Version 1
: Received: 6 November 2023 / Approved: 7 November 2023 / Online: 8 November 2023 (01:30:02 CET)
How to cite:
Dioumacor, F.; Kaly, F.; Dieng, A.L.; Wane, D.; FALL, C.M.N.; Gaye, A.T. Prediction of the Onset and Offset of the Rainy Season in Senegal Using Kohonen Self-Organizing Maps. Preprints2023, 2023110448. https://doi.org/10.20944/preprints202311.0448.v1
Dioumacor, F.; Kaly, F.; Dieng, A.L.; Wane, D.; FALL, C.M.N.; Gaye, A.T. Prediction of the Onset and Offset of the Rainy Season in Senegal Using Kohonen Self-Organizing Maps. Preprints 2023, 2023110448. https://doi.org/10.20944/preprints202311.0448.v1
Dioumacor, F.; Kaly, F.; Dieng, A.L.; Wane, D.; FALL, C.M.N.; Gaye, A.T. Prediction of the Onset and Offset of the Rainy Season in Senegal Using Kohonen Self-Organizing Maps. Preprints2023, 2023110448. https://doi.org/10.20944/preprints202311.0448.v1
APA Style
Dioumacor, F., Kaly, F., Dieng, A.L., Wane, D., FALL, C.M.N., & Gaye, A.T. (2023). Prediction of the Onset and Offset of the Rainy Season in Senegal Using Kohonen Self-Organizing Maps. Preprints. https://doi.org/10.20944/preprints202311.0448.v1
Chicago/Turabian Style
Dioumacor, F., Cheikh Modou Noreyni FALL and Amadou Thierno Gaye. 2023 "Prediction of the Onset and Offset of the Rainy Season in Senegal Using Kohonen Self-Organizing Maps" Preprints. https://doi.org/10.20944/preprints202311.0448.v1
Abstract
This study investigates the spatio-temporal variability of the onset, offset, and Length of the rainy season in Senegal over the 1981-2018 period. The onset, offset dates, and length of the rainy season are crucial parameters for agricultural planning in West Africa, which exhibits high interannual and spatial variability in rainfall. The objective is to detect and spatially classify these phenological parameters across Senegal using different approaches. Daily precipitation data from the Climate Hazards group InfraRed Precipitation with Stations (CHIRPS) dataset over the study period and ERA5 reanalysis were used. The method of was applied to detect the onset, offset dates, and length of the rainy season. The Kohonen algorithm was then used to spatially classify these parameters on topological maps. A hierarchical ascendant classification was also performed to reduce the number of classes obtained. Finally, a composite analysis of moisture transport before the onset and end of the 1984 and 2007 seasons was conducted with ERA5 data. The results show a meridional gradient of the start of the season, progressively later from southeast to northwest, while the end follows a north-south gradient. The duration of the rainy season ranges from 45 days in northern Senegal to 150 days in the south. The maximum number of dry days also decreases from north to south. The Kohonen self-organizing maps allow spatial prediction of the onset, end date, and duration of the rainy season across Senegal. The dynamics analysis reveals that early onset years are associated with stronger and earlier northward moisture transport over West Africa, underscoring the role of this parameter in triggering the rainy season. These promising results can provide an early warning to policymakers and farmers on the start and end dates of the season in each area of Senegal.
Keywords
onset of the rainy season; offset of the rainy season; length of the rainy season; Kohonen 20 algorithm; hierarchical ascendant classification; Senegal; West Africa
Subject
Environmental and Earth Sciences, Atmospheric Science and Meteorology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
