Assessment of modern shoreline transformation rates on the banks of one
of the largest reservoirs in the world (Kuibyshev reservoir, Russia)
using instrumental methods
Abstract
The study object is the Kuibyshev reservoir. The objective is to
quantitatively assess reservoir bank landslides and shoreline abrasion
in active zones based on the integrated use of modern instrumental
methods. Different approaches are used to assess the intensity of
landslide and abrasion processes: the specific volume and material loss
index, the planar displacement of the bank scarp, and the
planar-altitude analysis displacements of soil masses based on the
analysis of slope profiles. Shoreline position for the past periods
(1958, 1985, and 1987) was obtained from archival aerial photography
data; data for 1975, 1993, 2010, 2011, and 2012 were obtained from
high-resolution satellite image interpretation. Field surveys of these
geomorphic processes at the study areas in 2002, 2003, 2005, 2006, 2014
were carried out using total stations; in 2012-2014 using terrestrial
laser scanning and a UAV survey in 2019. The monitoring of landslide
processes showed that the rate of volumetric changes at Site 1 remained
rather stable during the measurement period with net material losses of
0.03-0.04 m3/m2/year. The most significant contribution to the average
annual value of material loss was by snowmelt runoff. The landslide
scarp retreat rate at Site 2 showed a steady decreasing trend, due to
partial overgrowth of the landslide accumulation zone resulting in its
relative stabilization. The average long-term landslide scarp retreat
rate is 2.3 m/year. In recent years, landslide control measures realized
at this site have reduced the landsliding intensity by more than 2.5
times to 0.84 m/year