Rainfall Research Articles

Torrents of Sediment-Laden Water Worsened Disastrous Libyan Floods

Drought followed by torrential rain can unleash deadly floods in arid regions, like those that affected Libya in 2023.

Coordination mechanisms applied to logistical systems for local disaster preparedness: a Latin American case

Purpose The study aims to present an agent-based simulation model (ABM) for exploring interorganizational coordination scenarios in local disaster preparedness. This approach includes local actors and logistical processes as agents to compare various strategic coordination mechanisms. Design/methodology/approach The ABM model, developed in the Latin American context, specifically focuses on a case study of Colombia. Three coordination mechanisms (centralized, decentralized and cluster-type) have been evaluated using three performance indicators: effectiveness, efficiency and flexibility. Findings Simulation results show that the decentralized scenario outperforms in terms of efficiency and flexibility. On the contrary, the centralized and cluster-type scenarios demonstrate higher effectiveness, achieving a greater percentage of requirements coverage during the disaster preparedness stage. The ABM approach effectively evaluates strategical coordination mechanisms based on the analyzed performance indicators. Research limitations/implications This study has limitations due to the application of results to a single real case. In addition, the focus of the study is primarily on a specific type of disaster, specifically hydrometeorological events such as flash floods, torrential rains and landslides. Moreover, the scope of decision-making is restricted to key actors involved in local-level disaster management within a municipality. Originality/value The proposed ABM model has the potential as a decision-making tool for policies and local coordination schemes for future disasters. The simulation tool could also explore diverse geographical scenarios and disaster types, demonstrating its versatility and broader applicability for further insights and recommendations.

Emergency Preparedness for Waterborne Diseases in the Wake of Floods in Northern Cameroon: A Call for Immediate Action

Severe flooding in Northern Regions of Cameroon (Far North, North and Adamawa Regions), triggered by torrential rains, has led to widespread displacement, destruction of infrastructure, and significant disruptions in essential services, particularly water, sanitation, and healthcare. This article, issued by public health researchers from Science For Life Foundation and Pinnacle University Institute, highlights the heightened risk of waterborne diseases following the recent floods and underscores the urgent need for enhanced emergency preparedness and response measures. Floods create conditions conducive to the spread of diseases such as cholera, typhoid fever, dysentery, and viral hepatitis by contaminating drinking water supplies with sewage and waste. Vulnerable populations, including children, pregnant women, the elderly, and those with pre-existing health conditions, are at increased risk. Overcrowding in temporary shelters further exacerbates the potential for disease outbreaks. The impact of climate change is intensifying the frequency and severity of such flooding events, making timely and effective intervention critical. This article reviews best practices for preventing and mitigating waterborne disease outbreaks, offering guidance to government authorities, health agencies, humanitarian organizations, and local communities. It aims to catalyze immediate action to safeguard public health and prevent a major crisis in the aftermath of the flooding Keywords: Waterborne Diseases, Flooding, Emergency Preparedness.

Effect of Conservation Agricultural Practices on Crop Yield and Soil Properties Under Sorghum [Sorghum bicolor (L.) Moench] — Black Gram [Vigna mungo (L.) Hepper] System in Rainfed Alfisol

ABSTRACT A long-term study was conducted to assess the effect of tillage (conventional, CT and minimum, MT) and residue retention treatments on crop yields, sustainable yield index (SYI), rain water use efficiency (RWUE) and soil properties under sorghum – black gram system in resource poor Semi-Arid Tropical (SAT) Alfisol at Hyderabad, India. The results revealed that when averaged over residue retention treatments, MT recorded 12.32 and 5.21% higher sorghum and black gram grain yield, 19.61 and 25.93% higher sustainability yield Index (SYI), and 12.27 and 5.15% rain water use efficiency (RWUE), respectively, over conventional tillage. Residue retention treatments (averaged over tillage treatments) S2 (cutting at 60 cm height for sorghum and 100% retention for black gram) and S1 (cutting at 35 cm height for sorghum and 50% retention for black gram) recorded 33.16 and 16.16, and 32.18 and 14.88% higher sorghum and black gram yield, respectively, over S0 (no residue) and also recorded 26.0 and 9.0, and 48.0 and 22.0% higher SYI over S0 in sorghum and black gram, respectively. Increase in RWUE under S2 and S1 over S0 was 33.19 and 16.23% in sorghum and was 31.4 and 14.53% in black gram. Higher residue retention maintained significantly higher soil organic carbon (SOC), significantly lower bulk density (BD) and significantly influenced potential of hydrogen (pH) and electrical conductivity (EC) at all the depths and also increased available nitrogen (N), phosphorus (P), potassium (K), manganese (Mn), iron (Fe), zinc (Zn) and copper (Cu) by 35.43, 24.55, 12.12, 57.6, 53.99, 51.46 and 13.76%, respectively. Thus, the results of the present study are highly useful in improving the crop yields, yield sustainability and soil properties. Therefore, the conservation agriculture practices can be a resource saving and higher crop production technology in the rainfed Alfisols.

