Análise da variabilidade espacial e temporal da precipitação na cidade de Salvador

Abstract

This study examined the spatial and temporal distribution of rainfall in Salvador, Bahia, from 2016 to 2023, to identify seasonal patterns and regional differences. Daily rainfall records from 10 stations strategically distributed across different sectors of the Bahian capital were used. Data processing involved two-factor analysis of variance (Season × Month) using the Scott Knott cluster test, complemented by temporal analysis of historical data and the construction of isohyet maps to illustrate rainfall variations. The results demonstrated a very pronounced seasonality, highlighting the concentration of the rainy season between March and July, with maximum values recorded in April and May (272 mm and 253 mm, respectively). This behavior is due to the intensification of the Intertropical Convergence Zone (ITCZ) and the influence of the Eastern Wave Disturbances (EWDs). Statistically significant spatial heterogeneity was also observed (p<0.05), in which higher altitude coastal areas presented higher average rainfall totals (1,650 mm/year) when compared to the more urbanized inland regions (1,200 mm/year). Interseasonal variability reached 312 mm per year, clearly reflecting the influence of orographic relief associated with proximity to the ocean. These findings confirm previous studies on the topographic influence and maritime proximity on rainfall dynamics in urban environments, emphasizing the need to establish a continuous monitoring system that can adequately support urban planning and risk man agement actions in the city of Salvador-BA.