The head of the project: Valentin N. Golosov
The title of the project: Quantitative assessment of the slope sediment flux and its changes in theHolocene for the Caucasus mountain rivers
Key words: sediment yield, catchment erosion, denudation, river basin, sedimentation, sediment dating, floodplain, lakes, Holocene, trends, climate changes, anthropogenic changes, sediment sources
Summary
Mountains occupy a significant part of the territory of Russia. The Caucasus Mountains are not only the most densely populated region, but also a territory important for the development of medical and health resorts, agriculture, hydropower generation, and industrial production, as well as mining, and transport infrastructure. In natural perspective, the mountains of the Caucasus are also of great importance. Present here is the full range of altitudinal zonation except for the tropics. It ranges from the humid subtropics of the Black Sea coast to the glaciers of the Greater Caucasus Mountains. The intensity of the processes of erosion and accumulation in various altitudinal zones of the Caucasus and their changes over time can be viewed as a reflection of the fluctuations of climate and of the anthropogenic impact, that has intensified during recent decades. The increasing recurrence of events associated with the formation of extreme floods, the passage of powerful destructive mudflows, requires producing detailed quantitative assessments of the characteristics of the formation of solid run-off in the watersheds at various altitudinal belts. This is necessitated by the fact that the material entering permanent watercourses due to the manifestation of various denudation processes is prepared within the limits of the slopes. However, there are currently no quantitative estimates of the intensity of denudation processes and of the sediment delivery rates from slopes to the permanent watercourses for various altitudinal belts. Some other data is lacking as well that is required for producing the engineering calculations and the development of measures to prevent the negative effects of extreme floods. There also have been no studies addressing the changes in denudation rates of watersheds at various altitudinal belts of the Caucasus Mountains, occurring against the background of climatic fluctuations and increased anthropogenic impact during the Holocene. The key issues are the assessment of the rates of various denudation processes, their relative input into the formation of the riverine runoff, the relevant impact of climate change, and the anthropogenic impact on the rate of denudation at different altitudinal belts. Here we consider both the impact the present climate changes and the impact of changes observed during the Holocene. The above points form the essence of the relevance of this project.
Within the framework of the project, the following interrelated tasks will be solved for the objects selected for detailed research within the different altitudinal belts of mountains (i.e. for the watersheds of 3-4 mountain lakes and 3 minor rivers):
a) quantitative assessment of the rates of the current exogenous processes
b) mapping of the material transport routes from the slopes to the permanent watercourses and the assessment of sediment delivery rates entering from the slopes into the permanent watercourses and/or water reservoirs
c) assessment of the contribution of various sources into the formation of the riverine sediment flow
d) dynamics of changes of the denudation rates for different time intervals within the Holocene and the influence of climate change and anthropogenic activity on them
e) forecast of probable changes in the basin component of the sediment discharge of the rivers of the Caucasus depending on various scenarios of climate change and possible changes in anthropogenic burden
Over the past decades, a large set of methods has been developed and widely tested, namely field, analytical and remote sensing methods for the quantitative assessment of various exogenous processes, redistribution of sediments on the slopes of the catchments, and dating of the sediments in the zones of accumulation. The combined application of the traditional, improved and newest methods will allow to quantitatively characterize the features of the formation of the basin component of the sediment flow and its changes over time for the selected objects (i.e. the catchment areas of three mountain lakes and three small rivers). This implies employing the following:
-a set of field methods for quantifying the rates of various exogenous processes (including laser scanning from the unmanned aerial vehicles (UAVs), the trap method, the hairpin method, etc.), as well as the collection of the bottom sediments
-methods for estimating redistribution sediments along the pathway of their transport from the slopes to the permanent watercourses and reservoirs (method of the large-scale geomorphological mapping in combination with the use of the graph theory)
-methods of identifying the relative contributions from various sources of sediments using a set of tracers (fingerprinting technique);
-remote sensing methods (including the decoding of high-resolution aerial and satellite images, the method of stable reflectors, etc.);
-analytical methods for studying bottom and floodplain sediments and the sediments re-deposited on the slopes along the pathway of their transportation to the permanent watercourses (radiocarbon dating, radioisotope dating, AMS, etc.)