The impact of IPOD on boreal midsummer extratropical cyclones accompanied by torrential rains in Central and Eastern China

The impact of IPOD on boreal midsummer extratropical cyclones accompanied by torrential rains in Central and Eastern China

Acid rain and comparative study of rain water

Acid rain and comparative study of rain water

GEOCHEMISTRY OF GROUNDWATERS AND SURFACE WATERS, AND GROUND ICE OF THE OKA PLATEAU, EASTERN SAYAN (RUSSIA)

The study area is located in the Eastern Sayan hydrogeological folded area. The objects of the study were groundwaters, surface waters and ground ice in the Sentsa River basin on the Oka Plateau. Cold and thermal groundwaters are associated with Proterozoic and Paleozoic metamorphic and igneous rocks. Their discharge as springs occurs in the river valleys along fault zones. Ground ice was studied in mineral frost mounds (lithalsas) composed of clays, clayey silts and silts of lacustrine-alluvial and fluvioglacial genesis. It has been established that thermal and cold groundwaters have HCO3 Ca-Na compositions, river and lake waters, as a rule, have HCO3 Ca-Na compositions, and ground ice melts – HCO3, SO4-HCO3 and NH4-HCO3 Ca. Thermal waters are largely enriched in Li, Be, B, Si, Mn, Ga, Ge, Se, As, Br, Rb, Sr, Cs, Ba and all REE relative to river and rain waters, and have the highest values of trace elements enrichment factor (EFREE). The latter shows that atmospheric precipitation participates in the formation of the composition of groundwaters (cold and thermal) and surface waters. The specificity of the geochemistry of ground ice is determined by the composition of precipitation, the injection of ice-forming groundwater from taliks, the interaction in the water-rock system, and the presence of organic matter in unconsolidated sediments. The participation of river water and groundwater in the formation of the frost mound ice core is also evidenced by similar values of stable isotopes (δ18O, δD) in surface water, groundwater and ground ice. The 3He/4He ratio points to a possible influx of mantle helium into thermal waters, and δ13С points to the magmatic and thermometamorphic mechanisms of carbon dioxide accumulation in thermal waters. The 87Sr/86Sr ratio in travertines indicates a significant contribution of intrusive rocks to the formation of fluid composition.

Influence of meteorological factors on intraocular pressure variability using a large-scale cohort

The effects of meteorological conditions on IOP using a large-scale health examination cohort were investigated. There were a total of 811,854 measurements from 126,630 eyes of 63,839 subjects in 9 years from a health checkup cohort followed up annually for age, sex, body height, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), and IOP. The effects of these variables and the meteorological data of daily average temperature (TP), daily average local atmospheric pressure (AP), daily average volumetric humidity (VH), and daily amount of rainfall (RF) on the day of IOP measurement on IOP were investigated. Several variables were significantly associated with IOP, including sex, age, body height, BMI, SBP, DBP, average TP, average AP, average VH, RF, white blood cell count, red blood cell count, hemoglobin, aspartate aminotransferase, alanine aminotransferase, guanosine triphosphate, calcium, and HbA1c. This study indicated a correlation between meteorological factors and IOP. Higher AP and RF were associated with elevated IOP, whereas higher TP and VH were associated with decreased IOP.

