Author(s)

Relwindé Abdoul-Karim Nassa¹, Amani Michel Kouassi², Makouin Louise Toure³

¹National Polytechnic Institute Félix Houphouët-Boigny (INP-HB), Polytechnic Doctoral School (EDP), Yamoussoukro, Ivory Coast.
²National Polytechnic Institute Félix Houphouët-Boigny (INP-HB), Department of Earth Sciences and Mineral Resources (STeRMi), Laboratory of Civil Engineering, Geosciences and Geographical Sciences, Yamoussoukro, Ivory Coast.
³National Polytechnic Institute Félix Houphouët-Boigny (INP-HB), Superior School of Mines and Geology (ESMG), Yamoussoukro, Ivory Coast.

The objective of this study is to analyze the sensitivity of the statistical models regarding the size of samples. The study carried out in Ivory Coast is based on annual maximum daily rainfall data collected from 26 stations. The methodological approach is based on the statistical modeling of maximum daily rainfall. Adjustments were made on several sample sizes and several return periods (2, 5, 10, 20, 50 and 100 years). The main results have shown that the 30 years series (1931-1960; 1961-1990; 1991-2020) are better adjusted by the Gumbel (26.92% - 53.85%) and Inverse Gamma (26.92% - 46.15%). Concerning the 60-years series (1931-1990; 1961-2020), they are better adjusted by the Inverse Gamma (30.77%), Gamma (15.38% - 46.15%) and Gumbel (15.38% - 42.31%). The full chronicle 1931-2020 (90 years) presents a notable supremacy of 50% of Gumbel model over the Gamma (34.62%) and Gamma Inverse (15.38%) model. It is noted that the Gumbel is the most dominant model overall and more particularly in wet periods. The data for periods with normal and dry trends were better fitted by Gamma and Inverse Gamma.

Sensitivity of Models, Sample Size, Statistical Models of Extremes, Ivory Coast

Nassa, R. , Kouassi, A. and Toure, M. (2021) Sensitivity of Statistical Models for Extremes Rainfall Adjustment Regarding Data Size: Case of Ivory Coast. Journal of Water Resource and Protection, 13, 654-674. doi: 10.4236/jwarp.2021.138035.