Significant Increase In Rainfall Research Articles

The assessment of groundwater reserves, quality, and balance in Quang Nam region, Vietnam: using MIKE BASIN and MODFLOW models

Abstract This comprehensive study examines the groundwater reserves and quality within the Quang Nam region, Vietnam, utilising the integrated MIKE BASIN and MODFLOW models. The research systematically analyses the coastal and key economic zones, covering 259,039 hectares, including urban and rural districts. The study delineates the region's hydrogeology, revealing a significant volume of groundwater reserves with a static water level, suggesting robust aquifer systems, particularly in the Dien Ban and Thang Binh districts. Furthermore, hydrogeochemical analysis assessed groundwater quality, indicating suitability for agriculture, which accounts for 81% of the region's water demand and other uses. The study's novelty lies in its dual approach of quantifying groundwater reserves and evaluating their quality, addressing a critical regional water resource management gap. The findings present an optimistic scenario for the current and future sustainability of water resources, with the calculated groundwater reserves demonstrating ample capacity to support the varied needs of the region. This research establishes a foundational understanding of Quang Nam's hydrological system. It provides strategic insights for sustainable water management in response to socio-economic development and climate change projections up to 2030. Climate projections for Quảng Nam province under RCP 4.5 and RCP 8.5 scenarios indicate significant increases in rainfall, temperature, sea level rise, and saltwater intrusion, highlighting the critical need for adaptive strategies to protect local ecosystems and communities from these escalating climate threats.

Long term (1901−2021) trends and prediction of climatic variability in selected agro‐ecological zones of Himachal Pradesh using coupled statistical and machine learning approaches

This study analyses the trends of changing climatic elements in the hydrological regime of the Indian Himalayan Region with specific focus on Agro‐ecological zone II & III of Himachal Pradesh for the period of 1901−2021. The upper, middle, and lower catchment areas of Sutlej River Basin were studied to reveal regional trends in climatic parameters. The Mann‐Kendall test and Sen Slope analysis were used to estimate annual and seasonal trends and their magnitude. The results showed a significant decreasing trend in the lower catchment area, with a break point year estimated to be 1953 for the entire basin. Two blocks of analysis, 1901−1953 and 1954−2021, showed significant variations. Annual rainfall data revealed a statistically significant decreasing trend at different stations. The lower catchment area received a significant increase in rainfall compared to higher altitude stations. In terms of seasonal variation, the pre‐monsoon season showed a significant decrease, while the entire basin recorded a significant increase in average monthly temperature. The study concludes by generating future time series predictions using an ANN model for the period of 2022−2050. Overall, the study's findings indicate a significant change in climatic variables with signs of increasing monthly temperatures and decreasing annual rainfall.

Trend Analysis of Rainfall and Detection of Change Point in Terai Zone of West Bengal

Analyzing rainfall trends is crucial for understanding climate patterns to managing water resources and planning agriculture. Trends in rainfall can reveal shifts in climate conditions, whether it is an increase, decrease, or fluctuate over time. The present study intends to examine the long-term trend in monthly, seasonal and annual rainfall in Cooch Behar district of West Bengal spanning from 1969 to 2022. Wallis and Moore test applied to determine the randomness of rainfall, whereas, linear regression trend line, Mann-Kendall (MK) test, Modified-Mann Kendall (MMK) test, and Innovative Trend Analysis (ITA) are used to understand the trend pattern in rainfall. MMK test reveals a significant decreasing trend in November month. In contrast, the remaining months, seasonal and annual rainfall revealed non-significant trend. According to the ITA approach, there was a significant increase in rainfall of January and a significant decrease in rainfall of November and December. The Pettitt’s test identified November 2006 as a trend changing year and there was no significant change point for the remaining months, seasonal and annual rainfall.

