Corresponding author: Dmitry E. Klimenko (listopad19531@mail.ru)
Keywords: forest hydrology; mapping, GIS-technologies; forest science, rainfall floods, modeling, canopy rainfall interception
Abstract. Metering of actual volume of rainfall flowing under the canopy of the taiga zone trees is a crucial factor of correct calculation of the maximum water flow in small rivers. This is because only part of the rainfall that has fallen through the forest canopy and reached the soil joins the river runoff. The article presents the results of physical simulation of maximum rainfall retention on the crowns of taiga stands of the Middle Urals () as well as the results of mapping the values of interception and its determinants for the model watershed. The findings of this study help to understand how the maximum flood runoff is formed, and this knowledge is essential today as various hydrological models are being developed. The authors have mapped the species composition, height, and density of forest crowns based on satellite imagery, air photographic mosaics, and field research findings. The technique of mapping rainfall losses on vegetation has been developed, which could be of great interest for improving the quality of hydrological models used in global practice.
Rainwater is retained on the crowns in drip form (drop size ranges from 10.6 to 18.6 mg). Specific water retention (mass per unit of the leaf surface area) depends on the roughness of laminae (or needles). Absolute retention of drops on the crowns depends on the leaf surface area and rainfall intensity. The maximum mass of water retention on the crowns of detached deciduous trees is up to (3.0- per projection area of the crown), whereas that of coniferous trees ranges from 24.8 to (1.9 to ).
Based on the developed map model of rainfall interception, genetic methods were used to calculate the hydrograph of a single rain flood for the model watershed of the Reshetka river. Taking into account the rainfall loss through crown retention, it is possible to reduce calculation errors of maximum flood water flow from 126 to 25%.