Multi-index detection of rainfall trends and climate shifts in urban tropical kinshasa (1991–2023)

Kinshasa, the capital of the Democratic Republic of Congo, is increasingly vulnerable to climate-induced rainfall extremes that threaten urban resilience. This study analyzes daily precipitation data over a 33-year period (1991–2023) using a suite of rainfall indices, including those developed by the Expert Team on Climate Change Detection and Indices (ETCCDI), alongside the Mann-Kendall trend test, to assess changes in rainfall intensity, frequency, duration, and extremes. Among the examined indices, Extremely Wet Days (EWD) and the Simple Daily Intensity Index (SDII) exhibited statistically significant positive trends. EWD showed a marked increase (Z = 2.657, p = 0.007), peaking at 15 days in 2020, the highest in the record, indicating a growing frequency of intense rainfall events. SDII also showed a significant rise (Z = 2.866, p = 0.004), suggesting intensification in daily rainfall amounts. Although the upward trend in annual total rainfall (PRCPTOT) was not statistically significant, it supports the overall pattern of increasing wetness. These findings underscore a rising risk of flash flooding and highlight the urgent need for adaptive water management strategies, early warning systems, and climate-resilient infrastructure planning in Kinshasa. The study provides vital evidence to inform policy and urban planning across tropical African cities.