The δ2H and δ18O isotopic evidence for hydraulic redistribution by Alnus acuminata in an agricultural landscape

Understanding of the process of hydraulic redistribution in agricultural landscapes is important for informing agroforestry design and agricultural management. The measurement of hydraulic lift and redistribution in the field is still a challenge. Due to the robustness of stable isotope analysis, we hypothesized that the measurement and analysis of the natural abundance of stable isotopes δ2H and δ1⁸O, in the twigs of agroforestry trees, stems of wheat intercrop, rain, and soil water coupled to an isotopic mixing modeling by IsoSource supplemented with other physiological crop parameters, would estimate the extent of hydraulic redistribution in intercropping, and inform the design of an agroforestry system. There are still many plant species that have not been investigated for their potential hydraulic redistribution yet, and Alnus acuminata is among them, therefore this study aimed to contribute to filling that gap. The field experiment was conducted in an Andic soil of the northern Rwanda highlands to address the extent of water efflux redistribution from tree roots of Alnus acuminata to the wheat intercrop across bench terraces. The study involved the measurement of the natural abundance of stable isotopes δ2H, and δ1⁸O of the tree twigs, soil and wheat stems at distances of 1, 3, 5, and 7 m from the tree lines of Alnus acuminata, and of rainwater. The isotopic mixing modeling was supplemented by measuring both specific leaf area (SLA) and carbon discrimination (Δ13C) in the wheat leaf. We noted a significant (p < 0.01) gradient in the depletion of wheat xylem water δ2H and δ18O signatures moving further away from the tree lines. Based on the wheat value of δ2H, the isoSource indicated that the trees may have contributed the wheat water up to 64.3 ± 2.6% at 5 m from the trees, and the values of both the SLA (cm2 g–1) and ∆13C (‰) of wheat leaf indicated the water use efficiency of wheat significantly improved around the trees up to 3 m away from the trees with 140.10 ± 3.74 cm2 g–1, 149.56 ± 3.43 cm2 g–1 and 20.6 ± 0.1‰, 20.8 ± 0.1‰ at 1 m and 3 m for SLA and ∆13C respectively. We concluded that Alnus acuminata exhibits significant hydraulic redistribution in the field.

Microphysical characteristics of torrential predecessor rain events over the Yangtze River Delta Area and the related tropical cyclones

The precipitation structures and microphysical characteristics of predecessor rain events (PREs) over the Yangtze River Delta area and related tropical cyclones (TCs) from 2014 to 2019 were investigated using Dual-frequency Precipitation radar data from Global Precipitation Measurement (GPM) for drop size distributions (DSDs). Results showed that the total mean rain rate of PREs was larger than that of TCs, primarily due to higher convective and stratiform rain rates, with enhanced fractional coverage of convective rain in PREs. Examination of microphysical characteristics revealed that a greater quantity of small-sized droplets and a smaller quantity of medium- as well as large-sized droplets contributed towards PREs in comparison with TCs. The conclusion still holds when partitioning DSDs based on different precipitation rate categories. Further investigation of DSDs using gamma functions illustrated that precipitation in PREs had lower average mass-weighted diameters (Dm) and enhanced normalized number concentration (Nw) compared with TCs; partitioning precipitation into convective and stratiform components illustrated a larger Dm and lower Nw in TCs than PREs. The analysis of microphysical and thermodynamical processes using the reanalysis data indicates that relatively intense convective activity with drier conditions may be favorable to enhancing raindrop growth through collision-coalescence processes, as a result of larger Dm in TCs than PREs. The empirical relations (Z–R algorithms) applied in different rain regimes (stratiform, convective, and total PREs) revealed significant diversities, relying on weather conditions and geographical locations. Plain language summaryThe Yangtze River Delta area is an important economic belt in China. Under climate change, observed frequent occurrences of weather extremes of heavy rainfall and tropical cyclones (TCs) exert adverse effects on economic development in this region. Thus, a deep understanding of the mechanism of TCs torrential rainfall in the Yangtze River Delta area is urgently necessary. In this study, we investigated the precipitation patterns and microphysical characteristics of predecessor rain events (PREs) in the Yangtze River Delta region, and their association with TCs in the South China Sea-Western North Pacific Ocean (SCS-WNPO) area from 2014 to 2019. We found that PREs had a higher total mean precipitation rate than TCs. Further examination using gamma functions demonstrated that PREs exhibited lower average mass-weighted diameters (Dm) and higher normalized intercept parameters (Nw) than TCs. This pattern persisted when distinguishing between convective and stratiform precipitation components. We believe that our study makes a significant contribution to the literature because these results provide valuable insights into the distinct precipitation characteristics of PREs and TCs in the study region and contribute to a better understanding of tropical cyclone-related rainfall patterns, and act as a scientific basis for disaster mitigation.

