Hydrological Risk Phenomena Caused By Rainfalls In The North-western Part Of Romania

Abstract

The surveyed territory occupies partially the mountainous region of the Carpathian Mountains, the range of sub-mountainous depressions, the hills from the Somes Plateau and the northern part of the Transylvania Plain. Most of its territory is drained by the Somes river. Among the extreme hydrological manifestations specific of the northwestern territory of Romania are the floods with various geneses (pluvial, pluvio-nival, and more rarely, nival) and the high mountainside run-offs, generated by torrential rainfalls and by sudden defrosting. The maximal risk factors are considered to be the spring-summer floods, when the natural conditions are favorable for the incidence of catastrophic deluges, The damage produced during this period are much more serious than those which occur during the period of vegetation. However, the convective or front rains may also generate exceptional floods during the summer months. The risks caused by the floods are characteristic of the areas exposed to the advection of oceanic air masses from the west, amplified by the orographic configuration. Such areas are more exposed to the high risk hydrological phenomena, In the hills/ uplands, with frail lithologic substratum, low forestation and steep slopes, the hydrological risk factors are generated by torrential rainfalls, which cause violent mountainside flows. The effects are more than often destructive, resulting in human casualties and material damage. The mountainside flows generate material damage in agriculture, 1 Precipitation as a risk factor The risk factors generated by excessive precipitation have a serious impact on the natural and socio-economic environment from this part of Romania. © 2002 WIT Press, Ashurst Lodge, Southampton, SO40 7AA, UK. All rights reserved. Web: www.witpress.com Email witpress@witpress.com Paper from: Risk Analysis III, CA Brebbia (Editor). ISBN 1-85312-915-1