  Water resource management is of crucial societal and economic importance,
requiring a strong capacity for anticipating environmental change. Progress in
physical process knowledge, numerical methods and computational power, allows
us to address hydro-environmental problems of growing complexity. Modeling of
river and marine flows is no exception. With the increase in IT resources,
environmental modeling is evolving to meet the challenges of complex real-world
problems. This paper presents a new distributed Application Programming
Interface (API) of the open source TELEMAC-MASCARET system to run
hydro-environmental simulations with the help of the interoperability concept.
Use of the API encourages and facilitates the combination of worldwide
reference environmental libraries with the TELEMAC-MASCARET system.
Consequently, the objective of the paper is to promote the TELEMAC-MASCARET
system for studies dealing with such issues as uncertainty propagation, global
sensitivity analysis, optimization, multi-physics or multi-dimensional
coupling. To illustrate the capability of the API, an operational problem for
improving the navigation capacity of the Gironde Estuary is presented. The API
potential is demonstrated in a re-calibration context. The API is used for a
multivariate sensitivity analysis to quickly reveal the most influential
parameters which can then be optimally calibrated with the help of a data
assimilation technique.
