Dry Weather Research Articles

Seasonal dynamics of hydration of shoots of resource species of shrubs in the mediterranean subarid subtropics

An attractive region for tourism - the Southern Coast of Crimea, including the vicinity of the Nikitsky Botanical Garden – is experiencing a high year-round anthropogenic load. This has a negative impact on the conservation and renewal of woody and herbaceous resource species, many of which are ornamental, food and medicinal. As part of the study of the possibilities of renewing the resources of ornamental shrubs and assessing their adaptive potential in the conditions of the Mediterranean subtropics, the article characterizes the water content in buds and shoots based on the methodology for determining the percentage of water per dry mass. The dynamics of the hydration of shoots in winter, spring and autumn is shown. A comparative analysis of the saturation of shoots with water in unstable and stable species at different times of the year is carried out. Species with minimum and maximum water saturation of buds and shoots have been identified. The difference is indicated in the studied species in terms of water content before saturation in natural conditions and after, already in thelaboratory. Attention is drawn to the dependence of species stability on the month of saturation. The characteristic of saturation of plant tissues with water is given when weather conditions change in spring (rainy and dry weather, thaw) when modeling climatic conditions in the laboratory. The species in which the maximum saturation with water occurs both during imitation of rainy weather and during a thaw are highlighted. These studies were conducted for the first time on the described species in the conditions of the Mediterranean subtropics.

Unusual outbreaks of curly top disease in processing tomato fields in northern California in 2021 and 2022 were caused by a rare strain of beet curly top virus and facilitated by extreme weather events

In the western United States, curly top disease (CTD) is caused by beet curly top virus (BCTV). In California, CTD causes economic loss to processing tomato production in central and southern areas but, historically, not in the north. Here, we document unusual CTD outbreaks in processing tomato fields in the northern production area in 2021 and 2022, and show that these were caused by the rare spinach curly top strain (BCTV-SpCT). These outbreaks were associated with proximity of fields to foothills and unusually hot, dry, and windy spring weather conditions, possibly by altering migrations of the beet leafhopper (BLH) vector from locations with BCTV-SpCT reservoirs. Support for this hypothesis came from the failure to observe CTD outbreaks and BLH migrations in 2023, when spring weather conditions were cool and wet. Our results show the climate-induced emergence of a rare plant virus strain to cause an economically important disease in a new crop and location.

Interception performance of intake structures with a flow diversion barrier under supercritical flow conditions

Intake structures are commonly used in drainage systems to redirect surface rainfall runoff into underground tunnels. The Hong Kong West Drainage Tunnel (HKWDT) system is designed to capture stormwater from steep upland catchments during periods of heavy rainfall, concurrently maintaining a minimal environmental flow downstream during dry weather. However, during heavy rainfall events, excess rainfall water is often directed into the drainage system, presenting a significant challenge to the urban drainage system. Undistorted Froude scale physical models and computational fluid dynamics (CFD) models are developed to investigate the flow performance. In this study, effects of various design parameters on water diversion performance are examined across a wide range of inflow conditions. Steeper channel bottom slopes leading to a larger proportion of water being directed downstream. Extending the length of the bottom rack effectively reduces adhering flow. Introducing a transverse barrier generates a hydraulic jump, which increases flow diversion into the LFC. With higher barrier heights, the hydraulic jump becomes stronger, facilitating greater water diversion into the downstream sewage system. The results indicate potential solutions to these challenges and provide valuable insights into optimizing flow diversion performance in intake structures, particularly in areas characterized by steep terrains and varying flow conditions.

Potato Leaf Disease Prediction: A Machine Learning Perspective

Potato leaf disease has mostly two categories; early blight and late blight disease. The disease may be more prevalent in certain weather patterns and have a catastrophic effect on potato crops. In summary, warm, humid weather with frequent rain or heavy dew, temperatures between 15°C and 20°C, and a lack of sunshine are the weather conditions that can cause potato late blight. Drier weather conditions favour early blight, unlike late blight. Warm and dry weather with a lack of rain or irrigation, temperatures between 21°C and 29°C, and high humidity in the morning are the weather conditions that can cause potato early blight. A modified dataset is used for climate-influenced prediction, and the testing accuracy using random forest models is 97%. Analysis of experimental results shows that the suggested potato-leaf disease prediction based on the weather data framework outperforms the outcome of frameworks.