The changing characteristics of torrential rainfall in the Huaihe River Basin from 1961 to 2020

Abstract The Huaihe River Basin (HRB) is one of the most severely affected regions by torrential rain disasters in China. However, with climate warming, it is unclear what new features torrential rain exhibits and how the main modes of torrential rain change in this region. This study analyzes the first two modes of torrential rain in the HRB from 1961 to 2020 and their driving factors. Results show that in the last 30 years, the frequency of torrential rain events in the HRB has clearly increased, especially in southern HRB region during the flood season. The first mode of torrential rain is an entire basin-wide mode, with a period of 2–3 years. The mode is primarily influenced by the low-level westerly jet stream and Jianghuai cyclones, which are closely linked to the stratospheric Quasi-Biennial Oscillation (QBO) through influencing planetary wave propagation and convective activity under different phases of QBO. The second mode is a north-south distribution mode, with a period of 4–6 years. The leading circulation system is the frontal systems. Both the East Asia/Pacific (EAP) teleconnection wave train and ENSO drive the second torrential rain mode. During El Niño years, anomalous subsidence and anticyclone in the western tropical Pacific, induced by sea surface temperature warming in the eastern tropical Pacific through the East Asia/Pacific teleconnection, can trigger the EAP wave train poleward in the East Asian region. This wave train leads to the cold-warm confrontation conducive to the second torrential rain mode.

Identifying Groundwater Recharge Sources and Mechanisms using Hydrochemistry and Environmental Stable Isotopes in High Arsenic Holocene Aquifers of Bangladesh

Und erstanding the sources and mechanisms of aquifer recharge is critical for water resource management. So far, this is the first comprehensive study to explore the sources and mechanisms of groundwater recharge applying stable environmental isotopes and hydrogeochemical properties in Southwestern Bangladesh. Water samples from the different sources (groundwater, surface (pond), river and rain water) of high arsenic (As) Holocene aquifers were used to investigate the chemical tracers and environmental stable isotopes (δ18O and δ2H) to explore the hydrogeological features, groundwater recharge sources, mechanisms and processes. The analytical results showed high As concentration in water samples observed 590.7 μg/L. High As groundwater was identified by a low pH value, medium HCO3- and TDS with low concentration of NO3- and SO42-. However, depleted δ2H and δ18O signatures indicated that local vertical rainfall is the key source to recharge groundwater in study area. The recharge process from pond seepage and irrigation return flow also contribute in groundwater recharge. Isotopic signatures suggested the vertical connectivity amongst the aquifers and significant vertical recharge. The reduced heavier isotope reveals extra recharging from floods of mountains and high altitude. Due to the heterogeneous and anisotropic structure of the aquifer system the spatial variability of δ2H and δ18O shows limited lateral connectivity. The combined analyses of δ2H isotope and Cl- ion showed that evaporation is the primary cause for groundwater discharge. Based on the spatial and vertical recharge processes of groundwater, present study provides a crucial baseline knowledge for establishing a sustainable groundwater management strategy. The findings from this study can guide the development of targeted groundwater management strategies and improvement of understanding the groundwater recharge sources and processes.

Specific Weather Factors Affecting the Incidence of Fire Blight in Korea from 2020 to 2023

Since its initial outbreak in Korea in 2015, fire blight has consistently emerged annually. Fire blight outbreaks usually begin in May, peak in June, and decline in July in Korea. In this study, we analyzed cases that exhibit a distinct pattern of disease occurrence based on yearly weather conditions from 2020 to 2023. In 2020, fire bight disease occurrence began in late May. Although the disease incidence started late by the low temperatures in April, which caused flowering period delayed, the incidence increased significantly due to the high risk of blossom infection. In 2021, the first outbreak began in late April because the flower infection started in early April. In 2022, despite the high blossom infection risk during the flowering period in April and the high incidence of fire blight in May, the incidence decreased sharply from June due to the low rainfall in May. In 2023, due to torrential rains and hail in late June, the incidence of fire blight increased even in July. Considering the weather factors that affect the increase of fire blight disease, it is suggested that control measures to prevent the fire blight infection should be carried out before and after wind-driven rains.

