Channel sinuosity of the Körös River system, Hungary/Romania, as possible indicator of the neotectonic activity

The Körös River Drainage Basin is located in the eastern part of the Great Hungarian Plain, west of the Apuşeni Mts., in the middle of the Pannonian Basin. The channels of the river and its tributaries are mostly meandering, characterized by large loops and multiple bends in their pre-regulation form. The channel sinuosity of this river system is analyzed in order to draw conclusions on the neotectonic activity of the eastern region of the Great Hungarian Plain. The original, pre-regulation status of the river thalwegs was digitized from rectified historical maps. Sinuosities at different sample section lengths were computed in a GIS software environment, providing so-called ‘sinuosity spectra’ for each point of the analyzed channels. High sinuosity sections were correlated to linear features identified in seismic survey sections, indicating their neotectonic activity. Some low sinuosity sections, former marshlands and a special river section having anastomosed planform suggest zones of rapid subsidence. All of the above features cannot be verified by the topography as the relief in this area is below 10 m.