Anthropogenic influence on the state of Lake Shalkar in Western Kazakhstan

Lakes are natural accumulating systems with slow water exchange, acting as a regulator of river systems. Small lakes, which include water bodies with a surface area of up to 10-50 sq. km, are found everywhere and are actively used for economic and recreational purposes. Lake Shalkar is located in Western Kazakhstan and is the “Pearl of Kazakhstan”, where there are many vacationers in the summer. The summer months are characterized by bright, dry weather. The average air temperature in the territory in July is 23.6°C, the absolute maximum temperature reaches 41-45°C. The article studies the ecological state of Lake Shalkar. Research was carried out on several parameters: the organoleptic and hydrochemical properties of the lake water were studied, as well as the anthropogenic impact on the lake, since the lake, due to its unique properties, has recreational significance. In this regard, field trips to the lake were organized during the summer resort campaign in order to identify the anthropogenic load on the lake. A decrease in water turbidity was observed in summer. According to the data obtained, water does not differ in smell and taste from year to year. On average, organoleptic indicators do not change much; the smell is salty, easily detected, and may be the reason that the water is undrinkable, but suitable for bathing. In Lake Shalkar, the average water temperature was 14.7, the hydrogen index was 6.33, the concentration of oxygen dissolved in the water was 10.16 mg/dm3 BOD5 - 2.82 mg/dm3. Exceedances of the MPC were recorded for substances from the group of main ions (chlorides -6.7 MPC, sulfates -1.2 MPC).

Analysis of climatic factors affecting high-voltage overhead lines in the conditions of the Republic of Uzbekistan

The article analyzes the harsh climatic factors affecting the operation of high-voltage power lines in Uzbekistan with hot, dry weather and polluted atmosphere. Based on the analysis of all climatic factors affecting the operation of insulation and other nodes of overhead lines and high-voltage equipment in general, the severity of these factors is shown both in terms of insulation and energy efficiency. Another significant factor has been identified that has a very strong impact on the operation of overhead lines and high-voltage equipment, which was not previously listed in the list of influencing factors in any literature.

Organizational and technological solutions for controlling concrete structures projects in the dry hot weather in Iraq

Iraq has suffered from a long period of neglect in projects due to the circumstances it has experienced, and there is a great need to construct infrastructure and development projects. The weather in Iraq is characterized by an increasing rise in temperatures, with summer temperatures reaching 50°C and relative humidity around 24%. The summer season extends for 5 months, and this requires procedures and precautions in projects that include concrete structures in hot climates that represented by high temperatures and low humidity. Such weather would affect the properties of fresh and hardened concrete, as the rapid evaporation of water from the mix causes different damages to the concrete, the appearance of shrinkage cracks, as well as a lack of workability. It also affects the strength of the concrete and its durability at later ages. Also, there are other problems in such projects related to poor quality and increased costs and time required to implement construction projects. Therefore, problems related to hot climates were studied through literature review in this regard. A questionnaire was also conducted to show the real problems that these projects suffer from, and problems were found that go beyond providing the above precautions that must be available in hot weather. Rather, it requires an increase in allocations, and there are problems related to the need for planning, as well as the necessary administrative, technical and legislative measures to improve performance.

Side-by-Side Testing of Grit Separation Units

Two grit removal systems were tested side-by-side for the treatment of wastewater from a combined-sewer system. The two units were operated at constant flows and variable grit loads ranging from 1.2 to 745 Kg/m3 /h that covered the typical range of dry and wet weather conditions experienced at the treatment facility. The average mass grit removal for the multi-tray free vortex unit was 92.6% and it was 85.4% for the forced vortex system. Both units consistently failed to remove particles with sand equivalent sizes, which their respective overflow rates would otherwise predict. This observation can be explained by uneven force distributions over non-spherical grit particles with lumpy grease deposits and variable curvature that effect motion traverse to flow, increase buoyancy and cause particle lift.

