Rainfall in the Urban Area and Its Impact on Climatology and Population Growth

Abstract

Due to the scarcity of studies linking the variability of rainfall and population growth in the capital cities of Northeastern Brazil (NEB), the purpose of this study is to evaluate the variability and multiscale interaction (annual and seasonal), and in addition, to detect their trends and the impact of urban growth. For this, monthly rainfall data between 1960 and 2020 were used. In addition, the detection of rainfall trends on annual and seasonal scales was performed using the Mann–Kendall (MK) test and compared with the phases of El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). The relationship between population growth data and rainfall data for different decades was established. Results indicate that the variability of multiscale urban rainfall is directly associated with the ENSO and PDO phases, followed by the performance of rain-producing meteorological systems in the NEB. In addition, the anthropic influence is shown in the relational pattern between population growth and the variability of decennial rainfall in the capitals of the NEB. However, no capital showed a significant trend of increasing annual rainfall (as in the case of Aracaju, Maceió, and Salvador). The observed population increase in the last decades in the capitals of the NEB and the notable decreasing trend of rainfall could compromise the region’s water security. Moreover, if there is no strategic planning about water bodies, these changes in the rainfall pattern could be compromising.

Long‐term trend analysis in annual, seasonal and monthly rainfall in East Northeast of Brazil and the influence of modes of climate variability

“…Although some correlations indicate possible influences of PDO, SOI, ENSO and AMO at the breaking points, some trends did not show evidence of these influences. Changes in monthly rainfall may be partially due to natural climate variability, but may also be related to global warming and/or urbanization and changes in land use and occupation, as noted by Marengo et al (2020) for rainfall extremes in the Metropolitan Region of São Paulo (RMSP), Cecílio et al (2021) for the State of Espírito Santo and recently by Monteiro et al (2022) for Brazilian capitals and da Silva et al (2022) for NEB capitals. These studies highlighted the relationship between rainfall extremes and population growth in recent decades.…”

Effects of extreme phases of El Niño–Southern Oscillation on rainfall extremes in Alagoas, Brazil

“…For the cities of Rio Largo and Satuba, are both influenced by physiographic factors (Oliveira‐Júnior et al, 2021a, 2021b) and local meteorological systems (Gois et al, 2005; Souza et al, 2021). It is worth noting that the highlighted maximum and minimum values in both climatic mesoregions are due to the influence of sea breezes, Easterly Wave Disturbance (EWD), Trade Wave Disturbances (TWD), Vortex Cyclones of High Levels (VCHL) and convective rainfall due to urbanization (Monteiro et al, 2022; Oliveira‐Júnior et al, 2021a, 2021b; Santos et al, 2021), as well as all the multiscale systems together with the physiography that contribute to the rainfall gradient between the coast and the interior of the state (Costa et al, 2021; Lyra et al, 2014).…”

“…However, from the 2000s onwards, the outliers correspond to extreme droughts that affected the entire Northeast Brazil (NEB) region (Brito et al, 2018; Santos et al, 2019). Changes in the annual rainfall regime are directly related to ENSO events associated with multiscale meteorological systems (Costa et al, 2021; Lyra et al, 2014, 2017; Santos Rocha et al, 2022), local physiographic characteristics (Costa et al, 2020a, 2020b; Gois et al, 2005; Lima et al, 2019; Souza et al, 2021), and more recently, changes in land use and land cover, especially in the categories of agriculture and urbanization in the East part of the state (Monteiro et al, 2022; Oliveira‐Júnior et al, 2021a, 2021b; Santos et al, 2021).…”

“…It is worth noting that the NEB exhibits natural climatic variability associated with large-scale anomalous patterns, mainly influenced by climate variability modes such as El Niño-Southern Oscillation (ENSO), Madden-Julian Oscillation (MJO) (Kane, 1997;Marengo et al, 2017;Silva et al, 2020;Da Silva et al, 2021), the Interhemispheric Gradient of Sea Surface Temperature of the Atlantic (IGSSTA), formerly known as the Atlantic Dipole (Lyra et al, 2017;Oliveira-Júnior et al, 2021a, 2021b, and the Pacific Decadal Oscillation (PDO), which can decrease or enhance extreme events in the region, particularly in the East NEB (ENEB) (Lyra et al, 2014(Lyra et al, , 2017. The NEB is the region in the country with a high long-term climate risk concerning the population of the semiarid region (rainfall deficit) and, in recent decades, the population residing in metropolitan areas (extreme rainfall), and consequently, these are areas that also suffer from flash floods, landslides, urban drainage problems and waterborne diseases (Correia Filho et al, 2013;Costa et al, 2015;Marengo et al, 2020;Monteiro et al, 2022;Oliveira et al, 2013;Oliveira-Júnior et al, 2021a, 2021bSantos et al, 2023).…”

Prediction of flash flood susceptibility using integrating analytic hierarchy process (AHP) and frequency ratio (FR) algorithms

“…Different countries of the world are still more prone to the hazards of flash floods because of the changes in climatic conditions of the world (Das, 2019;Tariq et al, 2022e;Tariq and Mumtaz, 2022). The havoc of flash floods has been greater in those parts of the world that have not developed a system of forecast and flood effects mitigation (Kheradmand et al, 2018;Basharat et al, 2022;da Silva Monteiro et al, 2022). To avoid mass movement and reduce the aftermaths, it is crucial to develop a mapping system based on different parameters of cause and effects (Basin, 2021;Islam F. et al, 2022;Sharifi et al, 2022a;Hussain et al, 2022b).…”