Macrophytes have an important influence on water flow, sedimentation processes and nutrient dynamics in lowland rivers. Besides a temporal variation in vegetation throuhout the year a strong spatial heterogeneity occurs. To study the cascade- and feedbackeffects in the riverecosystem there is a need for integrated modelling in which the different processinteractions are incorporated. The aim of the PhD research is to develop a 2D hydraulic module en vegationmodule within the modelpackage STRIVE. The 2D modules will be validated with already available data and new (field) experiments.