Dry Weather Adaptations in Wastewater Treatment: Innovative Control Strategies for Effective Organic and Nitrogen Elimination

Through a meta-heuristic framework, this study examines various wastewater treatment methods in detail and proposes a novel application of genetic algorithms (GAs) in plant optimization. ASM models are adapted to include ion speciation and pairing models, and microplastics (MPs) are challenged, indicating the need for further research. An integrated model accounts for carbon, nitrogen, phosphorus, oxygen, and hydrogen, emphasizing pH’s crucial role in biological treatment processes by examining microbial growth rates and organic compound removal. By applying natural selection and evolutionary processes, GAs are investigated as an optimization tool for plants, improving gene sequence structures and, by extension, treatment processes. The importance of this is particularly evident when dealing with non-standard numerical solutions and algebraic calculations. A robust and adaptable wastewater treatment strategy that accommodates variable weather conditions is provided by the study, which illustrates GAs, their stopping conditions, and the selection process for fitness functions.

Predicting Forest Fire Hotspots with Carbon Emission Insights Using Random Forest and Gradient Boosting Regression

This research paper focuses on predicting the dispersion of carbon emissions, a crucial indicator for identifying potential forest fire hotspots in the wooded regions of Sumatra Island, Indonesia. Forest fires, often triggered by extended periods of dry weather, result in significant environmental degradation, impacting both the ecosystem and the economy. Furthermore, health concerns arise from smoke inhalation, leading to respiratory problems. To achieve this predictive capability, we harnessed valuable datasets, including GFED4.1s for carbon emissions and ERA5 for historical climate indicators, spanning from 1998 to 2022. Employing supervised learning ensemble methods, specifically Random Forest Regression (RFR) and Gradient Boosting Regression (GBR), we sought to forecast carbon emissions. It is noteworthy that our predictions encompassed carbon emission values from 1998 to 2023, providing insights into recent trends. Our analysis showed that GBR did better than RFR in terms of evaluation metrics, with a root mean square error (RMSE) of 10.87 and a mean absolute error (MAE) of 2.91. This was done by carefully tuning the hyperparameters. Additionally, our study highlighted that precipitation, temperature, and humidity were the primary climate factors influencing carbon emission values.

Application of SWMM in the simulation of point source pollution in a macrodrainage system

Many cities in Brazil still present, in some locations, flaws in the urban drainage system, mainly concerning water contamination by punctual and diffuse sources, with drainage channels visibly contaminated by domestic sewage and solid waste. Therefore, the present study aimed to perform the diagnosis of dry weather flows and evaluate the behavior of pollutant concentrations during the propagation of the flow and the response of mathematical modeling to an intervention proposal in case the punctual entries that present greater polluting potential to be removed, aiming at improving the quality channel waters. The identification of the sewage entry points in the Canal do Prado was based on field observations. The flow measurement was made at each selected point, to better understand the flow behavior and obtain a good average for the analyzed period. To perform the simulation, the concentrations of the variables BOD, COD and FT for the sewage inlets were raised. A diagnosis of dry weather flows was carried out, corresponding to the reality of the drainage system in the non-rainy periods of the city. The results indicate that SWMM responds well to the Dry Climate Flow (DWF) simulation. Furthermore, even small interventions done in the canal would not yield a significant improvement in the overall quality of the drainage system of the basin, the improvements would be only local.

A Computationally Efficient Method to Determine the Probability of Rainfall-Triggered Cut Slope Failure Accounting for Upslope Hydrological Conditions

We present a new computationally efficient methodology to estimate the probability of rainfall-induced slope failure based on mechanical probabilistic slope stability analyses coupled with a hydrogeological model of the upslope area. The model accounts for: (1) uncertainty of geotechnical and hydrogeological parameters; (2) rainfall precipitation recorded over a period of time; and (3) the effect of upslope topography. The methodology provides two key outputs: (1) time-varying conditional probability of slope failure; and (2) an estimate of the absolute frequency of slope failure over any time period of interest. The methodology consists of the following steps: first, characterising the uncertainty of the slope geomaterial strength parameters; second, performing limit equilibrium method stability analyses for the realisations of the geomaterial strength parameters required to calculate the slope probability of failure by a Monte Carlo Simulation. The stability analyses are performed for various phreatic surface heights. These phreatic surfaces are then matched to a phreatic surface time series obtained from the 1D Hillslope-Storage Boussinesq model run for the upslope area to generate Factor of Safety (FoS) time series. A time-varying conditional probability of failure and an absolute frequency of slope failure can then be estimated from these FoS time series. We demonstrate this methodology on a road slope cutting in Nepal where geotechnical tests are not readily conducted. We believe this methodology improves the reliability of slope safety estimates where site investigation is not possible. Also, the methodology enables practitioners to avoid making unrealistic assumptions on the hydrological input. Finally, we find that the time-varying failure probability shows marked variations over time as a result of the monsoon wet–dry weather.

