Water and Climate Change Slobodan P. Simonovic Professor, Department of Civil and Environmental Engineering Director Engineering Studies, Institute for Catastrophic Loss Reduction The University of Western Ontario

Main messages Climate change is hydrologic change Water is embedded in everything we do London will see more floods in the future What can we do? Manage our water wisely Be green in your yard Use water efficiently Reduce, reuse and recycle Innovation 2

Hydrologic – water cycle Innovation 3 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 4 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 5 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 6 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 7 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 8 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 9 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 10 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 11 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 12 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic – water cycle Innovation 13 Evaporation Transpiration Sublimation Condensation Advection Precipitation Surface Runoff Melt Runoff Infiltration Groundwater Flow

Hydrologic cycle and climate Innovation 14 Each element of the Hydrologic Cycle is affected by changing climate Watershed/River Basin/Aquifer/Global Water is the delivery mechanism for many of the impacts of climate change

Hydrologic cycle and climate Innovation 15

Hydrologic cycle and climate There are general indications that: the present mid-latitude rain belt would shift northward; snowmelt and spring runoff would occur earlier than at present; evapotranspiration would be greater, as it would start earlier and continue longer; temperature will increase; …. Innovation 16

Hydrologic cycle and us We take water for our needs Water supply Irrigation Industrial use … We change land use We pollute water “available water is a function of both quantity and quality…..poor water quality can render water unavailable for many uses.” …. Innovation 17

Hydrologic cycle and us Innovation 18

Hydrologic cycle and us Innovation 19

Hydrologic cycle and us Innovation 20

Consequences Innovation 21

Friday Forum 22Simonovic February 2009

Friday Forum 23Simonovic February 2009

Consequences Use of Great Lakes water for drinking Over 29 million people (8 million Canadians) depend on the lakes for drinking water. The quality of the water is already under stress. The average temperature in the Great Lakes basin could go up by about 4.5°C by Higher rates of evaporation and drier soils would reduce runoff. Water levels in the Great Lakes could fall by an average of between 0.5 m and 1.0 m. Innovation 24

Consequences Water quality might also be affected in the following ways: the dredging needed to offset lower water levels could resuspend toxic chemicals; higher water temperatures could decrease dissolved oxygen levels and increase the growth of algae and bacteria; less runoff and stream discharge would reduce the flushing out of bays and dilution of organic matter and chemicals; lower water levels could cause the disappearance of wetlands, which are valuable habitats; agricultural and urban expansion would continue to contaminate runoff with fertilizers and toxic chemicals. Innovation 25

What can we do? Manage the water resource more effectively: to accommodate to its natural variation to cope with the demands of a growing population to be prepared for changes in the water supply induced by climate change and to conserve water quality and quantity. Innovation 26

What can we do? Increase our flood resiliency: continue to improve forecasting and warning systems, and evacuation and relief plans; evaluate and improve existing flood-control structures; and design new structures to handle more frequent and extreme events. Innovation 27

What can we do? On personal level Use water efficiently to reduce the current 335 litres per person use 35% bathing 30% toilet flashing 25% laundry and cleaning 10% cooking and drinking Be green in your yard Do not buy bottled water Reduce, reuse and recycle Innovation 28

Can we meet the challenge? Climate change is hydrologic change Hydrologic variability affects terrestrial and aquatic ecosystems Hydrologic variability affects watershed services and human uses Water is embedded in everything we do We must work together to find solutions Innovation 29