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A.Racinskas
Abstract
The present article represents an analysis of some regularities of wind erosion in
Lithuania. It is based on the investigation data collected in 1988-1991 by researchers
from the Institute of Geography (Morkunaitė, Paskauskas, Minkevicius) headed by the
author. The field investigations were combined with the laboratory experiments in a wind
tunnel. From the data of laboratory experiments, a mathematical model of wind erosion
dependence on a number of factors was created:
D = -1789 ± 450v - 357g - 105h - 45m
where D = the volume of blown out soil, t/ha/h; v = wind speed m/s; g = diameter of
equivalent soil aggregates, mm; h = humus, %; m = content of physical clay, %.
Following this model the Lithuanian territory was estimated from the point of view of
susceptibility to wind erosion (scale numbers). The lowest category of susceptibility to
wind erosion (<0.5...3.0 scale numbers) includes the loam and clay soils of rather good
structure of Middle and North Lithuanian plains (Kedainiai, Marijampole, Pasvalys, etc.
districts).
A comparatively low susceptibility to wind erosion (0.5...3.0, in rarer cases
3.0...6.0) is characteristic of Lithuanian uplands where morainic sandy loams and loams
prevail (Telšiai, Molėtai, Trakai, etc. districts).
A comparatively low susceptibility to wind erosion of Southeast Lithuanian
fluvioglacial sandy plains (0.5...3.0, 3.0...6.0, in rare cases >6.0) is conditioned by
the lowest in Lithuania probability of stronger winds.
The highest susceptibility to wind erosion (10...20, in separate cases till 40-60) is
characteristic of the Lithuanian Coastal Plain (particularly the Silute district). This is
conditioned by a wide distribution of fine-grained alluvial sands and 2-3 times higher
probability of recurrence of strong winds. |
