Search Results (72)

Stratospheric Aerosol Injection (SAI) has been investigated as a climate intervention strategy to offset global warming, and regional impacts studies rely on simulations from the Geoengineering Large Ensemble (GLENS). The probabilistic behavior of the GLENS ensemble has not been systematically characterized for Southeast Asia. Because GLENS is a counterfactual experiment combining the Representative Concentration Pathway 8.5 (RCP8.5) forcing with active SAI, comparison with observations cannot validate the SAI response itself. In the early protocol years, the SAI forcing is small, so the early window provides a diagnostic of statistical consistency between the ensemble and the observed climate and of ensemble spread reliability. We compare the 21-member GLENS ensemble for 2020–2025 with ERA5 for daily precipitation and mean and maximum temperature using empirical coverage of the 95% prediction interval, rank histograms with the Jolliffe–Primo decomposition, the Continuous Ranked Probability Score, and the Brier Score for rainfall occurrence. Coverage is well below nominal for all variables, and rank histograms show pronounced U-shapes dominated by the dispersion error component, indicating systematic underdispersion. Because the underlying mechanisms are properties of the ensemble system rather than of the SAI forcing, this underdispersion is expected to persist in the future record, motivating statistical post-processing of GLENS before its use in SAI impact assessments. Full article

Rainfall-induced shallow loess landslides pose a significant threat to human life and property. Early warning and risk assessment of these landslides are critical prerequisites for engineering control and disaster loss reduction. The Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model (TRIGRS)-Three-dimensional Slope Stability Analysis Tool (Scoops 3D) joint model can overcome the shortcomings of using a single TRIGRS model for hydrological analysis and a single Scoops 3D model for slope stability analysis. Landslide risk assessment based on expected economic loss, on the other hand, can overcome the issue of maintaining the risk level edge and sorting at the same level. In this paper, the TRIGRS model’s head pressures were put into the Scoops 3D model, with the southeast of Fangta, a town in Shaanxi province, China, as the study area. The relationship between the slope gradient and the number of grids in each stable grade was certified. The rainfall thresholds for landslides, based on both rainfall intensity and rainfall duration, were obtained by rerunning the TRIGRS-Scoops 3D joint model. The landslide range and land uses of each dangerous slope were determined by maximum likelihood classification, and then the expected economic loss was calculated. To verify the reliability of the TRIGRS-Scoops 3D joint model, the identified dangerous slopes were compared with the results from landslide susceptibility mapping. The results show that the unstable grids are concentrated within a slope gradient of 30° to 35°, and the landslide early warning levels are divided into Tier 3, Tier 2, and Tier 1 Warnings. The occurrence of shallow loess landslides is affected by both rainfall intensity and rainfall duration, and the combined effect should be considered in early warning. The distribution of both extreme susceptible grids and high susceptible grids across all 23 dangerous slopes demonstrates the reasonableness of the TRIGRS-Scoops 3D joint model. The landslide susceptible probability within some dangerous slopes exhibits spatial variability. The mapping relationship between the slope gradient and loess landslides is extremely complex. This paper can provide a theoretical basis for the early warning and risk management for rainfall-induced shallow loess landslides; the proposed method is also applicable to other regions with similar geological and meteorological conditions. 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

Rainfall-induced cut-slope failures are one of the main causes of traffic disruptions in road networks, consuming 30–50% of annual road maintenance budgets. Therefore, it is crucial to analyze how traffic disruptions, resulting from cut-slope failures, impact the overall operation of road networks. In addition, as climate change alters the precipitation patterns, the frequency of these phenomena is expected to increase. For these reasons, it is essential to develop a methodology, from a risk perspective, to understand and assess how cut-slope failures impact the normal operation of road networks. This article introduces a methodology to assess the risk of traffic disruption caused by rainfall-induced cut-slope failure, in terms of Origin–Destination travel time increases. The methodology comprises three stages: (1) modeling the rainfall hazard, (2) estimating the road network’s vulnerability to slope instability, and (3) quantifying risk through resulting travel time increases. A case study was performed on a road network highly vulnerable to cut-slope failure in the Biobío Region of southern Chile. The analysis using the GIS-based software revealed that rainfalls lasting more than 12 h increase average travel times by 20%, with maximum increases of about 40% for 24 h rainfalls, affecting travel between the main cities in the Biobio region and the Concepción metropolitan area. These results may be critical for decision-makers to identify highly exposed and vulnerable road sections in order to recommend effective mitigation strategies to reduce the risk of cut slope failures. Full article

