to strong heat stress (29–35 °C) dominated summer months, with cold stress (<8 °C) restricted to northern and high-altitude stations. By mid-century, even under RCP2.6, summer PET values increasingly exceed 35–41 °C, while RCP8.5 simulations show the first occurrence of extreme PET (>41 °C). By late century, RCP2.6 stabilizes heat stress, whereas RCP4.5 exhibits widespread dominance of strong stress classes and elimination of cold stress. Under RCP8.5, July–August are uniformly categorized as extreme (>41 °C) across nearly all stations, and transitional months shift toward high stress, leading to a homogenization of summer conditions. These findings underscore the high sensitivity of Greek tourism destinations to climate change, highlighting both the critical benefits of global emissions mitigation and the urgent need for locally tailored adaptation strategies. Full article

The Athabasca River Basin (ARB) is the location of the Canadian oil sands industry and 70.8% of global estimated bitumen deposits. The Athabasca River is the water source for highly water-intensive bitumen processing. Our objective is to project ARB temperature, precipitation, total runoff, climate moisture index (CMI), and standardized precipitation evapotranspiration index (SPEI) for 2011–2100 using the superior modelling skill of seven regional climate models (RCMs) from Coordinated Regional Climate Downscaling Experiment (CORDEX). These projections show an average 6 °C annual temperature increase for 2071–2100 under RCP 8.5 relative to 1971–2000. Resulting increases in evapotranspiration may be partially offset by an average 0.3 mm/day annual precipitation increase. The projected precipitation increases are in the winter, spring, and autumn, with declines in summer. CORDEX RCMs project a slight increase (0.04 mm/day) in annual averaged runoff, with a shift to an earlier springtime melt pulse. However, these are countered by projected declines in summer and early autumn runoff. There will be significant decreases in annual and summertime CMI and annual SPEI. We conclude that there will be increasingly stressed ARB water availability, particularly in summer, doubtless resulting in repercussions on ARB industrial activities with their extensive water allocations and withdrawals. Full article

Changes in agricultural drought frequency (DF), duration (DD) and severity (DS) in Greece are investigated based on 11 high-resolution EURO-CORDEX regional climate model simulations covering the period 1971–2100 under three different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) with the use of the SPI and SPEI. Increases in DF, DD and DS are more prominent in the 2071–2100 period under RCP8.5. Central and southern Greece, the Aegean islands and Crete experience the largest increases under RCP4.5 and RCP8.5. Under RCP2.6, changes in DD and DS are less pronounced, especially over northern Greece. Full article

Here, we assess the projected changes in photovoltaic power generation potential (PVpot) in Greece for the 21st century. Our analysis is based on an ensemble of high-resolution Regional Climate Model (RCM) simulations from the EURO-CORDEX initiative following three different Representative Concentration Pathways (RCPs), namely, RCP2.6 (strong mitigation), RCP4.5 (moderate mitigation), and RCP8.5 (no further mitigation). The spatial patterns of the PVpot changes in the near future (2021–2050) and at the end of the century (2071–2100) relative to the 1971–2000 baseline period are presented along with the corresponding statistical robustness. In addition, we analyze time series of the projected PVpot changes. Finally, we isolate the effects of specific climatic variables on the projected PVpot changes and discuss the importance of PV energy production in Greece. Full article

The future climate is anticipated to affect economic activities, the unique natural and forest ecosystems, agriculture, buildings, and communities in the region of the Troodos Mountains in Cyprus. The current study, as part of the European project Regions4Climate (R4C), aimed to develop a sustainable tourism model for this specific region to ensure the climate resilience of the Troodos communities while preserving its traditional products and ecosystems for future generations. Tangible key risk climate indicators were calculated using the CORDEX climate surface datasets to estimate the spatial changes under two climate scenarios, RCP4.5 and RCP8.5. The climate indicators were specifically selected to identify several known regional hazards, such as drought, heatwaves, forest fires, etc., that are linked to impacts on socio-economic activities like tourism, ecosystems, agriculture, energy, and water resources. Full article

