Estimating and analyzing extreme daily rain greater than a equatorial climate threshold: the case of East-Cameroon

• Published in: Modeling earth systems and environment Vol. 8; no. 4; pp. 4497 - 4507
• Main Authors: Kalédjé, P. S. Kouassy, Noudja, T., Ngoupayou, J. R. Ndam, Rakotondrabe, F.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2022
• Subjects: Chemistry and Earth Sciences; Computer Science; Earth and Environmental Science; Earth Sciences; Earth System Sciences; Ecosystems; Environment; Math. Appl. in Environmental Science; Mathematical Applications in the Physical Sciences; Original Article; Physics; Statistics for Engineering; East-Cameroon; Parameters; Extreme rains; Generalized Pareto distribution; Rainfall quantiles; Above-threshold values
• ISSN: 2363-6203; 2363-6211
• DOI: 10.1007/s40808-022-01390-x

Extreme rains usually generate floods which cause important infrastructural damages. The estimation of extreme rains is, therefore, of paramount importance in anticipating disasters, such as floods, and thus allow a thoughtful development of the territory. This paper uses the values above a threshold approach to analyze, interpret and understand the probability distribution of the extreme rains that have recently generated many floods event in the Southeast of Cameroon. To do this, series of rainfall data recorded at 27 rainfall posts during the period 1948–2015 are analyzed. As result, statistical analyses show optimal thresholds for estimating extreme daily rainfall between 32 and 55 mm. The majority (74%) of the daily rainfall series exceeding a threshold are well adjusted by the Generalized Pareto Law. The uncertainty associated to the form parameter ( k ) appears to be very important and increases with the estimated threshold. In addition, spatial analysis of the centennials and decadal daily rains shows that the highest values of rain events are observed mainly on the Centre of the study area, between latitudes 4° 00ʹ and 5° 50ʹ North, and in the mountainous area of the catchment.