Hydrological changes in the drought‐prone region of Maharashtra (India): Implications for sustainable water use

Recent climatic changes and anthropogenic activities considerably affect regional water resources, particularly in water‐scarce regions. The present study, therefore, aims to understand the changes in monsoon rainfall, potential evapotranspiration (PET), surface runoff, dam storage and groundwater in the drought‐prone region of Maharashtra. The analyses of trend and step‐change were carried out using standard parametric tests. The results were verified with the application of non‐parametric statistical techniques. Notably, monsoon rainfall and runoff were observed to be declining. Exceptionally, the Yerala Basin witnessed significant increase in rainfall along with heavy rainfall events. Contradictorily, Agrani and Man Basins registered a notable decline in rainfall and runoff. As vulnerability to hydrological disasters is high, these basins should be carefully monitored. Although surface water harvesting brought a positive change in post‐monsoon groundwater level, it was the main reason for a decline in runoff volume at downstream reaches, which led to intra‐basin water disparity. The study area witnessed significant increase in groundwater extraction. Unfortunately, the misuse of government‐subsidized schemes exacerbates groundwater exploitation and stockpiling of water resources. Moreover, the increasing rate of PET augments hydrological losses and amplifies water distress. Interestingly, almost all the hydrological changes were notably experienced during the post‐2000 period. To cope with present and future water scarcity problems, it is therefore necessary to restrict irrational use and allocation of available limited water resources. The findings that emerge from this investigation may help to formulate judicious water policies and plans which could be implemented by the government, agronomists, water resource managers and farmers.

Research on the fugitive soil dust emission inventory in Western China based on wind erosion equation parameter optimization

The Wind Erosion Equation, currently one of the primary methods for estimating fugitive soil dust emission inventory, is influenced by several factors. Taking the convergent areas of the Tibet Plateau, Loess Plateau, and Qinba Mountains in Western China, we have optimized the climate factor using the WRF model driven by ERA5 reanalysis data. Additionally, we have modified the vegetation cover factors via normalized difference vegetation index and considered the impacts of the land use and cover change. Subsequently, other factors were allocated utilizing geographic information system, and the grid-based fugitive soil dust emission inventory for the study area for 2019 was derived through calculation. Based on the climate factor and vegetation cover factor, we have come up with the monthly allocation coefficients. The study has revealed the following findings: (1) Climate factors are unevenly distributed throughout the focused region, with the Loess Plateau showing the highest value, followed by the Tibet Plateau and the Qinba Mountains. There are also significant variations in the distribution of these factors among municipalities and counties; (2) The order of vegetation cover factor, primarily influenced by regional background as well as agricultural and pastoral activities, in the Loess Plateau, Tibetan Plateau and Qinba Mountains, is consistent with that of the wind erosion index; (3) In 2019, fugitive dust emissions from total suspended particles, PM10, and PM2.5 reached 9835.9, 2950.8, and 491.8 kt/a, respectively. The Loess Plateau exhibited the highest emission intensity due to factors such as low vegetation coverage, precipitation, high wind speed and wind erosion index; (4) Climate factor and vegetation cover factor are the primary factors influencing the monthly allocation coefficients. In 2019, the highest monthly fugitive dust emissions were estimated in April, accounting for approximately 36.21% of the total. The second and third-highest were found in August and June, respectively. This phenomenon can be explained climatically, as the Loess Plateau, semi-arid and arid regions, did not experience a significant increase in rainfall corresponding to rising temperatures.

Seasonal Effects on the Fecal Microbial Composition of Wild Greater Thick-Tailed Galagos (Otolemur crassicaudatus)

AbstractBacterial communities present in the host digestive tract are important for the breakdown and absorption of nutrients required by the host. Changes in diet and the environment are major factors affecting the composition and diversity of the fecal microbiome. In addition to changes in ambient temperature and rainfall, primates living in seasonal temperate environments also need to adapt to seasonal changes in food resource quantity and quality. However, there is a lack of information about the fecal microbiome in African strepsirrhines relative to other primate taxa. We examined the effects of seasonal dietary and environmental changes on fecal microbial alpha diversity and composition in wild greater thick-tailed galagos (Otolemur crassicaudatus) at Lajuma Research Centre, South Africa. We collected fecal samples and assessed food availability and weather in summer and winter across 1 year and used 16S rRNA next-generation sequencing to characterise the fecal microbiome of 49 animals. We found significant increases in rainfall, ambient temperature, and food availability in summer compared with winter. However, we found no significant changes in body mass or in the overall diversity of bacterial species present in fecal samples between the two seasons. We found significant decreases in the abundance of certain bacterial families in winter, suggesting a change in diet. Our findings suggest that greater thick-tailed galagos can find food resources to maintain their body mass throughout the year. Our insights into the seasonal fecal microbiome of greater thick-tailed galagos add to the growing knowledge and understanding of fecal microbiomes in primates and how they help primates cope with changes to their environments.

