Waterways from glaciers to coastal waters in Iceland. Jórunn Harðardóttir, IMO Nordic WFD conference September 26, 2012

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2 Waterways from glaciers to coastal waters in Iceland Jórunn Harðardóttir, IMO Nordic WFD conference September 26, 2012

3 What to include and what not to include? Hydrology of Iceland Much on glaciers and rivers Little on groundwater Nothing on lakes and coastal waters Main focus What differs from other Nordic countries? What will the future bring us? 3

4 Hydrology of Iceland Main influences Location Meteorology Bedrock type Glaciers Snow influence Vegetation Soils Land-use 4

precipitation, especially in the south Very variable meteorological

5 Hydrology of Iceland Location and Meteorology Maritime conditions Mild summers and cool winters Frequent cyclonic activity; Iceland Low High precipitation, especially in the south Very variable meteorological conditions during all seasons Freezing-thawing cycles, winter floods Crochet,

6 Hydrology of Iceland Geology Tertiary basalts in the East and West Little infiltration causes abundant direct runoff rivers Volcanically active zone Young (postglacial) lava fields with high permeability Limited surface runoff Spring-fed rivers at the boundaries Direction of groundwater and surface flow Strongly controlled by local tectonics, volcanic formations and glacially scoured landforms 6

7 Hydrology of Iceland Groundwater 7

8 Hydrology Groundwater Total groundwater >1000 m 3 /s, of which 400 m 3 /s in lowlands About 20% of runoff in Iceland About 20% of used hydropower About 97% of drinking water Energy carrier for all geothermal power Few countries have as great abundance of groundwater as Iceland 816 L /per person/day 8

Hydrology of Iceland Glaciers Glaciers cover approximately 11% of Iceland Account for 35 m thick layer of ice if spread out evenly Store 15-20 years of total annual average

9 Hydrology of Iceland Glaciers Glaciers cover approximately 11% of Iceland Account for 35 m thick layer of ice if spread out evenly Store years of total annual average precipitation Account for 1 cm increase in global sea-level rise if melted Largest rivers in Iceland are of glacial origin, although most rivers are of somewhat mixed origin Photo: Ira Goldstein 9

LVL [cm] Hydrology of Iceland Glacial rivers jökulhlaups Frequent jökulhlaups in glacial rivers Many causes: Subglacial geothermal melting and volcanic eruptions, drainage of proglacial lakes

10 LVL [cm] Hydrology of Iceland Glacial rivers jökulhlaups Frequent jökulhlaups in glacial rivers Many causes: Subglacial geothermal melting and volcanic eruptions, drainage of proglacial lakes Water level rose 5 m in 6 min 500 V414.W.W1.A Múlakvísl, 9. July 2011 Photograph, Gunnar Sigurðsson :00 05:00 06:00 07:00 Time t 10

Hydrology of Iceland Glacial rivers sediment transport Suspended sediment transport extremely high in individual rivers Up to 8 10 6 yr -1 Similar to sediment load in many of the great Russian rivers

11 Hydrology of Iceland Glacial rivers sediment transport Suspended sediment transport extremely high in individual rivers Up to yr -1 Similar to sediment load in many of the great Russian rivers Pechora, Yenisei, and Lena t yr -1 For the 32 rivers shown here, suspended sediment transport is about t yr -1 Sediment transport in jökulhlaups is not included Often t in individual jökulhlaups About t in the 1996 jökulhlaup Vatnajökull 11

direct runoff rivers High-volume floods are often caused by high

12 Hydrology of Iceland Snow Snow cover influences run-off greatly Acts as water depository in winter Snow melting greatly affects discharge in direct runoff rivers High-volume floods are often caused by high temperature, rain, and snow melt, usually in spring but occasionally during winters RAX 12

13 Hydrology of Iceland Runoff seasonality and river types 60% Direct runoff rivers 20% Glacier fed rivers 20% Groundwater fed rivers

14 Hydrology of Iceland Soil, vegetation, land-use Vast areas non- or scarcely vegetated Wetlands abundant Volcanic soils Easily erodable Store immense amount of water Maps from the Agricultural University of Iceland website 14

15 Hydrology of Iceland One of many classifications of Icelandic water based on e.g. river type, regulation, temperature The complex combination of all these beforementioned factors create the unique environmental setting for the aquatic biota discussed in a later talk Freysteinn Sigurðsson et al.,

16 Waterways in Iceland Future changes? Icelandic glaciers are retreating rapidly! Glacier termini variations Lowering of Snæfellsjökull

17 Future changes? Glacier retreat Sólheimajökull 1997

18 Future changes? Glacier retreat Sólheimajökull 2006

19 Future changes? Glacier retreat Sólheimajökull 2010

20 Future changes Glacier retreat and discharge Glacier retreat Greatly affects glacier river discharge Causes modification/deflection of river channels Photo RAX 20

21 Runoff maps vs mm/year or 4770 m 3 /s 1900 mm/ári eða 5900 m 3 /s 25% increase from to Jónsdóttir, 2008 Jónsdóttir, 2007

river Temperature increase of ~2 o C Precipitation increase of ~3% Glacier fed river

22 The effect of climate change on runoff in Iceland Changes in discharge seasonality in compared to considering the emission scenario A1B Direct runoff river Temperature increase of ~2 o C Precipitation increase of ~3% Glacier fed river Temperature increase of ~2 o C Precipitation increase of ~16% Einarsson & Jónsson,

23 The effect of climate change on runoff in Iceland, conclusions There will be large changes in runoff seasonality Mainly caused by changed snow seasonality Runoff from the glacier will increase by up to 50% due to increased snow and ice melting Duration of glacier runoff is predicted to increase by nearly two months, reaching further into the spring and autumn Compared to the period , a warming of about 1 o C has already been observed during the period Causing considerable discharge changes in the same direction as the predicted future changes The runoff change may be important for the design and operation of hydroelectric power plants, transportation, tourism and other utilization of water There is a large uncertainty associated with differences between the climate development as modelled by different GCMs and RCMs

24 Direct runoff river Photo, JH Highland lake Photo, JH Groundwater fed & glacial rivers Photo, Oddur Sigurðsson Coastal setting Photo, JH 24

The impact of climate change on glaciers and glacial runoff in the Nordic countries

The impact of climate change on glaciers and glacial runoff in the Nordic countries Tómas Jóhannesson, Guðfinna Aðalgeirsdóttir, Andreas Ahlstrøm, Liss M. Andreassen, Stein Beldring, Helgi Björnsson, Philippe