Analysis of suspended solids emissions from a combined sewage system using the Stormwater Management Model (SWMM)

The protection of water bodies requires the reduction of pollutant emissions from all major sources. In urbanized areas, these include: wastewater treatment plants (WWTPs) and (depending on the type of sewage system) combined sewer overflows (CSOs) and stormwater drainage outlets. WWTPs are usually monitored and emitted pollutant loads are known, but it is more difficult to assess the pollutant load discharged by CSOs and stormwater drainage systems. The article attempts to use the Stormwater Management Model (SWMM) to assess emissions of suspended solids from a large urban combined catchment. Suspended solids are the main pollutant of stormwater runoff in urban areas, and the dynamics of their emission from catchments is very diverse. The amount of suspended solids discharged by CSOs functioning in the given city was assessed in comparison with emissions from a wastewater treatment plant. The results show that CSOs discharge a pollutant load to the receiver which is comparable to WWTPs, but in a much shorter time and in a violent manner which can lead to the severe deterioration of receiving water quality. The modelling took into account the quality of dry weather sewage, the build-up of suspended solids, wash-off processes in the catchment area, and local precipitation characteristics. Factors affecting the quality of the obtained model and the accuracy of the emission level assessment were analysed.

CO2 Emissions from Soils under Different Tillage Practices and Weather Conditions

CO2 emissions are one of the greenhouse gases that significantly contribute to climate change. The use of reduced soil tillage practices could contribute to the mitigation of CO2 emissions from soils under ongoing climate change conditions. The use of reduced and no-tillage practices in the summer period, the most critical period for CO2 and for water loss from soils, would contribute to the mitigation of CO2 emissions that is required by the European Union. The aim of this research was to contribute to the specification of CO2 emission factors, following different soil tillage practices in the summer period under variations in weather. Gentler tillage practices were defined in terms of reducing CO2 emissions from the soil. This research was carried out as a long-term field experiment. The effects of soil tillage practices on CO2 emissions were studied over a six-year period as a long-term field experiment and concerned the use of different soil tillage practices for over 20 years (established in 1995), with these including conventional tillage (CT; plowing to 20–22 cm), reduced tillage (RT; chiseling to 10 cm), and no-tillage (NT; without tillage). The crop rotation was winter wheat–winter oilseed rape–winter wheat–pea. CO2 emissions were measured at least 7–10 times during the summer–autumn period in the years 2017–2022 after agrotechnical operations following the winter wheat harvest. Soil moisture was determined in all the treatments. Weather conditions were measured by means of the meteorological station of the Crop Research Institute. The CO2 emissions were the highest in the summer period under CT in comparison with RT and NT. Reduced tillage and no-tillage practices, with mulch on the surface of the soil, decreased CO2 emissions by a 6-year average of 45% and 51%, respectively. The mean CO2 emissions were 6.1, 3.1, and 2.9 μmol CO2 m−2 s−1 for CT, RT, and NT. The highest CO2 emissions and the largest differences among different tillage practices were measured in 2019, with high temperatures and repeated rainfall. CO2 emissions under CT reached 22 μmol CO2 m−2 s−1, which was 7.5 and 5.8 times higher than under RT and NT, respectively. Current weather conditions, mainly temperature and precipitation, played an important role in CO2 emissions. The hot and dry weather in 2018 decreased overall CO2 emissions, with CO2 emissions, even under conventional tillage, reaching only 2.5 μmol CO2 m−2 s−1 on average. As a result of climate change, the temperatures also gradually increased in the later stages of the year, with more summer days being expected during autumn and higher CO2 emissions from soils being expected as a result.

