Assessing the Return Periods and Hydroclimatic Parameters for Rainwater Drainage in the Coastal City of Cotonou in Benin under Climate Variability

Table 3

Parameters of Gumbel’s law derived from the method of moments and the graphical method.

Rainfall duration (hour)	Method of moments		Graphical method
	a	b	a	b	Coefficient of determination (R^2)
1	56.04	12.92	56.12	13.10	0.967
2	35.24	9.01	35.26	9.20	0.980
3	24.68	7.46	24.73	7.56	0.966
6	13.34	4.24	13.37	4.29	0.965
12	7.19	2.16	7.19	2.20	0.977
24	3.78	1.06	3.79	1.07	0.965