Assessment of Future Climate and Kharif Paddy Yields using Ceres-Rice in the State of Andhra Pradesh

Climate change considerably impacts water needs for agricultural production, particularly in paddy crops (Oryza Sativa). The paddy crop response is uncertain and also heterogeneous due to climate change. Climate variables rainfall and temperature directly impact crop productivity. A precise understanding of crop yields is required for agricultural production management to plan sustainable food demand in the future at the state level. The climate change scenario's impact on rice yield at 0.25° × 0.25° spatial resolution was assessed in Andhra Pradesh and presented in this paper. The use of representative concentration Pathway 8.5 scenario in projections made by the Global Climate Model (GCM) were downscaled for mid-century (2048-2078) using statistical tools. In this study, the Cropping System Model (CSM) and Crop Estimation through Resource and Environment Synthesis (CERES) modules for rice, as part of the Decision Support System for Agro-technology Transfer (DSSAT) package, were utilized. The use of the Regional Crop Yield Estimation System (RCYES) for the Cropping System Model (CSM) within the Decision Support System for Agro-technology Transfer (DSSAT) was facilitated through Python in this study. It is observed that rainfall will decrease during winter and pre-monsoon seasons related to the baseline period (1988–2018) for RCP 8.5. From July to October, there was a significant increase in rainfall. The most considerable change in the rain was 50.7 mm in September. A notable variation between the maximum and minimum temperatures of 2.3 and 2.5 degrees Celsius in June and April respectively. Rainfall is expected to increase in Anantapur, Kurnool and Nellore districts during the mid-century 2040's. The correlation between the baseline and DES mean yield was 0.87, with a maximum yield of 0.86 and a minimum yield of 0.82. Decrease paddy yields by up to 10.7% in West Godavari, Krishna, Guntur, Nellore and Prakasam districts. At the same time, an increase in paddy yields up to 9.8% is anticipated in Srikakulam, Visakhapatnam, Vizianagaram, East Godavari, Anantapur, Chittoor, Kadapa, and Kurnool. In contrast, a maximum decrease of 189.9 mm of rainfall is expected in the Vizianagaram district. These results could assist in devising adaptation measures to reduce the negative effect of climate change on rice crops in Andhra Pradesh.

About the possibility of natural emergency risk management in mountain areas by thermal impact on the surface troposphere layer

A pressing issue in managing the risks of wildfires in mountain regions of the world is improving the management of rainfall intensity over their territories. The relative humidity of the air in which precipitation should be initiated is an important factor in the effectiveness of such techniques. In mountains, forced convection on windward slopes has led to a significant increase in rainfall. At the same time, the humidity of the air entering the downwind slopes is reduced, thus increasing the fire risk on them. It has been hypothesized that it is possible to increase the humidity of the air entering the leeward slopes of the mountains by initiating thermal convection on their windward slopes. Its fairness is confirmed by the model of mountain mossiv with parameters corresponding to the southern slope of the Ai-Petra Yayla (Main Ridge of the Crimean Mountains). The weather conditions characteristic of this area during the summer months were considered. The method of the study consisted in numerically solving complete nonlinear thermometer equations using Fire Dinamic Simulator (FDS) programs. It has been established that excitation of thermal convection on a local part of the windward slope of the mountains can cause a significant increase in the height of the dew point above the whole of this slope, which the advanced hypothesis confirms. The results show that it is possible to apply the methodology considered for the suppression of forest and other natural fires on leeward slopes of mountains.

