Data Assimilation in Hydrology: Variational Approach

Abstract

Predicting the evolution of the components of the water cycle is animportant issue both from the scientific and social points of view. The basic prob-lem is to gather all the available information in order to be able to retrieve at bestthe state of the water cycle. Among some others methods variational methods haveastrongpotentialtoachievethisgoal.Inthispaperwewillpresentapplicationsofvariational methods to basic problems in hydrology: retrieving the hydrologic stateof at a location optimizing the parametrization of hydrologic models and doing sen-sitivity analysis. The examples will come from surface water as well as undergroundwater. Perspectives of the application of variational methods are discussed.