How Have Hydrological Extremes Changed over the Past 20 Years?

Abstract Severe floods and droughts, including their back-to-back occurrences (weather whiplash), have been increasing in frequency and severity around the world. Improved understanding of systematic changes in hydrological extremes is essential for preparation and adaptation. In this study, we identified and quantified extreme wet and dry events globally by applying a clustering algorithm to terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (FO). The most intense events, ranked using an intensity metric, often reflect impacts of large-scale oceanic oscillations such as El Niño–Southern Oscillation and consequences of climate change. The severity of both wet and dry events, represented by standardized TWS anomalies, increased significantly in most cases, likely associated with intensification of wet and dry weather regimes in a warmer world, and consequently, exhibited strongest correlation with global temperature. In the Dry climate, the number of wet events decreased while the number of dry events increased significantly, suggesting a drying trend that may be attributed to climate variability and possible increases in irrigation and reliance on groundwater. In the Continental climate where temperature has risen faster than global average, dry events increased significantly. Characteristics of extreme events often showed strong correlations with global temperature, especially when averaged over all climates. These results suggest changes in hydrological extremes and underscore the importance of quantifying total water storage changes when studying hydrological extremes. Extending the GRACE/FO record, which spans 2002 to the present, is essential to continuously tracking changes in TWS and hydrological extremes.

THE IMPACT OF DUST POLLUTION FROM UNPAVED ROADS IN THE AKAMAS PENINSULA, CYPRUS, USING UAV AND SENTINEL-2 IMAGES

Abstract. This study examines the effects of dust in the Akamas National Park in Cyprus generated from traffic over the unpaved roads on the roadside vegetation. The Akamas National Park is located on the western tip of Cyprus and covers an area of about 230 km2, containing valleys, gorges and wide sandy bays. Akamas is a mountainous, relatively inaccessible area to standard vehicles and protected from man-made development. It is home to hundreds of animal species and plants that are essential for the ecology of the Mediterranean region. There are several unpaved roads to access the area and more than one million people visit the Akamas peninsula each year, mostly in the summer period, primarily in 4X4 and all-terrain vehicles, which are rented in the nearby area. This unregulated traffic results in dust, especially during the dry weather conditions in the summer that can fall up to a kilometre away on all sides of the vehicle. In this study, images acquired from an Unmanned Aerial Vehicle (UAV) of the roads within the Akamas peninsula were compared with Sentinel-2 satellite images during different seasons. Using the Normalized Vegetation Index (NDVI) from the Sentinel-2 images, it was shown that the vegetation nearest to the unpaved roads exhibited pronounced stress compared to the vegetation that was more distant. Also, spectral signatures as well as infrared and thermal images were taken at different distance intervals from the unpaved road.

Metal toxin threat in wildland fires determined by geology and fire severity

Accentuated by climate change, catastrophic wildfires are a growing, distributed global public health risk from inhalation of smoke and dust. Underrecognized, however, are the health threats arising from fire-altered toxic metals natural to soils and plants. Here, we demonstrate that high temperatures during California wildfires catalyzed widespread transformation of chromium to its carcinogenic form in soil and ash, as hexavalent chromium, particularly in areas with metal-rich geologies (e.g., serpentinite). In wildfire ash, we observed dangerous levels (327-13,100 µg kg−1) of reactive hexavalent chromium in wind-dispersible particulates. Relatively dry post-fire weather contributed to the persistence of elevated hexavalent chromium in surficial soil layers for up to ten months post-fire. The geographic distribution of metal-rich soils and fire incidents illustrate the broad global threat of wildfire smoke- and dust-born metals to populations. Our findings provide new insights into why wildfire smoke exposure appears to be more hazardous to humans than pollution from other sources.

A cross-sectional survey on the effects of ambient temperature and humidity on health outcomes in individuals with chronic respiratory disease.