The primary objective of this study is to assess the techno-economic feasibility of an innovative solar energy generation system with a rainwater collection feature to generate electrical energy and meet irrigation needs in agriculture. The proposed system is designed for an agricultural area (Gonyeli, North Cyprus) with high solar potential and limited rainfall. In the present study, global rainfall datasets are utilized to assess the potential of rainwater harvesting at the selected site. Due to the lack of the measured rainfall data at the selected site, the accuracy of rainfall of nine global reanalysis and analysis datasets (CHIRPS, CFSR, ERA5-LAND, ERA5, ERA5-AG, MERRA2, NOAA CPC CMORPH, NOAA CPC DAILY GLOBAL, and TerraClimate) are evaluated by using data from ground-based observations collected from the Meteorological Department located in Lefkoşa, Northern Cyprus from 1981 to 2023. The results demonstrate that ERA5 outperformed the other datasets, yielding a high R-squared value along with a low mean absolute error (MAE) and root mean square error (RMSE). Based on the best dataset, the potential of the rainwater harvesting system is estimated by analyzing the monthly and seasonal rainfall patterns utilizing 65 different probability distribution functions for the first time. Three goodness-of-fit tests are utilized to identify the best-fit probability distribution. The results show that the Johnson and Wakeby SB distributions outperform the other models in terms of fitting accuracy. Additionally, the results indicate that the rainwater harvesting system could supply between 31% and 38% of the building’s annual irrigation water demand (204 m³/year) based on average daily rainfall and between 285% and 346% based on maximum daily rainfall. Accordingly, the system might be able to collect a lot more water than is needed for irrigation, possibly producing an excess that could be stored for non-potable uses during periods of heavy rainfall. Furthermore, the techno-economic feasibility of the proposed system is evaluated using RETScreen software (version 9.1, 2023). The results show that household energy needs can be met by the proposed photovoltaic system, and the excess energy is transferred to the grid. Furthermore, the cash flow indicates that the investor can expect a return on investment from the proposed PV system within 2.4 years. Consequently, the findings demonstrate the significance of this system for promoting resource sustainability and climate change adaptation. Besides, the developed system can also help reduce environmental impact and enhance resilience in areas that rely on water and electricity. Full article

Dam breaks can lead to important economic and human losses. Design floods, which are useful to assess possible dam breaks, are usually estimated through statistical analysis of rainfall and streamflow observed data. However, such available samples are commonly limited and, consequently, high uncertainties are associated with the design flood estimates. In addition, climate change is expected to increase the frequency and magnitude of extreme rainfall and flood events in the future. Therefore, a methodology based on a stochastic rainfall generator is proposed to assess hydrological dam safety by considering climate change. We selected the Eugui Dam on the Arga river in the north of Spain as a case study that has a spillway operated by gates with a maximum capacity of 270 m³/s. The stochastic rainfall generator STORAGE is used to simulate long time series of 15-min precipitation in both current and future climate conditions. Precipitation projections of 12 climate modeling chains, related to the usual three 30-year periods (2011–2024; 2041–2070 and 2071–2100) and two emission scenarios of AR5 (RCP 4.5 and 8.5), are used to consider climate change in the STORAGE model. The simulated precipitation time series are transformed into runoff time series by using the continuous COSMO4SUB hydrological model, supplying continuous 15-min runoff time series as output. Annual maximum flood hydrographs are selected and considered as inflows to the Eugui Reservoir. The Volume Evaluation Method is applied to simulate the operation of the Eugui Dam spillway gates, obtaining maximum water levels in the reservoir and outflow hydrographs. The results show that the peak outflows at the Eugui Dam will be lower in the future. Therefore, maximum reservoir water levels will not increase in the future. The methodology proposed could allow practitioners and dam managers to check the hydrological dam safety requirements, accounting for climate change. Full article

In the actual context of climate change and increased multiannual climate variability, rainfall erosivity is one important topic linking geomorphological and climatological studies. Rainfall modeling is specific for a large part of the Romanian territory, and the estimation of rainfall erosivity is very important because it supports a better management of the arable land. The study is spatially focused on the extra-Carpathian region of Moldova, located in the northeastern part of Romania. Two rainfall erosivity indices were used: Fournier Index and Modified Fournier Index. To complete this analysis, we also used hourly data from two meteorological stations located over the most critical area of soil erosion in Romania (Cârja and Mădârjac). Our results reconfirm the extension of the critical season for soil erosion from May to July over the analyzed region, with its peak clearly defined during June. Based on the maximum hourly rainfall intensities, the synoptic aspects which led to the fall of significant amounts of precipitation in a short time interval were discussed. This analysis outlines the prevalent role of convective systems during summer, developed either within westerly flow or blocking conditions, seconded by the action of deep Mediterranean cyclones in late spring or early autumn. The results could be helpful in a very necessary attempt to develop and implement arable land management policies aiming to limit soil erosion in northeastern Romania, which is very necessary for the next decades when climate change is expected to increase this soil degradation process. Full article