“BANJIR DAN BANTUAN DI SURAKARTA” FILANTROPI DALAM BANJIR SOLO TAHUN 1966

ABSTRACT This research discussed aboute the philanthropic practices that occurred in the Solo flood in 1966. The city of Solo and the surrounding area is an area that is often subject to flooding. This happens because Solo City is one of the areas crossed by the Bengawan Solo River, where Bengawan Solo is the longest river in Java Island. If at any time there is a significant increase in rainfall and for a long time, the worst risk caused is the occurrence of a flood disaster. One of the major floods that hit Solo City and the surrounding area was the flash flood that occurred in 1966. The incident hit six inner districts and caused considerable losses. The problem studied this time is how the philanthropic practices of the Indonesian people remain intertwined in the midst of unstable political conditions, because 1966 was a fairly crucial period. To conduct this research, the author used the historical research method. This method includes the selection of titles, data collection, criticism or selection and filtering of data, interpretation or interpretation of the data that has been obtained, and the last step is historiography or the stage of writing history. In addition to using historical research methods, the author also uses the concept of social roles as a theoretical basis in carrying out the research. The concept was chosen by the author because it is able to help the author in seeing how the role of each individual and group in the recovery of the Solo City Area and its surroundings after the flash flood disaster. The results of this reseach is explain how the flood disaster that hit the Solo region and its surroundings in 1966 could move a sense of humanity and empathy among the Indonesian people in the midst of unstable political conditions. Until the people of Solo City and also the surrounding areas who are victims of the disaster can bounce back from the slump caused by the flood disaster. The participation of the Indonesian people as a reaction to the flood event that hit Solo and its surroundings was able to restore the state of Solo City and the surrounding area as before. Keywords: Bengawan Solo, flood, philanthropy

Rainfall Variability and Trends over the African Continent Using TAMSAT Data (1983–2020): Towards Climate Change Resilience and Adaptation

This study reveals rainfall variability and trends in the African continent using TAMSAT data from 1983 to 2020. In the study, a Mann–Kendall (MK) test and Sen’s slope estimator were used to analyze rainfall trends and their magnitude, respectively, under monthly, seasonal, and annual timeframes as an indication of climate change using different natural and geographical contexts (i.e., sub-regions, climate zones, major river basins, and countries). The study finds that the highest annual rainfall trends were recorded in Rwanda (11.97 mm/year), the Gulf of Guinea (river basin 8.71 mm/year), the tropical rainforest climate zone (8.21 mm/year), and the Central African region (6.84 mm/year), while Mozambique (−0.437 mm/year), the subtropical northern desert (0.80 mm/year), the west coast river basin of South Africa (−0.360 mm/year), and the Northern Africa region (1.07 mm/year) show the lowest annual rainfall trends. There is a statistically significant increase in the rainfall in the countries of Africa’s northern and central regions, while there is no statistically significant change in the countries of the southern and eastern regions. In terms of climate zones, in the tropical northern desert climates, tropical northern peninsulas, and tropical grasslands, there is a significant increase in rainfall over the entire timeframe of the month, season, and year. This implies that increased rainfall will have a positive effect on the food security of the countries in those climatic zones. Since a large percentage of Africa’s agriculture is based only on rainfall (i.e., rain-fed agriculture), increasing trends in rainfall can assist climate resilience and adaptation, while declining rainfall trends can badly affect it. This information can be crucial for decision-makers concerned with effective crop planning and water resource management. The rainfall variability and trend analysis of this study provide important information to decision-makers that need to effectively mitigate drought and flood risk.