Extremes of temperature and humidity are associated with adverse respiratory symptoms, reduced lung function, and increased exacerbations among individuals living with chronic obstructive pulmonary disease (COPD). To describe the reported effects of temperature and humidity extremes on the health outcomes, health status and physical activity (PA) in individuals living with COPD. A cross-sectional self-reported survey collected the effects on health status (COPD Assessment Test [CAT]), PA, and health outcomes in 1) moderate/ideal (14 to 21°C, 30 to 50% relative humidity [RH]), 2) hot and humid (≥ 25°C, > 50% RH) and 3) cold and dry (≤ 5°C, < 30% RH) weather conditions. Participants were ≥ 40 years old with COPD or related chronic respiratory diseases (e.g., asthma, sleep apnea, interstitial lung disease, lung cancer) and residing in Canada for ≥ 1 year. Negative responders to weather extremes were a priori defined as having a change of ≥ 2 points in the CAT. Thirty-six participants responded; the mean age (SD) was 65 (11) years, and 23 (64%) were females. Compared to ideal conditions, 23 (66%) and 24 (69%) were negatively affected by cold/dry and hot/humid weather, respectively. Health status was significantly lower, and PA amount and difficulty level were reduced in hot/humid and cold/dry conditions compared with ideal conditions. The number of exacerbations in hot/humid was significantly higher compared to ideal conditions. More participants were negatively affected by extremes of weather: health status worsened, PA decreased, and frequency of exacerbations was higher compared to ideal. Future prospective studies should directly and objectively investigate different combinations of extreme temperature and humidity levels on symptoms and PA to understand their long-term health outcomes.

Inter-event and intra-event dynamics of microplastic emissions in an urban river during rainfall episodes

Urban rivers represent the major conduits for land-sourced microplastics in the global oceans, yet the real-time dynamics of their emissions in rivers during rainfall (and runoff) events are poorly understood. Herein, we report the results of high-frequency sampling of microplastic particles (MPs) and fibers (MPFs) in the surface water of an urban river in Japan over the course of three rainfall events (i.e., light, moderate, and heavy rainfalls). The event mean concentrations (EMCs) of MPs amounted to 35,000 items/m3, 929,000 items/m3, and 331,000 items/m3; and the corresponding total loads were 0.5 kg, 19.8 kg, and 35.0 kg for light, moderate and heavy rainfalls, respectively. The inter-event total loads of MPs correlate well with the total rainfall, while the concentrations were linked with the number of antecedent dry days. The dynamic trends show that <2000 μm MPs displayed first flush effects during light to moderate rainfall events (>50% mass discharged with the initial 20–40% of flow). Small-sized MPs (10–40 μm) mobilized rapidly at lower rainfall intensities, whereas MPs over 2000 μm discharged immediately after the peak rainfall intensity. Moreover, <70 μm MPs depicted a surge following heavy rainfall events due to turbulent flow conditions reverting the deposited MPs into suspension. Overall, the three events increased the loads by 4–110 folds, and EMCs by 10–350 folds compared to the concentrations during dry weather while portraying a significant impact on 300–1000 μm MPs. The dynamics of MPs were correlated with those of suspended solids in river water, and the characteristics were comparable to the same of road dust sampled in Japan. Although the dynamic trends between MPs and MPFs in river water were comparable, MPFs were relatively less impacted by rain, likely due to the intervention of separate sewer systems in the study area.

Laser nanoengineered coatings for efficient energy transportation through corona discharge suppression

Overhead high-voltage transmission lines are crucial for the modern power transportation industry, but their operation in an open atmosphere raises concerns regarding durability, corona discharge, and leakage currents, which have economic and environmental impacts. To mitigate these issues, new functional materials are being developed using laser nanotechnology, such as superhydrophobic, superhydrophilic, and SLIPS coatings. The suitability of each coating depends on specific operating conditions, requiring a compromise between various wire properties. In this study, we investigated the efficiency of these coatings in reducing corona discharge currents under dry and rainy weather conditions. Our research showed that superhydrophobic and superhydrophilic coatings effectively reduce corona discharge currents by up to 2–4 times, while SLIPS coatings, despite water-repellent properties, increase corona currents in rainy conditions. The obtained results allow suggesting two promising paths toward the improvement of corona protection by enhancing the durability of superhydrophobic coatings under intermittent prolonged rainy conditions and reducing ice adhesion to superhydrophilic coatings.