Abstract. The Norwegian Water Resources and Energy Directorate (NVE) have run a
national flood forecasting and warning service since 1989. In 2009, the
directorate was given the responsibility of also initiating a national
forecasting service for rainfall-induced landslides. Both services are part
of a political effort to improve flood and landslide risk prevention. The
Landslide Forecasting and Warning Service was officially launched in 2013 and
is developed as a joint initiative across public agencies between NVE, the
Norwegian Meteorological Institute (MET), the Norwegian Public Road
Administration (NPRA) and the Norwegian Rail Administration (Bane NOR). The
main goal of the service is to reduce economic and human losses caused by
landslides. The service performs daily a national landslide hazard assessment
describing the expected awareness level at a regional level (i.e. for a
county and/or group of municipalities). The service is operative 7 days a
week throughout the year. Assessments and updates are published at the
warning portal http://www.varsom.no/ at least twice a day, for the
three coming days. The service delivers continuous updates on the current
situation and future development to national and regional stakeholders and to
the general public. The service is run in close cooperation with the flood
forecasting service. Both services are based on the five pillars: automatic
hydrological and meteorological stations, landslide and flood historical
database, hydro-meteorological forecasting models, thresholds or return
periods, and a trained group of forecasters. The main components of the
service are herein described. A recent evaluation, conducted on the 4 years
of operation, shows a rate of over 95 % correct daily assessments. In
addition positive feedbacks have been received from users through a
questionnaire. The capability of the service to forecast landslides by
following the hydro-meteorological conditions is illustrated by an example
from autumn 2017. The case shows how the landslide service has developed into
a well-functioning system providing useful information, effectively and on
time.
The Norwegian forecasting and warning service for rainfall- and snowmelt-induced landslides