Linking recharge water sources to groundwater composition in the Hindon subbasin of the Ganges River, India

Groundwater resources of the densely populated Indo-Gangetic Basin are under increasing pressure, not only from extensive groundwater abstraction, but also from contamination. In this study we aim to better understand how different recharge sources affect the hydrochemical and isotope composition of groundwater. We used the Hindon subbasin in Northern India as a case study. Recharge water sources and groundwater were analysed for hydrochemical variables and stable isotopes along a 50 km transect between the Yamuna and Ganges rivers. Groundwater samples were statistically clustered based on hydrochemical variables, and the spatial variation of the groundwater clusters was compared with recharge sources.Groundwater quality could be linked to both recharge from irrigation canal water as well as recharge from polluted river water of the Hindon and its tributaries. We could not directly link groundwater outside these related zones to their recharge source. However, we suspect that shallow polluted groundwater (< 40 m depth) is affected by recharge from agricultural areas and infiltration of municipal wastewater, whereas deeper unpolluted groundwater (40–80 m depth) originates from recharge by rain and river water under more pristine conditions. Our findings show that human activities significantly impact the quality of groundwater, as we found vertical recharge of clean irrigation canal water and polluted municipal, agricultural and river surface water (up to 40 m depth). At one location, groundwater at 75 m depth shows increased Cl, NO3 and SO4 concentrations, suggesting accelerated downward displacement of polluted shallow groundwater by pumping. Limited horizontal displacement was found. We present a conceptual model demonstrating the evolution from a previously unpolluted groundwater system discharging to the river, to a contemporary system with infiltration dominance of polluted river, municipal and agricultural water and local clean irrigation canal water. This model may be relevant for large parts of the Indo-Gangetic Basin.

Can temperature be a low-cost tracer for modelling water age distributions in a karst catchment?

To investigate the feasibility of using temperature for tracking rainfall-runoff processes in karst catchments, this study developed a tracer-aided conceptual model using temperature as a tracer by coupling water and heat transport processes at the catchment scale. The model was calibrated and validated using hourly hydrometeorological and temperature data from a 1.25 km2 karst catchment in south-western China. The results showed that the model was able to capture the water flux and temperature dynamics of different landscape units in the karst catchment. Utilizing this framework, the model delineated the flux age distribution within different landscape units, as well as the overall water transit times through the catchment. The average flux ages were determined to be approximately 80 days for the hillslope unit, 452 days for the slow flow system, and 260 days for the fast flow regime within the depression areas. These estimations align broadly with those acquired using stable isotopes as tracers. Comparative analysis revealed that the flux age distributions derived from both temperature and isotopic tracers exhibited analogous patterns at the catchment outlet and across the hillslope compartments. However, the simulations based on temperature hinted at a heightened proportion of exceedingly young and decidedly old water in the outflow, alluding to a potential overestimation of these extreme age classes by the temperature-tracer model. From the temperature-simulated transit time distribution, about 31 % of the precipitation entering during the study period have left the catchment within 3 years, and a notable proportion of rain water was either stored in the aquifer or lost through evapotranspiration. The general characteristics of the transit time distribution simulated using temperature was similar with that simulated using isotopes, though a higher proportion of precipitation being drained by fast flows was inferred from the transit time distribution simulated using temperature. Collectively, our study demonstrated that temperature can serve as a cost-effective tracer for modelling of water age distributions and associated hydrological processes in karst catchments.

