Twenthekanalen : use of GPR below water : estimating the chance of success before brining GPR into action

The Twentekanalen, situated in the east of the Netherlands near Zutphen, are going to be deepened to improve the shipping. In the past a rubble layer (consisting of slag and pitstones) has been dumped in the canal to support and protect certain parts of it. Before the dredging can take place it is important to know the amount and location of this rubble layer, to minimize the risk of unexpected costs.