scholarly journals Contemporary erosion and suspended sediment yield within river basins in the steppe of the Southeastern part of the Russian Plain: A case study of the Samara River basin

Author(s):  
A. V. Gusarov ◽  
A. G. Sharifullin

The paper presents the results of contemporary trend assessment in general erosion intensity within the southeastern steppe sector of the Russian Plain, a case study of the Samara River (the upper reaches) basin (22,800 km2, Orenburg oblast, European part of Russia), based on the long-term studying of river suspended sediment yield dynamics. The assessment is supplemented by accumulation rates field study of the soil-rill-gully erosion products in a typical small catchment (the catchment area is 1.92 km2) of the river basin using environmental radioactive caesium-137 (incl. Chernobyl-derived 137Cs) as a chronomarker. The results obtained clearly show that the Samara River’s suspended sediment yield has been reduced at least twice over the last 30 years compared with 1940–1960s. The marked decreasing trend in the erosion intensity in the Samara River basin is confirmed by a decrease (by 3.0–3.6 times as a minimum) in accumulation rates of the erosion products over the past 60 years within the dry valley bottom of the studied small catchment. The main reason for such significant erosion rates reduction was a decrease in surface snowmelt runoff within the basin area since the early 1980s, associated with a reduction in a soil freezing depth and a general increase in air temperature during spring months.

Author(s):  
Ebenezer Boakye ◽  
F. O. K. Anyemedu ◽  
Emmanuel A. Donkor ◽  
Jonathan A. Quaye-Ballard

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Albert Teixeira Cardoso ◽  
José Alexandre Pinto Coelho Filho

2019 ◽  
pp. 3-24
Author(s):  
A. V. Gusarov ◽  
L. F. Maksyutova

Suspended sediment yield is one of the objective and sufficiently accurate measures of erosion intensity in river basins. In first approximation, it can be divided into the riverbed component –r(rb), the products of vertical and horizontal riverbed deformations), and basin component – r(bas), the products of soil and gully erosion. An attempt was made to distinguish this erosion structure in the USA river basins based on the partition of suspended sediments of 224 rivers (based on the data from the US Geological Service on the average monthly water discharges and suspended sediment yields) according to the method proposed by one of the authors of the paper, as well as an assessment of its factor dependence. The average r(rb) value for the analyzed rivers of the USA is 7.9±1.1%: for lowland rivers – 10.6±1.7%, for low-mountain (including uplands) rivers – 5.7±1.5%, for mid-mountain rivers – 4.3±1.5%. The geomorphic factor, landscape and climatic conditions within the river basins have a major impact on the suspended sediments flux ratio r(rb)/r(bas). Thus, in the USA plains, the largest average r(rb) portion is in the forest landscapes (taiga, mixed and broadleaf forests of the temperate zone, subtropical forests) – 10–15%. On the contrary, in the arid landscapes (semi-deserts) this value does not exceed 1%. Within these general trends, there are quite strong variations in the r(rb)/r(bas) ratios due to the changes in high river basin areas, agricultural activities and lithologic composition of the riverbed and floodplain sediments. There is an inverse hyperbolic relationship between the actual suspended sediment yield of rivers and the riverbed sediment portion (r(rb)), which is most manifested in the plains and low-mountains of the USA. It is also shown that a composition of the river basin parent (surficial) rocks does not play a significant role in the variability of the r(rb)/r(bas) at this scale of the study. A comparison of the r(rb)/r(bas)-estimates and their factor dependence on the US rivers with the rivers of Northern Eurasia (the territory of the former Soviet Union) makes it possible to reveal good convergence of the results obtained in these parts of the Earth, and to suggest the universal nature of the revealed regularities (in total for 684 river basins) for the whole temperate (partly for subtropical and tropical) zone of the Northern hemisphere of our planet.


Water ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 966 ◽  
Author(s):  
Yuyan Zhou ◽  
Y. Xu ◽  
Weihua Xiao ◽  
Jianhua Wang ◽  
Ya Huang ◽  
...  

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