engleski

Qualitative Assessment of Geohazard in Rječina Valley

Rječina watercourse is 18.7 km long. It spring is placed in the foot of the Gorski Kotar mountains, and its rivermouth is placed in the center of the city Rijeka. Riječina river valley extends through three distinctive geomorphological units. The upstream part of the river is placed in relatively wide valley, formed in paleogene flysch rocks. The central part of the watercourse is a narrow flysch valley, which is a part of a karst plateau, composed of Upper Cretaceous and Paleogene limestones. Downstream part of the watercourse flows through deep canyon cutted into the Cretaceous and Paleogene limestone rocks. The central part of the watercourse, between the Valići dam and the beginning of the canyon part close to Pašac, is 1.8 km long, and 0.8 to 1.1 km wide between the opposite slopes. This is the most unstable part of the wide area of Rijeka with the high degree of geohazard. Mass movements are mostly occurring on the contact of fractured, and karstified carbonates and flysch rock complex. In that above mentioned, central part of the valley, that is in its south-western part, two large rock falls of limestones were recorded. In the northeast part of the valley, a complex landslide is active. Different types of movements can be distinguished in it: sliding of slope deposits over the flysch bedrock, toppling of limestone blocks and rock falls from cliffs.

karst ; geohazard ; slope ; river valley

nije evidentirano