Author(s)

F. Delclaux

Abstract

When uncertainty is important, the fuzzy set theory offers a framework for processing qualitative information. In such a model, variables are treated as fuzzy numbers and calculations are replaced by inference rules. Therefore, we built some tools in order to introduce qualitative knowledge in the field of hydrology. Firstly, a C library has been developed, including basic fuzzy tools. Secondly, we built a fuzzy rule model software in which several algorithms are taken into account : defuzzification, aggregation rule, logical operator definition. The case-study concerns the determination of the ten year runoff coefficient in the Sahel area for which an evaluation method is based on three variables : the area and the slope of the basin, and an infiltrability index. In the classica

Keywords