The comprehensive coverage of the currently unsolved problems associated with the formation of the basin component of the river runoff of the various altitudinal belts of the Caucasus mountains and its changes over the Holocene period combined with employing a set of traditional and latest research methods form the novelty of this project.
The expected results
As a result of the project we will perform the quantitative assessment of the modern rates of the main earth surface processes at various altitudinal belts of the Caucasus Mountains, determine the coefficients of the sediment transport from the slopes to the river valleys, estimate the contribution of various sources of sedimentation of the basin provenance in the river sediment flux, reconstruct the dynamics of the variations of the rates of denudation on the slopes of the catchment area during the Holocene for the middle- and high-altitude belts and define the factors responsible for these changes. Basing on the results and with the use the of existing predictive climate models we will provide a forecast of the variations of the slope sediment flux for the Caucasus rivers draining various altitudinal belts. The revealed regularities and relations of the formation of the sediment flux of in the catchment areas of the Caucasus rivers during the Holocene allow to assess the dynamics of transformation of the relief as a basis of the landscape and define the changes in the frequency of the extreme erosion events during the Holocene depending on climate, tectonics and human impact. The level of research planned within the project complies with the international standards both in terms of the applied research methods and in further understanding and revealing the connections in the mechanisms and rates of formation of friable and clastic material and its further redistribution following the transport from the slopes to the river valleys and reservoirs. In terms of complexity of the planned research the project is unique.
The results of the project can be used for: a) development of anti-mudflow and flood control measures in the basins of the mountain rivers; b) construction of transport systems, water-storage basins, infrastructure objects; с) optimized allocation of tourist and recreational objects within river basins at various altitudinal belts of the Caucasus; d) creation and use of irrigation systems in the mountains and foothills; e) agricultural use of mountain slopes (optimized load on pastures, slope terracing, etc.)
Among the primary implementations of the results of the project in social sphere is in education, essentially that means formation of modern Russia’s scientific and scientific-educational stuff in the area of Earth sciences, since the majority of the participants of the project is comprised of the young scientist category. We plan to include the results of the project into the existing bachelor and master courses of the MSU Geographical faculty, as well as to develop a number of specialized courses for bachelors and masters within the concepts “Geography”, “Cartography and GIS” and “Ecology and nature management”. Two PhD theses are planned to be prepared basing on the results of the project.
As a result of the project we will perform the quantitative assessment of the modern rates of the main earth surface processes at various altitudinal belts of the Caucasus Mountains, determine the coefficients of the sediment transport from the slopes to the river valleys, estimate the contribution of various sources of sedimentation of the basin provenance in the river sediment flux, reconstruct the dynamics of the variations of the rates of denudation on the slopes of the catchment area during the Holocene for the middle- and high-altitude belts and define the factors responsible for these changes. Basing on the results and with the use the of existing predictive climate models we will provide a forecast of the variations of the slope sediment flux for the Caucasus rivers draining various altitudinal belts. The revealed regularities and relations of the formation of the sediment flux of in the catchment areas of the Caucasus rivers during the Holocene allow to assess the dynamics of transformation of the relief as a basis of the landscape and define the changes in the frequency of the extreme erosion events during the Holocene depending on climate, tectonics and human impact. The level of research planned within the project complies with the international standards both in terms of the applied research methods and in further understanding and revealing the connections in the mechanisms and rates of formation of friable and clastic material and its further redistribution following the transport from the slopes to the river valleys and reservoirs. In terms of complexity of the planned research the project is unique.
The results of the project can be used for: a) development of anti-mudflow and flood control measures in the basins of the mountain rivers; b) construction of transport systems, water-storage basins, infrastructure objects; с) optimized allocation of tourist and recreational objects within river basins at various altitudinal belts of the Caucasus; d) creation and use of irrigation systems in the mountains and foothills; e) agricultural use of mountain slopes (optimized load on pastures, slope terracing, etc.)
Among the primary implementations of the results of the project in social sphere is in education, essentially that means formation of modern Russia’s scientific and scientific-educational stuff in the area of Earth sciences, since the majority of the participants of the project is comprised of the young scientist category. We plan to include the results of the project into the existing bachelor and master courses of the MSU Geographical faculty, as well as to develop a number of specialized courses for bachelors and masters within the concepts “Geography”, “Cartography and GIS” and “Ecology and nature management”. Two PhD theses are planned to be prepared using the results of the project.
