The research of deformation processes in regulated streams

Abstract

Different kinds of defornnation occur in the most regulated rivers and stream channels. That courses the changes of stream channels in cross-sectional and longitudinal profiles. Regulated streams banks overgrovv with dense grass and woody vegetation. That creates favorable conditions for the accumulation of sediments, what rises channel silting and channel's slopes reduction. In that cases naturalization processes evidence in the regulated stream channels. The objective of research is to estimate the self-naturalization of regulated streams. The main tasks to achieve the objective of the study are to evaluate the deformations occurring in regulated stream channels of the Jiesia catchment and to determine the reasons of their occurrence. The technical statė of regulated streams in randomly selected 58 places was analyzed. Sections of regulated streams of the Jiesia catchment vvere selected for the studies in respect of their designed bed slope and type of soil prevailing. Having summarized the study results it was determined that the deformations of slopes and channel bed are the most frequent deformations occurring in regulated streams. The most significant deformations occur in the zone of channel flow. In 63.4% of all studied cases large amounts of sediment and soil particles accumulate here forming a 0.2-0.40 m thick layer. Also during the formation of deformations on channel slopes, meandering of channel bed was occurred in 67% of all the studied cases. Changes in the profile of regulated streams and non-maintenance of the streams induce the development of naturalization processes in regulated streams.