SPATIAL-TEMPORAL ASPECTS OF THE HYDROLOGICAL REGIME IN CATCHMENTS AFTER CLEARCUTTING

Abstract

This article discusses the spatial and temporal aspects of hydrological processes in catchments after logging for different landscape conditions of Central Siberia. For this discussion, the results of our own research in the Sayan Mountains, the Yenisei Ridge, the Angara River basin, the Khamar-Daban ridge and literature data were involved. It analyzed the impact of felling area to change the river flow and development of the erosion at the catchment area. The annual runoff, its seasonal structure and sediment discharge change significantly in dependence on as area of clearcutting so area of river basin. The authors analyzed the results of observations of the restoration of the water balance in the experimental logging sites of small catchments and the dynamics of runoff in large rivers. Research has shown the vegetation cover structure changes continuously on logged sites during post-logging forest regeneration and future post-cutting hydrologic regime scenarios are determined both by further climatic changes and by vegetation succession trajectories. The role of the time as a factor to decrease erosion at watershed after logging depends of many regional and local features of landscapes and of initial soil mineralized by logging. For the forests of Khamar-Daban mountainous in Baikal basin the model of soil erosion at watersheds after logging was developed.