History and expectation of investigations on sediment yield with the Upa River basin

The Upa River basin is located in the Northern part of the Central Russian Upland. This is the area with a high proportion of cultivated lands and at the same time, the part of the basin was affected by serious radioactive contamination after the Chernobyl accident in 1986. Chernobyl-derived ¹³⁷Cs turned to be a very suitable tool for assessing mean rates of erosion and accumulation during the post-Chernobyl period. A high concentration of radionuclides in soils and accumulated sediments results in a rapid examination of a large number of gamma-radiation measurements, including in situ measurements, and obtaining a large amount of data, which were published in international and national scientific journals during last years.

Using radiocesium techniques the series of small key catchments, floodplain sites, and artificial reservoirs were explored. The evaluation of sediment budget and resulting sediment yield required adequate extrapolation of achieved results over the territory of the Upa River basin for the desired period. Presented work is argued to generalize results obtained in different locations of the Upa River basin during the last 26 years (from 1995 to 2021). Sediment yield for the two big parts of the basin was assessed: the Plava River basin and the basin of the Sheckino reservoir, located in the Upper Upa basin.

Taking in mind observed experience and resulting estimations, the expectation of the following studies are discussed. Future studies may be split into three directions. The first is linked to the inclusion of new techniques and a combination of new techniques during field studies and lab processing. The second direction of investigation is related to the creation of monitoring systems within basins of typical small rivers. The third is one is an exploration of environmental archives like bottom and floodplain sediments, which may record trends in formation sediment yield for the territories not covered with hydrologic and sedimentary observations for the last decades. 

The work was conducted under financial support of the Russian Scientific Fund, project 21-55-00050