Association of meteorological variables with leaf spot and fruit rot disease incidence in eggplant and YOLOv8-based disease classification

Eggplant is one of the major vegetables consumed worldwide. Several fungal, bacterial, and viral diseases challenge the yield and quality of eggplant. The incidence of plant diseases is strongly influenced by weather factors such as temperature, humidity, rainfall, and wind speed. Mattu Gulla (MG) is a GI-tagged traditional variety of eggplant grown in Mattu village of the Udupi district in Karnataka state, India, with a cultural legacy of more than four centuries. In this study, we investigated the relationships between weather parameters and disease incidence in Mattu Gulla. Leaf spot (LS) and fruit rot (FR) are the major diseases affecting this plant variety. The influence of plant age and weather parameters on the modulation of the disease incidence (%) [DI (%)] of leaf spot and fruit rot was recorded and analyzed via correlation and regression. Prediction equations for disease incidence was derived via regression. A significant negative correlation was observed between the leaf spot DI (%) and minimum temperature (Min. temp), and a positive correlation was observed between the DI (%) and fruit rot. In the case of FR, the DI (%) is also significantly positively correlated with wind speed (WS), temperature, maximum relative humidity (RH I), rainfall (RF), and wind speed (WS). An RH I of 86–87 % was favorable for the incidence of fruit rot in the field. Regression analysis revealed a significant association between Min. temp and leaf spot DI (%), and in the case of fruit rot DI (%), the association was with Min. temp and WS. An android application, “Leaf Guard,” has been developed for AI-based disease detection in eggplant. During testing, the accuracy of the trained model reached 98.2 %.

Stability and heavy metals accumulation of soil aggregates under different land uses in the southwest coastal Bangladesh

Agricultural soil contamination is increasing day-by-day and becoming a major problem over the globe. Trace elements accumulation in the bulk soil is frequently documented, however, there is no precise mechanism of their distribution in the different soil aggregates level. We collected twelve composite soil samples from banana fields, fallow land, rice cultivated with pond water (rice field-I), and rice cultivated with rain water (rice field-II). We separated soil samples into four different size of aggregates (4-2, 2–0.25, 0.25–0.053, <0.053-mm) and then, aggregate stability (MWD), soil organic carbon (SOC), and heavy metals content (Pb, Cd, Cr, As, Fe, Mn, Zn, Ni, Co, Cu) in the soil samples were measured with different techniques. Results showed that MWD was higher in the rice-based land use, which was significantly contributed by SOC (p < 0.001). The concentration of Pb, As, Cd, Fe, and Mn were increased, while Cu and Zn concentration were reduced with increasing aggregate size (p < 0.05). In contrast, aggregate size did not influence on Ni and Co accumulation (p > 0.05). Moreover, macroaggregate acted as an accumulator for Fe, Mn, and As, while all the aggregate fractions acted as accumulators for Cu and Zn. Our study indicated that MWD, SOC, aggregate size and composition, and metal species were the controlling factors of trace elements accumulation and distribution in the various sizes of soil aggregates.

Monitoring of Fall Army Worm &lt;i&gt;Spodoptera frugiperda&lt;/i&gt; (J E Smith)

Study on monitoring of male moth fall army worm, Spodoptera frugiperda (J E Smith) was carried out in Agro-climatic zone-III at agricultural landscape of different farms of Anand Agricultural University, Anand during June 2020 to May 2022. A fifteen funnel shaped traps with lure for FAW were installed on border area and army-maize lure of Albero green organicz was suspended. The traps were arranged with at least 50 m distance between two traps which were spread over approximately 83 ha, Data from 104 standard meteorological week (SMW). Observation reveal that the counts ranged from 0.04 to 0.87 moths/trap/week from 24th SMW of 2020 to 23rd SMW of 2022. Higher numbers of non-target populations were captured in trap than the S. frugiperda. FAW moth catches/ week reported low positive correlation with bright sunshine hours (r=0.203) and very low positive correlation with maximum temperature (r=0.098); and markedly low negative correlation with evening relative humidity (r=-0.220), wind speed (r=-0.171) and rain fall (r=-0.126). It exhibited very low negative correlation with morning relative humidity (r=-0.048) and minimum temperature (r=-0.093).

Feasibility of Rooftop Rain Water Harvesting at Grey Iron Foundry, Jabalpur, Madhya Pradesh, India

Feasibility of Rooftop Rain Water Harvesting at Grey Iron Foundry, Jabalpur, Madhya Pradesh, India

Ecosystem services from rain water harvesting, agroforestry and livestock based smallholder rain-fed integrated farming system

Ecosystem services from rain water harvesting, agroforestry and livestock based smallholder rain-fed integrated farming system