Tuesday, 11 July 2017

Two-hundred years long history of direct human impact on Beskydian headwater channels

Two new scientific publications were released from the area of the Moravskoslezsk√© Beskydy Mts, which deal with direct and indirect human impact on local steep channels. Our recent article in Catena describes the geomorphic impact of stream crossings on adjacent channel reaches. Under co-operation with dedrologeomorphologists from Dendroman group, we reconstructed the history of channel incision downstream culverts. We also documented notable changes in channel geometry upstream and downstream these constructions together with the size of bed sediments, which could have a negative effect on local biota. 

The scheme of observed geomorphic effects of culverts. 

The history of direct (torrential works, timber floating, instream wood removal) and indirect (land use changes related to sediment supply) impact on Beskydian streams is now comprehensively presented in the article published in Geografie (in Czech, but with English summary). We documented that although the Moravskoslezsk√© Beskydy Mts were for a quite long period without settlements or extensive medieval mining activity, the indirect impact began at the turn of 15th and 16th in relation to Vallachian and Pastoral colonization. Later in 19th century, many streams were used as transport routes for timber, which is still reflected in their recent cross-sectional geometry. Since 1906, torrential works have been applied and recently, up to 150 km of stream courses is managed by artificial bank stabilization and grade-control structures (check-dams, block ramps).       

Check-dam built in 1920s in the Mor√°vka Basin.