Abstract :
A real calamity for the design engineer of hydraulic structures when calculating annual daily maximum frequency precipitations, the north-central region of Algeria includes urban areas of great strategic importance such as Algiers (the capital). The estimation annual daily maximum frequency precipitations in this area from series of observations with little or no data, becomes unreliable. A regional frequency analysis emerged as one of the methods to resolve this problem. The L-moments method was applied to the annual daily maximum precipitations from fifty four rainfall stations in northern Algeria. This study permitted dividing this area into three statistically homogeneous regions. The Generalized Extreme Value (GEV) distribution and the Generalized Logistics (GLO) distribution were identified as the most appropriate regional distributions for modeling precipitation. In this study, they were used to calculate the regional quantiles for each region. For the above mentioned three regions, the values of roots mean square error between quantiles were below 8% for all return periods, an indication that the method used was appropriate.
Keyword :
annual maximum daily precipitations, regional frequency analysis, L-moments, Algeria