WIND IN VIPAVA WALEY – BURJA (BORA)Ajdovščina, July 3, 2013

BURJA - BORA

The strongest local wind in Slovenia. North, north-east wind, dry, gusty,

stronger more frequent in colder period of the year.

Bora in Vipava valley with gusts of up to 180km/h.

Formation of bora due to temperature difference and typical orography.

VIDEOS

Bora in Vipava Bora on Nanos Overturned truck Wind erosion Wind empties the garbage container Damage in the city March 10, 2010

MAIN PROBLEMS

Risk of human lifes.

Direct damage to the buildings, infrastructure.

Direct and indirect damage to agriculture.

Indirect damage due to closed schools, factories…

Indirect damage due to closed roads.

¸CLOSING THE ROADS

There are three types of roads: Major highway (DARS) Regional road Local roads

There are two systems of monitoring bora Burja (used for managing regional roads) SNVP (used for monitoring major highway)

The two systems are not sinchronised.

BURJA

Includes seven stations in Vipava walley

The central computer located in Ajdovščina

Four levels of road closer based on limit gust velocity

Type of closer

Critical gust velocity

Road closer for

Z1 80-100 km/h camper vans, refrigerator trucks and sheeted vehicles up to capacity of 8 t

Z2 100-130 km/h all sheeted vehicles and refrigerators; if the wind speed exceeds 110 km/h, the speed limit for all vehicles is 40 km/h

Z3 130-150 km/h all level II vehicles and buses

Z4 over 150 km/h all vehicles

SNVP

Includes nine stations. Central control station in Kozina (30 km

from Ajdovščina) Same criteria as in Burja system Different locations, different measuring

devices, different algorithm → differents measures.

AVAILABILITY OF THE DATA

Burja system Status

SNVP system Not publically available.