Vulnerability of urban floods in association with the sewage system and geographical features in the Giulești – Sârbi neighborhood, Bucharest, Romania

The study aims to analyze the vulnerability of floods and their impact in the Giulești-Sârbi area, the marginal northwestern neighborhood of Bucharest. The location of the accumulation lake has hydrological importance for the studied area. The anthropogenic dam is one of the susceptible sources of floods, but the most inefficiency of the sewage system is the actual principal cause, which frequently flows back when there are significant increases in rainfall. The motivation for choosing the study is represented by the vulnerability of the Giulești-Sârbi area and by the lack of a study on flood vulnerability and frequency in the area. A questionnaire was also applied locally, some of the results being presented in this paper. The main objectives of the study refer to the spatialization at the street level of the vulnerability of floods and their following impact. It also compares the vulnerability of floods after two key periods: before and after the construction of the dam, respectively 1980 and 2020 – for the comparison and evolution of terrain changes. The problem was also analyzed by the vulnerability related to the slope, land use and geological characteristics. The results show that the Giulești-Sârbi neighborhood is still susceptible to floods. The most affected streets are those from the southeastern part of the neighborhood and punctually to the NW. On the other hand, the application of the questionnaire shows that the southernmost street (Răsadniței Street) did not register problems as often as the current hazard maps from the rowater.ro source for which the highest vulnerability was expected to show. The areas indicating problems according to the questionnaires and Romanian Waters National Administration maps largely coincide with the results of the vulnerability maps resulting in this paper. The main solution that can reduce the effect of flood vulnerability is the modernization of the sewage system.

Rainfall in Brazilian Northeast via in situ data and CHELSA product: mapping, trends, and socio-environmental implications.

Rainfall is a climatic variable that dictates the daily rhythm of urban areas in Northeastern Brazil (NEB) and, therefore, understanding its dynamics is fundamental. The objectives of the study were (i) to validate the CHELSA product with data in situ, (ii) assess the spatial-temporality of the rains, and (iii) assess the trends and socio-environmental implications in the Metropolitan Region of Maceió (MRM). The monthly rainfall data observed between 1960 and 2016 were flawed and were filled with the imputation of data. These series were subjected to descriptive and exploratory statistics, statistical indicators, and the Mann-Kendall (MK) and Pettitt tests. CHELSA product was validated for MRM, and all stations obtained satisfactory determination coefficients (R2) and Pearson correlation (r). The standard error of the estimate (SEE), root mean square error (RMSE), and mean absolute error (MAE) were satisfactory. The highest annual rainfall accumulated occurred near the Mundaú and Manguaba lagoons. The Pettitt test identified that abrupt changes occur in El Niño and La Niña years (strong and weak). The monthly rain boxplots showed high variability in the rainy season (April-July). Outliers have been associated with extreme rainfall at MRM. The drought period was 5 months in all MRM seasons, except in Satuba and Pilar. The Mann-Kendall test and the Sen method showed a tendency for a significant increase in rainfall in Satuba and not significant in the Pilar, while in the others, there was a tendency for a decrease in rainfall. The MRM rainfall depends on physiographic factors, multiscale meteorological systems, and the coastal environment. These results will assist in planning conservationist practices, especially in areas of socio-environmental vulnerability.

Spatio-temporal analysis of rainfall pattern in the Western Ghats region of India

This paper investigates the rainfall pattern and its distribution, which is one of the key drivers for the water availability in the Western Ghats region of India. The daily precipitation data from 1901 to 2014 were investigated to understand the rainfall pattern and its variability. The study area has been divided as southern, coastal, central, and northern regions and rainfall amount into 0.2–10 mm, 10–20 mm, and > 50 mm classes. The trends in the annual rainfall, number of rainy days, and various classes within these regions have been investigated. The mean annual rainfall varies between 4000 mm in the coastal areas and greater than 6000 mm at the mountain crest. The Mann–Kendall test indicates significant decrease of annual rainfall, at 5% significance level in central and coastal region. On Contrary, the coastal region recorded significant decrease in the number of rainy days at 5% significance level. An increasing trend in the number of rainy days has been observed in the northern region. No significant trends have been detected in the southern region. A decreasing trend has been detected in the number of rainy days in the rainfall class with 10–20 mm in coastal region. Similarly a significant decrease of rainy days was observed in > 50 mm rainfall class both in the southern and northern regions. The change point probability and homogeneity test indicates that there is a significant increase in rainfall in few stations under the northern region and similarly decrease in the rainfall in central region during the decade of 1970 and normally the rainfall has been homogeneous in the study area. From the precipitation concentration analysis found that Mysore, Kodagu, and adjoining areas are influenced by the bi-modal rainfall, receiving the rainfall during both south–west and north–east monsoons. This analysis helps to understand the spatial variability of rainfall in the Western Ghats of India, which depict mixed trends in the quantum of rainfall and decreasing trend of rainy days across various rainfall classes. These changes detected in the historical rainfall, both in its occurrence and quantum will have significant bearing on the water availability scenario in the Western Ghats region.

