VALIDATION OF HYDROMETRIC DATA USING UNIV ARIATE FILTERING TECHNIQUES

This study aims at validating the historical hydrological data. For th e purpose of clarity, the paper has been divided into two parts. The f irst part, a theoretical one, presents a very broad range of filtering techniques that goes from the simple filter, using the median or the moving average, to the Fraser smoother coupled with the Kalman one. A chronological series simulated and then artificially affected by noise effects, simultaneously with white noise and a certain number of high -amplitude perturbations, was conceived. Its use should allow to reach conclusions regarding the validity and performance of the different f ilters. The second part, a practical one, uses several actual historic al series relative to measures of the water level in a reservoir, the natural inflow, and inlet and outlet flows. Its essential objective is to validate the natural inflow data (calculated by hydric balance). A general chart of the procedure employed to carry out this validation is thus presented. The results obtained are then compared. All the tec hniques are used so as to make the validation automatic. This resulted in creating a very general application software called Valideb. It al lows the user to analyze and judge the results of a filtering method a nd its effect on each component of the hydric balance.