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Reconstructing the development of a gully in the Upper Kalaus basin, Stavropol region (southern Russia)
Author(s) -
Belyaev V.R.,
Wallbrink P.J.,
Golosov V.N.,
Murray A.S.,
Sidorchuk A.Yu.
Publication year - 2004
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.1025
Subject(s) - geology , hydrology (agriculture) , surface runoff , drainage basin , sediment , period (music) , structural basin , gully erosion , erosion , flood myth , geomorphology , geography , archaeology , ecology , physics , geotechnical engineering , cartography , acoustics , biology
The Stavropol region of southern Russia is severely affected by human‐induced gully erosion. A lack of detailed information on the different stages of gully formation resulting from major agricultural expansion c . 100 years ago, is an obstacle for management and containment of these systems. In this study we combine measurements of particle‐bound radionuclides ( 137 Cs, 210 Pb ex , 226 Ra, 232 Th and 40 K) and classical geomorphology to investigate and reconstruct the different phases of development of a gully during the last c . 100 years. We believe the rst phase (1) involved an initial incision into the bottom of a small valley (catchment area c . 1 km 2 ) about 100 years ago. A short period of rapid growth was followed by a longer stage of gully stabilization. Subsequent phases were: (2) the period 1954–1960 – re‐incision in the lower gully reach was initiated by a high‐magnitude rainfall event, and a substantial amount of sediment was delivered to the gully fan; (3) c . 1960–1986 – the knickpoint retreated slowly, sediment was redeposited nearby, and the fan surface became stable; (4) 1986–1987 – a dam was built in the gully mouth and breached shortly after construction following 2 days of high rainfall, and substantial sediment accumulated in the gully above the dam and below the spillway channel on the fan surface; (5) 1987–1993 – the knickpoint retreat continued and the lower fan surface was stable until 1993 when the last signicant runoff event overlayed it with c . 10 cm of fresh sediment. These detailed reconstructions of gully development stages allow the contribution of high‐magnitude events to gully growth and regional sediment delivery to be assessed. They further guide management actions to prevent such dam failures in the future. Copyright © 2004 John Wiley & Sons, Ltd.