Future Climate Change Scenario over Maharashtra, Western India: Implications of the Regional Climate Model (REMO-2009) for the Understanding of Agricultural Vulnerability

The present investigation attempts to understand the near-term (up to 2050) and distant (up to 2100) future climatic changes over Maharashtra. Trend analysis of projected monsoon rainfall and temperature was carried out with the use of parametric and non-parametric statistical techniques. All the meteorological sub-divisions in Maharashtra reveal a significant increase in monsoon rainfall during 2015–2100 (by 150–210 mm), except Konkan. In a near-term future, parts of the Vidarbha Sub-division and Western Ghats exhibit a significant increase in rainfall by 82–225 mm. Almost the entire state is very likely to experience a rise in annual mean temperature (AMT) by 0.5–2.5 °C up to 2050. The state is very likely to experience considerably warmer conditions post-2033. In particular, parts of Konkan and Madhya Maharashtra Sub-divisions will register significant warming (by 1–2.5 °C). The estimations also signify a marginal increase in AMT during the post-2070 period. The annual maximum temperature (AMXT) does not show a considerable rise; however, the annual minimum temperature (AMNT) is expected to increase (by < 1.2 °C) significantly over about 80% of the districts in Maharashtra. These climatic changes are very likely to affect the productivity of principal crops in Maharashtra including sorghum, pearl millet, sugarcane, wheat, rice and cotton. Under the future climate change scenario, therefore, it will be a great challenge for agronomist and policymakers to formulate a judicial plan for sustainable agriculture.

Identificação das causas climáticas dos eventos extremos e dos impactos dos ENOS Canônico e Modoki nas macrorregiões de Alagoas

O objetivo desse trabalho é identificar as causas climáticas dos eventos extremos ocorridos nas macrorregiões de Alagoas, e ao mesmo tempo, comparar os efeitos dos ENOS Canônico e Modoki e suas classes sobre as macrorregiões alagoanas. Os dados de precipitação diária de 21 municípios do Estado de Alagoas foram obtidos através da Agência Nacional de Águas com período de 1963 a 2014. EN Modoki e Fracos promoveram aumento de chuvas na região Leste. Já EN Fortes causaram diminuição de precipitação no Sertão. Eventos de LN Canônica causaram aumento significativo nas chuvas das 3 macrorregiões, mas o efeito foi melhor em LN Forte. Durante as fases do Dipólo do Atlântico, a fase negativa gerou SPI positivo em todo estado, e na fase positiva, houve diminuição do SPI na região Leste, e registro de SPI negativo no Sertão e Agreste. As causas climáticas dos eventos extremos foi a junção das escalas semestral, interanual, escala entre 1-2 anos de ENOS, escala de ENOS estendido e escala de 11 anos (Dipólo e Manchas solares) potencializando os totais pluviométricos locais, e para casos de seca, sua ausência. Verificou-se, através de análises de agrupamentos, semelhança entre os SPIs da La Niña Fraca e La Niña Canônica, e entre o El Niño Canônico está ligado ao El Niño Forte. Já matematicamente, as categorias de El Niño e La Niña forte e fraca apresentaram melhores correlações com ENOS Modoki e Canônico, sugerindo padrão para Alagoas. Identification of climatic causes of extreme events and impacts of Canonical and Modoki ENSO on Alagoas macroregions. A B S T R A C TAnomalies of sea surface temperature that occur in some regions of the Equatorial Pacific Ocean are being studied because their cause different impacts and originate in different ways, are the ENOS, Modoki and Canonical.The objective of this work is to identify the climatic causes of the extreme events that occurred in the macro-regions of Alagoas, and at the same time, to compare the effects of ENOS Canonical and Modoki and their classes on the macro-regions of Alagoas. The daily precipitation data for 21 municipalities in the State of Alagoas were obtained through the National Water Agency from 1963 to 2014. EN Modoki and low promoted an increase in rainfall in the Eastern region. EN Fortes, on the other hand, caused a decrease in rainfall in the Sertão. Canonical LN events caused a significant increase in rainfall in the three macro-regions, but the effect was better in LN Forte. During the phases of the Atlantic Dipole, the negative phase generated positive SPI across the state, and in the positive phase, there was a decrease in SPI in the East, and a negative SPI record in Sertão and Agreste. The climatic causes of the extreme events were the combination of semiannual, interannual scales, scale between 1-2 years of ENOS, scale of ENOS extended and scale of 11 years (Dipole and sunspots), potentiating the local total rainfall, and for cases of drought , your absence. It was found, through cluster analysis, similarity between the SPIs of La Niña low and La Niña Canonical, and between El Niño Canonical is linked to El Niño Forte. Mathematically, the categories of El Niño and La Niña strong and weak showed better correlations with ENOS Modoki and Canonical, suggesting a pattern for Alagoas.Keywords. Wavelet analysis; SPI; Cluster analysis.

