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THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS. Andy Chan Geo 387H Physical Climatology Fall 2007. Glacier Related Excerpts from IPCC Assessment Report 2007. More than 1/6 of world population depend on snowmelt- or glacier-fed rivers
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THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS Andy Chan Geo 387H Physical Climatology Fall 2007
Glacier Related Excerpts fromIPCC Assessment Report 2007 • More than 1/6 of world population depend on snowmelt- or glacier-fed rivers • Glaciers continue to melt as temperature continue rises • Some glaciers will be depleted in a few decades, some within this century • Reduce water availability for irrigation and agriculture ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Why Himalayas? http://www.enchantedlearning.com/asia/riveroutlinemapanswers ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Why is it important? • Himalayas is nicknamed “Water Tower of Asia” • Largest body of glaciers outside of polar regions, occupy 17% of mountain area • Glaciers supply freshwater to 500 million people in Himalaya-Hindu-Kush region and 250 million people in China (IPCC) ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Why is it important? IPCC Assessment Report 2007 Figure 10.4 ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Literature Reviewed Reviews in Nature • Barnett, Adam, Lettenmaier (2005) Modeling • Singh and Kumar (1997) • Singh and Bengtsson (2004) • Singh, Arora, Goel (2006) • Rees and Collins (2006) ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997) • 10071 km2 • Elevation 2900 to 7000 m • Most area under 6000 m • ~2.5% covered by glaciers • ~45% runoff from snow and glacier melt ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997)Snow Water Equivalent (SWE) ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997)Snowmelt Runoff ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997)Glacier Melt Runoff ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997)Total Streamflow Runoff ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Kumar (1997)Keypoints • Snowmelt and glacier melt increases linearly with temperature rise • Snowmelt runoff, glacier melt runoff, and total streamflow increased 4-18%, 33-38%, and 6-12% respectively in +2°C scenario • Higher streamflow in the spring ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Bengtsson (2004) • 22275 km2 • Elevation 500 to 7000 m • Most area under 6000 m • ~11% covered by glaciers • ~60% runoff from snow and glacier melt ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Bengtsson (2004)Monthly Snowmelt Runoff ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Spring: +12.1% Summer: -10.4% Annual: -6.1% Singh and Bengtsson (2004)Snowmelt Seasonal Change ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh and Bengtsson (2004)Monthly Streamflow ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Spring: +4 to +10% Summer: -6 to -11% Annual: -4 to -6% (due to predicted decrease in rainfall) Singh and Bengtsson (2004)Counterbalance ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Reduced contribution of snowmelt from lower part of the basin is counterbalanced by the increased glacier melt from upper part of the basin Singh and Bengtsson (2004)Streamflow Seasonal Change 2 3 ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
In a large basin with a wide range of elevation, spring runoff increases and summer runoff decreases Both caused by early snowmelt Snowmelt reduction in the lower zone counterbalanced by increased glacier melt from the higher zone Annual snowmelt decreases by 4-6% (+2°C ) due to basin-wide deduction in snowmelt and rainfall Singh and Bengtsson (2004)Keypoints ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh, Arora, Goel (2006) • 16.13 km2 • Elevation 3950 to 5800 m • ~60% covered by snow and ice • ~83% runoff from glacier melt • ~17% runoff from rainfall ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh, Arora, Goel (2006)Change in Basin Runoff ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Singh, Arora, Goel (2006)Change in Basin Runoff in the Summer ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
In a basin with 87% glacier melt as total runoff, +2°C increases summer streamflow by 28% Singh Arora, Goel (2006)Keypoint ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Rees and Collins (2006) • Two Conceptual basins • SE Himalayas: Monsoon rain • NW Himalayas: Westerly precipitation • 5000 km2 each • 50 km2 of glacier • Elevation 4000 to 6000 m ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Rees and Collins (2006)Hypothetical Catchment ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Rees and Collins (2006)Ice Cover Area in 150 Years ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Rees and Collins (2006)Discharge in Future 150 Years Western Catchment Eastern Catchment Baseline Condition Warming Condition ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Discharge increases by 150-170% before dropping by 33% and 4-18% in the Western and Eastern catchment respectively Rees and Collins (2006)Keypoint ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H
Wrapping up… Short term • Temperature rise causes streamflow to increase in spring and decrease in summer • Water demand is highest during summer • Reduced contribution of snowmelt from lower elevation is counteracted by increased glacier melt from higher elevation Long term • Streamflow initially increases as glaciers melt, then decreases when glaciers are depleted ANDY CHAN - THE IMPACT OF CLIMATE WARMING ON THE HYDROLOGY OF GLACIER AND SNOW MELTING IN THE HIMALAYAS - PHYSICAL CLIMATOLOGY - GEO387H