In the recent decades, an ongoing increase in maximum temperature during summer has been observed in Poland, especially in the central-southern and southeastern areas. This raises the vulnerability of these regions not only to heat waves and drought but also to floods. The potential effect of compound heat waves and extreme rainfall events may be more serious than the effects of these events occurring separately. This research is the first attempt in Poland to investigate whether the presence of a heat wave increases the likelihood of extreme rainfall events, if so, by how much, and whether this changes with warming. For this purpose, we used daily maximum temperature values and 6 h precipitation datasets from 44 meteorological stations in Poland for the 1966–2024 period. It was proven that compound heat wave and extreme rainfall events occurred in Poland with spatially differentiated frequency. They occurred the least frequently on the coast and the most frequently in southwestern, southeastern, and northeastern Poland. The extreme rainfall occurred most often between noon and midnight on the last heat wave day. During these hours, the likelihood of extreme rainfall is, on average, 3.5 times higher than that expected according to climatology norms. With warming, the frequency of days with these compound events increases at the rate of 1.22 days per decade, and the frequency of compound events increases at a rate of 3.75 events per decade. Although a detailed analysis of the mechanisms responsible for such events is planned for further research, the preliminary study revealed that in most cases, the approach of a cold front with a mesoscale thundercloud system was responsible for heat wave termination with extreme rainfall. Since we cannot prevent the growing number of heat waves or heavy precipitation events that terminate the heat wave events in Poland, the adaptation strategy needs to be implemented to meet the sustainable development goals regarding climate actions. This refers primarily to urban planning, agriculture (agroecosystems), social health, and well-being. Full article

With its unique environment and strategic value, the near space (NS) has become the focus of global scientific and technological, military, and commercial fields. Aiming at the problem of communication interruption when the aircraft re-enters the atmosphere, to ensure the needs of communication, navigation, and telemetry, tracking, and command (TT&C), this paper proposes an overall integration of communication, navigation, and TT&C (ICNT) signals scheme based on the K/Ka frequency band. Firstly, the K/Ka frequency band is selected according to the ITU frequency division, high-speed communication requirements, advantages of space-based over-the-horizon relay, overcoming the blackout problem, and the development trend of high frequencies. Secondly, the influence of the physical characteristics of the NS on ICNT is analyzed through simulation. The results show that when the K/Ka signal is transmitted in the NS, the path loss changes significantly with the elevation angle. The bottom layer loss at an elevation angle of 90° is between 143.5 and 150.5 dB, and the top layer loss is between 157.5 and 164.4 dB; the maximum attenuation of the bottom layer and the top layer at an elevation angle of 0° is close to 180 dB and 187 dB, respectively. In terms of rainfall attenuation, when a 30 GHz signal passes through a 100 km rain area under moderate rain conditions, the horizontal and vertical polarization losses reach 225 dB and 185 dB, respectively, and the rainfall attenuation increases with the increase in frequency. For gas absorption, the loss of water vapor is higher than that of oxygen molecules; when a 30 GHz signal is transmitted for 100 km, the loss of water vapor is 17 dB, while that of oxygen is 2 dB. The loss of clouds and fog is relatively small, less than 1 dB. Increasing the frequency and the antenna elevation angle can reduce the atmospheric scintillation. In addition, factors such as the plasma sheath and multipath also affect the signal propagation. In terms of modulation technology, the constant envelope signal shows an advantage in spectral efficiency; the new integrated signal obtained by integrating communication, navigation, and TT&C signals into a single K/Ka frequency point has excellent characteristics in the simulation of power spectral density (PSD) and autocorrelation function (ACF), verifying the feasibility of the scheme. The proposed ICNT scheme is expected to provide an innovative solution example for the communication, navigation, and TT&C requirements of NS vehicles during the re-entry phase. Full article

