Design of a watercourse and riparian strip monitoring system for environmental management.

Watercourses are complex ecosystems where numerous economic, ecological and heritage issues converge. To ensure their efficient management it is essential to have a full description of these multifunctional ecosystems and to know their evolution over time. This paper describes a method for monitoring watercourses and their riparian strips developed in Wallonia (southern Belgium). It is based on an inventory constructed by stratified random sampling comprising 1,071 sampling plots distributed over a total length of 24,600 km of watercourses covered from their source. Each sampling plot is surveyed and measurements and fine observations are made on watercourse segments 50 m long. The method developed, which was applied on a regional scale, could easily be transposed to other entities, from large river basins, to an entire country. Examples of results obtained from a first inventory phase demonstrate the utility of this tool designed to supply qualitative and quantitative information to assist watercourse management.