The deterioration of porous building materials in archeological monuments is often intensified by slow and cumulative compound climate events, including salt crystallization cycles. This research examines the spatial patterns of these damaging events across Greece using high-resolution climate simulations derived from ERA-Interim and ERA5 Reanalysis datasets, as well as EURO-CORDEX models. By analyzing both past conditions (1980–2004) and projected future scenarios (2025–2049) under RCP4.5 and RCP8.5, the study identifies regions at heightened risk and explores how climate change influences the occurrence and possibly alters the aggressiveness of such events. By mapping the total frequency of these events and their anticipated changes under future climate conditions, this study contributes to developing a climatology of compound events that affect porous building materials of cultural heritage importance. Full article

Heatwaves are among the deadliest climate-related hazards, with their intensity and frequency projected to rise. This study develops a machine learning model to predict heatwave-related mortality in Greece under RCP4.5 and RCP8.5 scenarios. Historical mortality and climate data (2015–2024) were combined with future projections (2025–2050) from CORDEX models. Feature engineering included lagged heatwave indicators, seasonal effects, and age group interactions. An optimized XGBoost model revealed increasing mortality trends, especially under RCP8.5 after 2039. These findings highlight the growing public health threat posed by extreme heat and offer a predictive framework for climate adaptation and policy planning. Full article

This study assesses the impact of climate change and glacier retreat on river runoff in the high-altitude Terek River Basin using the physically based ECOMAG hydrological model. Sensitivity experiments examined the influence of glaciation, precipitation, and air temperature on runoff variability. Results indicate that glacier retreat primarily affects streamflow in upper reaches during peak melt (July–October), while precipitation changes influence both annual runoff and peak flows (May–October). Rising temperatures shift snowmelt to earlier periods, increasing runoff in spring and autumn but reducing it in summer. The increase in autumn runoff is also due to the shift between solid and liquid precipitation, as warmer temperatures cause more precipitation to fall as rain, rather than snow. Scenario-based modeling incorporated projected glacier area changes (GloGEMflow-DD) and regional climate data (CORDEX) under RCP2.6 and RCP8.5 scenarios. Simulated runoff changes by the end of the 21st century (2070–2099) compared to the historical period (1977–2005) ranged from −2% to +5% under RCP2.6 and from −8% to +14% under RCP8.5. Analysis of runoff components (snowmelt, rainfall, and glacier melt) revealed that changes in river flow are largely determined by the elevation of snow and glacier accumulation zones and the rate of their degradation. The projected trends are consistent with current observations and emphasize the need for adaptive water resource management and risk mitigation strategies in glacier-fed catchments under climate change. Full article

This study investigates the impact of climate change on the Mudurnu Stream Basin in northwest Türkiye by analyzing climate parameters in the Mediterranean region. Historical data from EC-Earth2, HadGEM2-ES, and MPI-ESM-MR GCMs from the CMIP5 Euro-CORDEX archive were assessed, and future precipitation and temperature data were derived using five statistical bias correction methods for the selected EC-Earth2 model under RCP4.5 and RCP8.5 scenarios. The SWAT model was employed to simulate future runoff amounts for the Mudurnu Stream Basin. The findings reveal notable changes in precipitation and temperature. The annual and seasonal variations of total precipitation and average, maximum, and minimum temperatures for the RCP4.5 and RCP8.5 scenarios in the Sakarya and Mudurnu regions were analyzed and determined. The projections for future river flow indicate a significant increase in precipitation during the rainy seasons. The Mudurnu Stream mainstem will experience an increase in flow of between 70 and 140% under RCP4.5 and between 80 and 160% under RCP8.5. In the Dinsiz Stream tributary, a 32–55% increase is observed for the spring and summer months. In this context, the rainfall and runoff projections required for the estimation of potential drought and flood risks in the near and distant future were calculated. Full article