标题：Response of lateral channel dynamics of a lowland meandering river to engineering-derived adjustments - an example of the Morava River (Czech Republic)
摘要：Abstract
Freely meandering (quasi)natural reaches of
lowland rivers represent a rare phenomenon in Central Europe.
Increasing attention is currently being paid to the
dynamics of quasi-natural (artificially influenced) meandering
rivers as this attention represents the basic prerequisite
for the development of appropriate restoration
strategies on regulated rivers. This study focused on a 5.5
km long reach of the Morava River in the Strážnické Pomoraví
region, Czech Republic that is characterised by
quasi-natural evolution after substantial engineering adjustments
were made in the first decades of the twentieth
century. Based on Geographic Information Systems (GIS)
analysis of aerial photographs, the spatio-temporal dynamics
of bank erosion and accretion rates were quantitatively
described and variables that control channel migration
rates were identified. High rates of lateral shifts were
localised in high sinuosity segments (sinuosity 1.17-2.37),
whereas segments with very low rates were straight or
formed into slightly curved bends (sinuosity 1.05-1.18). As
a key factor, engineering works that influenced local river
bed slope and induced a dramatic increase in bank erosion
rates were identified. River engineering works induced a
dramatic increase in bank erosion rate (2.19 m/year for
1938-53 and 1.47 m/year for 1953-63). An interval of approximately
25 years was needed before the erosion rates
dropped back to values documented before river regulation
(0.35-1.09 m/year for 1841-1938). Other important controlling
variables included radius of curvature, frequency
and magnitude of floods and, locally, river bank material
properties and floodplain land cover.
关键词：Keywordsmeandering rivers channel planform changes
river regulation GIS Morava River