The blessing of the “year without summer”: Climatic and socioeconomic impact of the Krakatoa eruption (1883) in the south‐east of the Iberian Peninsula

AbstractIn the current context of climate change–induced warming, interest in analysing the impact of volcanic eruptions on the climate has renewed. The main conclusions from related papers indicate that volcanic eruptions alter the terrestrial radiative balance and cause cooling in the years after an eruption: known as “years without summer.” These episodes of cyclical cooling have been related to negative socio‐economic impacts (such as crop reduction, famine, and social unrest). However, the effect on precipitation has been studied less. Detailed studies on the economic impact of large eruptions are scarce, especially for historical eruptions. This study analysed the effects of the 1883 Krakatoa eruption on temperature and precipitation in the south‐east of the Iberian Peninsula and related economic and social effects. It was concluded that this eruption incited a significant decrease in maximum temperatures and stability, an increase in minimum temperatures, a decrease in average temperatures, and a significant increase in rainfall. This climatic context produced a decrease in cereal prices and a reduction in climatic risks (droughts and frosts). Therefore, the effects of the eruption of Krakatoa improved socioeconomic conditions in the south‐eastern Iberian Peninsula.

Influence of Rainfall Intensity on the Stability of Unsaturated Soil Slope: Case Study of R523 Road in Thulamela Municipality, Limpopo Province, South Africa

The purpose of this paper was to analyze the impact of extreme rainfall on the recurrence of slope instability using the Thulamela Municipality roads (R523) as a case study. To this end, the historical rainfall data of the area of study were analyzed between 1988 and 2018. The results show that a significant increase in rainfall is usually experienced in the summer months of December and January. Following this, the factor of safety (FoS) of slopes of silt clay, clay, and clay loam soils were estimated using the SLIDE simulator (Numerical software “Finite Element Method (FEM)”) under sunny to rainy conditions of the area. A complementary model, FLACSlope (Numerical software “Finite Difference Method (FDM)”), was utilized to simulate FoS and pore water pressure in sunny and rainy conditions of the area. Simulation results show that extreme rainfall has the ability to reduce the shear strength and resistance of the soil slope material. This may explain the recurrent landslides noted in the area. Finally, the water pore pressure has been simulated to increase with the increased water table, which generally pushes the soil particles apart and reduces the stress between the particles resulting in soil slope failure. Extreme rainfall alters the phase of the material solid in a manner that may require further research for a better understanding.

