THE DYNAMICS OF CONTEMPORARY GULLY EROSION ON ARABLE LAND IN THE WESTERN PRE-KAMA REGION OF THE REPUBLIC OF TATARSTAN (RUSSIA)
A.G. SHARIFULLIN1, A.M. GAFUROV1, V.N. GOLOSOV2,3, A.P. DVINSKIH1, R.A. MEDVEDEVA1
1Kazan (Volga Region) Federal University, 420008, Kazan, ul. Kremlevskaya, 18, Russia
luleo123@mail.ru
2Lomonosov Moscow State University, 119991, Moscow, Leninskie gory, 1, Russia
gollossov@gmail.com
3Institute of Geography, Russian Academy of Sciences, 19017, Moscow, Staromonetnyi per., 29, str. 4, Russia
Keywords: линейный и площадной прирост, талый сток, малый водосбор, изменение климата, дешифри рование спутниковых снимков, балка "Темева речка", gully erosion, linear and areal retreat rates of gullies, snowmelt runoff, catchment, climate change, interpretation of satellite imagery, Temeva Rechka dry valley
Abstract
The article presents the results of linear and areal retreat rates of gullies in the territory of the Western Pre-Kama region of the Republic of Tatarstan as obtained on the basis of the stationary observations and interpretation of high-resolution satellite images for the periods 1983-1994, 2000-2014 and 2015-2018. The results from monitoring the gullies and interpretation of satellite images indicate comparable rates of linear headcut retreat rates. Analysis of observational data shows an uneven character of the gully headcut retreat as well as indicating a reduction in the rate of development of gully erosion in the current decade compared with the period of 1983-1994 about twice in the Western Pre-Kama region and by a factor of 7 within a small catchment. It was established that, in spite of cessation of the linear growth, about 66 % of all the gullies under investigation continue their development by increasing the width, or areal retreat. The average area growth of gullies for the entire territory of the Western Kama region is 22 m 2 per year, and for a separate catchment it is 1.5 m 2 per year. It is shown that the chief reasons behind the decrease in the growth of gully headcut is climate change, which manifests itself in a rise of winter-spring air temperatures, a reduction of the duration of the cold period, an increase in the occurrence frequency of thaws and decreases in the depth of soil freezing as well as anti-erosion measures (construction of hydraulic structures and protective afforestation) which were actively introduced in the 1990s throughout the territory of the Republic of Tatarstan. The influence of land use has most likely played a secondary role.
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