benny019/assessment-of-the-changes-in-Little-Dry-Season-characteristics-across-southwestern-nigeria

A research project repository built on a previous work for assessing trends in the Little Dry Season (LDS) characteristics in Southwestern Nigeria in correlation with changes in gulf of guinea SST. Includes analysis of onset, cessation, duration, rainfall amount, rain days, and intensity of LDS using a 40-year daily rainfall (CHIRPS) data. # Assessment of the Changing Characteristics of the Little Dry Season across Southwestern Nigeria in Relation to Gulf of Guinea Sea Surface Temperature # Abstract The Little Dry Season (LDS) is a defining feature of the rainfall regime in southwestern Nigeria, yet evidence of its recent evolution remains limited. This study assessed changes in LDS characteristics using 40 years (1985–2024) of CHIRPS daily rainfall data and investigated their relationship with Gulf of Guinea sea surface temperature (SST) from NOAA OISST v2.1. Results show that while LDS timing has remained relatively stable, rainfall characteristics have changed substantially, with declining rainfall totals, fewer rain days, and increasingly concentrated rainfall events. The Gulf of Guinea also exhibited a persistent warming trend, with weak-to-moderate relationships between SST variability and several LDS characteristics, particularly rainfall distribution and cessation. These findings improve understanding of evolving rainfall dynamics in southwestern Nigeria and provide insights relevant to climate adaptation and agricultural planning. ## Background The **Little Dry Season (LDS)** is a short-lived reduction in rainfall that occurs during the peak of the rainy season across southwestern Nigeria, typically between **mid-July and mid-August**. Despite its brief duration, it plays an important role in agriculture, water resource management, and ecosystem functioning. Farmers have traditionally relied on this seasonal break for activities such as weeding, fertilizer application, and harvesting, while the characteristics of the LDS have also been linked to the yield of important crops such as yam. Over recent decades, however, the timing and behaviour of the LDS have become increasingly variable. Reports of delayed onset, prolonged duration, false seasonal breaks, and changing rainfall characteristics suggest that the phenomenon is responding to broader climatic changes. Such changes increase uncert …