Modélisation non paramétrique de la relation entre les caractéristiques du vent et la différence de niveaux sur un grand réservoir

Abstract

The natural inflow at a site is a key variable for optimal management of water resources, particularly for hydroelectric production. For sites with dams and hydroelectric powerplants, this variable cannot be measured directly, and the water balance equation is used to determine the quantity of water a site receives on its surface during a certain period of time. However, several errors affect the natural inflows computed this way. One of the principal sources of uncertainty for large reservoirs is the nonrepresentativeness of water level because of the wind effect. To quantify the effect of wind on the reservoir surface, a nonparametric regression model was used to relate the water level differences between several stations located on the same reservoir and the characteristics of the wind (direction and intensity). The study showed that the nonparametric regression model substantially improves the knowledge of the water level differences between several stations when there is presence of wind. With this model, it is possible to characterize the types of wind affecting the reservoir and to establish validation strategies for the data. The studied reservoirs are Outardes-4 and Gouin, two large reservoirs located in the north of the province of Québec, Canada.Key words: wind, reservoir, water level, nonparametric regression, natural inflow, performance criteria.