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The region of Sidi Bel Abbes is periodically affected by floods and flooding. The city of Sidi Bel Abbes is exposed to very important and recurrent floods. This region is located at a lower level than the bed of Wadi Mekerra. It is equipped with three hydrometrics stations: Haçaiba Sidi Ali Benyoub and Sidi Bel Abbes. These stations have a long series: 43 years, 55 years and 64 years respectively. Statistical estimation of extreme flood has been carried out for the annual maxima. The choice the most appropriate class of law for modelling the annual maxima was made by the decision support (DSS ) of HYFRAN software system. Series of three stations belong to the class D. After classification of laws, on the basis of the posterior probability, the Bayesian information criterion ( BIC ) and the Akaike information criterion (AIC ), which take into account the statistical goodness of fit, the law gamma was selected to estimate the maximum flow frequency . [ABSTRACT FROM AUTHOR]

In Tunisia, olive tree is traditionally propagated using ovules that delays fruiting period. Using herbaceous cutting allows shortening juvenile period and enhancing productivity. The present study aims to understand the hydraulic characteristics of the conducting system of the olive-tree as related to plant material origin. Experiments were carried out within an olive grove "Chemlali", 17 years old conducted in rain-fed conditions on sandy soil in the arid region of Souassi, Gouvernorate of Mahdia (center-east Tunisia) receiving an average rainfall of 250 mm per year. Olive trees were propagated either by ovules or herbaceous cuttings and planted at 14m x 14m (51 trees/ha). Comparative study was made using parameters of water status (wood density and wood relative water contents) and anatomical observations (conducting vessels, hydraulic diameter, surface of the lumen and theoretical hydraulic conductivity). The dynamic of water use by olive shoots was also studied on both olive plant types under plastic house conditions. Results showed that conducting system characteristics of olive trees issued from herbaceous cuttings permitted a good adaptation to water stress. Those of trees issued from traditional propagating method allowed, relatively, more water loss and less water absorption. [ABSTRACT FROM AUTHOR]