Processes of runoff formation at the Putorana Plateau (Central Siberia, Russia)

Abstract

<p>The Putorana Plateau is located in the North-West of the Central Siberian Plateau in the Krasnoyarsk Territory in permafrost zone. Some mountain peaks reach a height of 1400 - 1700 m. The plateau is composed of stepped canyons formed by the outpouring of a huge mass of red-hot basalts. The Putorana Plateau is the territory that is still unexplored in hydrological terms. Climate change contributes to an increase in the thickness of seasonal thawing, therefore, the conditions of runoff formation change.</p><p>The purpose of the work is to study the factors of runoff formation, including the research of geocryological conditions based on short-term expedition data of the State Hydrological Institute (St. Petersburg, Russia) collected in small catchments in 1988-1990.</p><p>The object of study is the catchment of the stream Dupkun (an area of 2.75 sq. km), which is located in the basin of the Kureyka river basin, the right tributary of Yenisei River in the southwestern part of the Putorana Plateau. The maximum height of the catchment is 1228 m, and the hydrological gauge is located at an altitude of 923 m. The average slope of the catchment area is 12°. The landscape is a moss-grass mountain tundra, and perennial snowfields are also formed.</p><p>The expedition studies in the period from July 19 to September 4, 1990 included the collection of hydrometeorological information, the determination of soil characteristics (moisture content, temperature, structure at different depths and landscapes), and the study of snow cover. The route studies were conducted to determine the characteristics of landscapes, vegetation and soils in the basins of the rivers Kureyka and Khantayka.</p><p>The data of the expedition studies were processed, digitized and systematized.  Based on the collected material, the water balance of the stream Dupkun was calculated. The presence of perennial snowfields has a significant impact on the formation of runoff. At the beginning of observations, the area of snowfields was 15 %, the average snow height was 2.6 m, and the average density was 0.7 g / cm<sup>3</sup>. At the end of observations, snowfields occupied 8% of the catchment area. For 20 days, the snowmelt depth was 38 mm, the precipitation reached 140 mm, and the runoff was 167 mm. The runoff coefficient is 0.89. During the entire observation period, the runoff reached 355 mm.</p><p>These observations are considerable value due to the lack of knowledge of the geocryological, landscape and hydrological conditions of the Putorana Plateau. Since there are practically no hydrological stations in this region that study the processes of flow formation, the collected data become even more unique. Extremely scarce data allowed to conduct the assessment and verification of the parameters of the hydrological model "Hydrograph". The developed set of the model parameters was used to simulate the river flow of tundra landscapes of the Putorana Plateau and assess its contribution to the formation of the water balance of the territory in the current climate.</p><p>The study was supported by the RFBR (project No. 19-55-80028).</p>