Digital modeling of lateral water fl ows and caesium-137 at the microlandscape level in semi-hydromorphic soils of the Bryansk region

Abstract

A significant role in the movement of water in the soil profile belongs to the preferential vertical water flows, while less attention is paid to the study of lateral flows. We propose a method for studying lateral moisture flows at the microlandscape level using 137Cs of “Chernobyl” origin. For GIS modeling of lateral transport, the hydrological attributes of the microrelief were used, based on a digital relief model (DEM) at a scale of 1:200 with a horizontal section of 20 cm. The Catchment Areas, the Overland Flow Distance, the ephemeral Tricle Network (Strahler Order),
as well as the topographic humidity index (TWI) qualitatively characterize the intensity of soil moisture, as well as lateral flows at the microlandscape level. Th e idea of “preferential lateral flows” introduced by analogy with vertical “preferential moisture flows”. Due to the spatial features of the structure of the nano- and microrelief, lateral transfer forms ephemeral patterns with different humidification modes: “finger-like”, filamentous, and others. A weak level of lateral migration of 137Cs was revealed depending on DEM derivatives.