Mountain regions are particularly sensitive and vulnerable to the impacts of climate change. Over the past three decades, mountain temperatures have risen significantly faster than those in lowland areas. The Hindu Kush–Karakoram–Himalaya region, often referred to as the “water tower of Asia”, is the largest freshwater source outside the polar regions. However, it is currently undergoing cryospheric degradation as a result of climatic change. In this study, the Normalized Difference Glacier Index (NDGI) was calculated using Landsat and Sentinel satellite images. The results revealed that glaciers in Chitral, located in the Eastern Hindu Kush Mountains of Pakistan, lost 816 km² (31%) of their total area between 1992 and 2022. On average, 27 km² of glacier area was lost annually, with recession accelerating between 1997 and 2002 and again after 2007. Satellite analyses also indicated a significant increase in both maximum (+7.3 °C) and minimum (+3.6 °C) land surface temperatures between 1992 and 2022. Climate data analyses using the Mann–Kendall test, Theil–Sen Slope method, and the Autoregressive Integrated Moving Average (ARIMA) model showed a clear increase in air temperatures from 1967 to 2022, particularly during the summer months (June, July, and August). This warming trend is expected to continue until at least 2042. Over the same period, annual precipitation decreased, primarily due to reduced snowfall in winter. However, rainfall may have slightly increased during the summer months, further accelerating glacial melting. Additionally, the snowmelt season began consistently earlier. While initial glacier melting may temporarily boost water resources, it also poses risks to communities and economies, particularly through more frequent and larger floods. Over time, the remaining smaller glaciers will contribute only a fraction of the former runoff, leading to potential water stress. As such, monitoring glaciers, climate change, and runoff patterns is critical for sustainable water management and strengthening resilience in the region. Full article

Soybeans are the most widely produced oilseed and the fifth most cultivated crop in the world. However, their growth and yield are significantly influenced by weather conditions. In Southern Brazil’s subtropical climate, farmers employ a double-cropping system, planting corn from late winter to early summer, followed by soybeans, which are sown after the corn harvest—typically in January—and harvested in autumn. This study argues that climate change has benefited late-sown soybeans in Rio Grande do Sul and will continue improving their growing conditions. The aim is to identify climate change’s past and future impacts on late-sowing soybean crop yields in this region. We evaluated the effects of climate on soybean yields using the HadGEM2-CC model (CMIP-5) for two scenarios (RCPs 4.5 and 8.5) and for two time periods (mid-and late-century). Additionally, the CSM-CERES-Maize model within DSSAT was also used to simulate corn yields under these climatic conditions. Our climatic analysis indicates an increase in rainfall and temperature, particularly in minimum temperatures, alongside significant rises in both minimum and maximum temperature extremes, and a reduction in frost days. Furthermore, higher atmospheric CO₂ levels are projected to enhance net photosynthesis, likely leading to increases in potential yield (Py) with rising CO₂ concentrations. Notably, the largest increases in achievable yield (Ay) are anticipated for early sowing dates under the mid- and late-century scenarios of RCP 4.5. Past climate changes have already improved the growth and yield potential of late-sown soybeans in Southern Brazil, a trend expected to continue as climate change further optimizes temperature and rainfall conditions. In conclusion, the late growing season for soybeans is predicted to be extended. Full article

Extreme high flows can have negative economic, social, and ecological effects and are expected to become more severe in many regions due to climate change. Knowledge of maximum flow regimes and estimation of extreme rainfall is important, especially in ungauged dry regions, for planning and infrastructure development. In this study, we propose a regional method for estimating extreme flow regimes and modeled extreme rainfall using the extreme value theory, with examples from the Gobi region of Mongolia. The first step is to apply the Generalized Extreme Value (GEV) theory for the maximum rainfall data using 44-year observational data covering the period 1978–2022. Then, estimated rainfall with a 100-year return period is used for the empirical equation of the maximum flood calculation. As a result, most stations’ maximum rainfall follows a Fréchet distribution and 100-year return period rainfall values that range between 27.8–130.6 mm. The local reference value in the 100-year return period rainfall is defined as 90 mm for the whole Gobi region. Our results show that extremely high rainfall in the Gobi region has changed from −7% to 16%, leading to higher flood events. These findings further provide evidence for the maximum rainfall for flood calculation, climate change impact assessment, water resource planning, and management studies. Full article

