CHARACTERISTICS OF HEAVY RAINFALL
PARAMETERS
IN THE NORTH-WESTERN ROMANIA
T. TUDOSE , F. MOLDOVAN
ABSTRACT. - Characteristics of heavy rainfall parameters in
the north-western Romania. The paper analyzes the frequency, duration, intensity
and quantity of heavy rains in north-western Romania, based on data from 14
meteorological stations in that area, located in different terrain conditions,
using 1975-2009 period. Identification of the torrential rains was made on
Hellmann’s criteria. In the review period were identified 271 torrential
rainfall events, representing only 0.89% of all precipitation cases with
significant intensity in generating liquid surface flow. During the year, the
highest frequency of occurrence is from June to August (between 61.5 and 90% of
cases), with a slight predominance of June. In terms of duration, the highest
shares of torrential rains have 3-6 hours (37.3%), followed by those of 1 to 2
hours (25.1%), this structure revealing different genetic conditions. Diurnal
variation shows maximum occurrence of heavy rains in the afternoon and evening
(between 13 and 20 Romanian Summer Time - RST), the phenomena starting earlier
in mountainous areas (11-12 RST) and later in the lowlands (16-17 RST). Water
amounts varies quite large, with values ranging between 1.2 and 82.7 mm, and
their average intensity is between 0.12 and 1.80 mm/min, being noticed a strong
correlation between average duration and intensity of rainfall, it ultimately
reducing the growing period.
Keywords: heavy rain, diurnal variation, intensity, Northwestern Romania