ABSTRACT
Although the impact of colmation and clogging processes on interstitial habitats of gravel bed rivers is well known no standard method is available to quantitatively assess colmation. This is due to the complexity of involved physical, chemical and biological processes but also due to overlaying scales. In this paper, results of different projects are presented facing the challenge to measure clogging processes. The presented methods consist of mapping, a novel multi-parameter approach and laboratory experiments. While mapping allows only for qualitative assessments, the multi-parameter approach aims at the quantification of involved parameters such as particle sizes, porosity, dissolved oxygen and hydraulic conductivity. The laboratory experiments help to unravel the influence of distinct processes during clogging but due to the required simplifications the laboratory results might not directly be representative for natural conditions. Therefore, a combination of different methods is recommended to increase the knowledge about the phenomenon colmation.