Global urbanization has led to the overexploitation and pollution of groundwater resources, restricting the sustainable construction and development of cities. Groundwater environmental carrying capacity (GW-ECC) refers to the maximum total amount of pollutants that can be accommodated by a given groundwater system within a certain time period and under specified environmental goals. To better understand the changes in GW-ECC in the context of rapid urbanization, this study built a model of the urban GW-ECC driven by multiple factors. Taking the urban area of Zhengzhou as an example, rainfall infiltration and riverside seepage within the urban groundwater system were calculated considering the change in the impervious area over the past 20 years. The Mann–Kendall rank test was used to evaluate the varying trends of the two factors in the urbanization process. Based on this, the change in the GW-ECC in the current year was calculated, and the changes under different regulatory schemes after 10 years was calculated and evaluated. The results showed that the model constructed in this study could accurately simulate an urban groundwater system. With the acceleration of urbanization, the urban groundwater system recharges by precipitation, and rivers tend to decline. The GW-ECC of ammonia nitrogen in Zhengzhou exhibited an overall upward trend. By the end of 2030, the GW-ECC of ammonia nitrogen is expected to reach a maximum of 1964.5 t. Changes in groundwater resources caused by precipitation and extraction were the main factors driving variations in the urban GW-ECC. In areas with mature urbanization, measures such as increasing groundwater recharge and reducing groundwater extraction are more effective in improving the GW-ECC. Full article

Research was conducted to examine the marketable yield and fruit weight of six strawberry cultivars (Fragaria × ananassa Duch. ‘Festival’, ‘Fortuna’, ‘Brilliance’, ‘Red Rhapsody’, ‘Sundrench’ and ‘Suzie’) over two years in subtropical Queensland, Australia. In the first year, the transplants were planted on 30 March, while in the second year, they were planted on 22 April. The average daily minimum temperature was 3 °C higher than the long-term average for the area from 1965 to 1990, while the average daily maximum temperature was 1 °C higher. Temperatures and solar radiation were similar in the two years of the study. In contrast, it was wetter in the second year (478 mm) than in the first year (332 mm). Average yield was lower in the second year (142 ± 10 g/plant) than in the first year (330 ± 9 g/plant) (p < 0.001), possibly due to a later planting. Higher rainfall in the second year may have also contributed to a higher incidence of rain damage and fruit rots. Yield was lower in ‘Sundrench’ (176 g/plant) than in the other cultivars (235 to 252 g/plant) (p = 0.003). Fruit weight was lower in the second year (18.2 g) than in the first year (23.8 g) (p < 0.001), and lower in ‘Festival’ and ‘Fortuna’ (18.2 and 19.4 g), intermediate in ‘Brilliance’, ‘Red Rhapsody’ and ‘Sundrench’ (21.0, 21.3 and 21.8 g) and higher in ‘Suzie’ (24.3 g) (p < 0.001). These results demonstrate that yield and fruit size vary in cultivars in Queensland. ‘Suzie’ had the largest fruit, favoring marketing. The low productivity of ‘Sundrench’ suggests that this cultivar is not commercially viable in Queensland. Yields are expected to decline in the future under global warming, in the absence of better-adapted cultivars and other mitigating strategies. Further evaluations of cultivars in Queensland are required under different growing practices, including earlier times of planting, higher plant densities, light shade and protected cropping. Full article

Climate change has the potential to significantly impact various aspects of Earth’s climate systems, including precipitation patterns, necessitating region-specific action plans. This study examines the Wadi Al Rummah region in Qassim province, Saudi Arabia, by analyzing Intensity-Duration-Frequency (IDF) curves across six locations, utilizing observed daily precipitation data from 1986 to 2014. The nonparametric quantile mapping method was employed to adjust the outputs of eight Regional Climate Models (RCMs) within the CMIP6 ensemble. These models were evaluated under four Shared Socioeconomic Pathways (SSPs), ranging from a stringent mitigation scenario to one with very high greenhouse gas emissions. Also, two statistical tests, namely the Kolmogorov-Smirnov and Chi-Square tests, were used to assess the best-fitting distribution to estimate the maximum rainfall values. Temporal disaggregation of daily precipitation data was performed using the K-nearest neighbors (KNN) method. The IDF curves were generated for both historical and three projected future periods using Gumbel distribution, which proved to be the best-fitting statistical model, using six return periods: 2, 5, 10, 25, 50, and 100 years. Results indicate that high-emission scenarios and longer timeframes exhibit greater uncertainty in IDF projections. Additionally, rainfall intensity is expected to increase over shorter durations, with significant increases observed in Buriydah and Nabhaniyah under SSP 8.5. In contrast, Al Rass, Badayea, and Al Mithnab show mixed trends, while Unaizah shows little to no significant change. These findings emphasize the need for sustainable development and adaptive strategies to mitigate risks in Qassim province, as climate impacts are projected to intensify, particularly in the short to long term. Full article