BASE_book_RZ_2712_screen

Flood in Kalajoki
river basin in
August 2012
caused significant
crop damages
Photos: North Ostrobothnian ELY-centre
The Climate
Challenge
The Kalajoki river basin
is a typical Finnish flood
risk area that faces the
interdependent challenges
of managing flooding,
caused by snowmelt, heavy
rains and ice dams, as
well as poor water status,
originated mainly from
agricultural activities in the
river basin. Seasonal changes
in discharges in Finland are
the most distinct anticipated
impacts of climate change.
Changes in precipitation
and temperature may also
increase the nutrient load
from catchments to water
bodies in future climate.
The Kalajoki is a midsize
lowland river that
is surrounded mainly by
rural land. Currently, 80%
of the land in the basin is
woodland and peatland and
approximately 15% is used
for agriculture. Some 48,000
people live in the basin.
The case study focused on
the Ylivieska-Alavieska
region within the Kalajoki
basin. This area has been
nominated nationally as a
significant flood risk area.
Presently, there are in total
620 inhabitants, 530 buildings
and 3 vulnerable sites (e.g.
hospital) in the area that
are at risk in the case of
an extreme flood. Most risk
sites in the study area are
protected by embankments,
however, an extreme
weather event that exceeds
the capacity of the embankments
multiplies the
estimated damage costs
to EUR 15-25 million.
Flooding also increases
nutrient loading and suspended
solids to watersheds,
especially during summer
and autumn floods when
the land is unfrozen.
64 water resources & health