Anthropogenic transformation of river network in the Otava river basin

Abstract

The article is focused on the analysis of effect of the anthropogenic transformation of the river network on the course and consequences of floods. The process is analysed on the example of Otava river basin which is located at the core zone of the extreme floods iii August 2002 in Central Europe. The assessment stems from large-scale field mapping of current intensity of transformation of the riverbed, river longitudinal profile, floodplain and the river course. More than 600 km of streams representing the backbone of Otava river basin was mapped using a newly developed mapping methodology allowing integration of the results in (HS and their consequent geostatistical treatment. The results prove the high intensity of riverbed and floodplain modifications mainly in the agricultural landscape as well as the intensive transformation of longitudinal profile of the rivers. The anthropogenic changes of streams importantly affect the hood course and hood consequences and the experience from 2002 flood in the Otava river basin proves this relation. The mapping methodology presented in the article thus can be used as efficient tool to identify the critical segments of the river network with regard to the flood risk and to improve the hood protection planning process