Applications of Innovative Polygon Trend Analysis and Trend Polygon Star Concept Methods for the Variability of Precipitation at Synoptic Stations in Benin (West Africa)

Climate variability poses new risks and uncertainties. In the sub-Saharan region, the impacts are already being felt and represent an additional level of obstacles for most vulnerable people, as well as a threat to sustainable development. This study analyzes the variability of precipitation in Benin using new approaches. The precipitation data used is the monthly average recorded at synoptic stations from 1970 to 2019 by the Metéo-Bénin agency. Two innovative graphical trend methods, innovative polygon trend analysis (IPTA) and trend polygon star concept (TPSC), are applied to the data. Both methods allow for the assessment of periodic characteristics of the monthly average rainfall and visually interpreting the transition trends between two consecutive months. The results show that the average monthly precipitation does not follow a regular pattern. There is also a general upward trend in precipitation for most months at the stations used. Most TPSC arrows were found in regions I and III. According to the TPSC graphs, the longest transition arrows between two consecutive months were observed in quadrant III. They were noted between the months of June and July in Cotonou, October and November in Bohicon and Save, and between September and October for the remaining stations. The results of this study are of great importance for policies regarding ongoing climate change in the agricultural, health, economic, security, and environmental sectors.