Impact of Urbanization on Heavy Rainfall Events: A Case Study over the Megacity of Bengaluru, India

This study is about the simulation and observational analysis of a heavy rainfall event (HRE) and its sensitivity to land-use changes. The impact of urbanization on processes and mechanisms of rainfall including cloud processes is discussed. This study is based on high-resolution (2 km), time-ensemble simulation of one of the HREs that occurred on 27 May 2017 over the city of Bengaluru in the southern part of India. The simulations are carried out using the Weather Research and Forecasting (WRF) model, which is coupled with a single-layer urban canopy model (UCM). The high-resolution (30 s) land-use data derived from the Indian Space Research Organization (ISRO) for the year 2016–2017 is shown to be realistic in representing the current land-use scenario with a threefold increase in urbanization when compared to USGS land-use data of 1991–1992. Simulation and analysis of large-scale circulation patterns revealed that the event was triggered and sustained by the low-pressure system and cyclonic circulation over the Bay of Bengal. Simulated rainfall was found to be remarkably sensitive to land-use changes as shown by control (USGS) and test (ISRO) simulations. The rainfall intensity and spatial distribution are close to observation in test simulations with relatively less error at station scale with a correlation of 0.49 (95% significance) when compared to control simulations, indicating the importance of realistic representation of land use in the model and its impact on heavy rainfall processes. The test simulation which represents the current urbanization scenario has shown a significant increase in rainfall by over 100–200%. The surface energy fluxes and thermodynamic indices as shown by test simulations are favorable to HREs, and also consistent with the current land-use scenario with increased urbanization. This study demonstrated how a realistic representation of land-use data in the model can help to improve model skill. The main limitation of this research work is that it is based on the generic parameterization of urbanization using single-layer UCM. An in-depth study based on multi-layer UCM and city-specific parameterization of urbanization using sub-kilometer-scale land-use data including buildings would further enhance our understanding on this subject.

Is urbanisation also the culprit of climate change? – Evidence from Australian cities

In this study, daily maximum and minimum air temperature (Tmax and Tmin), evaporation and rainfall data (1960–2011 period) were analysed for three Australian metropolitan cities, viz., Sydney, Melbourne and Brisbane, to understand whether urbanisation has influenced temperature, evaporation and rainfall in these cities and thus had an influence on the longer-term local climate variability. A total of nine key locations in each city were considered and one location in each city was a control. A modified segmented regression analysis was employed to understand the overall climate change and linear regression analysis to evaluate the impacts of urbanisation.The study indicates a significant overall climate change during the 1986–2011 period when compared with the 1960–1985 periods, and urbanisation added to the overall climate change. There were statistically significant increases in Tmax and Tmin for Sydney and decreases for Melbourne, decrease in Tmax and increase in Tmin for Brisbane. On the other hand, evaporation values decreased for Sydney and Brisbane but increased for Melbourne. There was a statistically significant increase in rainfall for Brisbane only. The study suggests that climate change adaptation strategies and policies need to consider urbanisation, alongwith greenhouse gases, to cope with future climate change scenarios.

Small-scale fishers’ perceptions of climate change and its consequences on fisheries: the case of Sanyathi fishing basin, Lake Kariba, Zimbabwe

Small-scale fisheries, especially in developing countries, are susceptible to the negative impacts of climate change. Changing climate is one of the factors altering fish productivity, resulting in declining fish catches. Studies have been done to investigate the nature and extent of these impacts. However, research indicates that fishers in developing countries are unaware of the climate change phenomena. Therefore, it is crucial to understand how small-scale fishers perceive climate change at a local level. This study presents small-scale fishers’ perceptions of climate change and further elucidates on the impacts of climate change on fish production in Sanyathi fishing basin, Lake Kariba, Zimbabwe. Mixed method research approaches were employed in the study. Semi-structured questionnaires were administered to 66 fishers. Meteorological time series data were used to triangulate the fishers’ perceptions of climate change. Cross-tabulations (chi-square tests) and descriptive statistics were used to analyse the data. Results indicated that 92% of the fishers are aware of climate change. There is a significant (p < 0.05) categorical variable association between climate change perceptions and fish catches. However, there are no statistically significant (R2 = 0.08, p > 0.05, n = 30) changes in mean annual temperature from 1987 to 2016. There is a statistically significant increase in rainfall (R2 = 0.14, p < 0.05, n = 30) over the three decades. The results suggest that it is crucial for policy and development agencies to consider the fishers’ perceptions of climate change to formulate appropriate climate responses at the local level.