L. 9: Using Climate Projections for Water Management, C. 8-Milly

Question 1

Climate Projections

Answer 1

12. Mitigation measures can reduce the magnitude of impacts on water resources, in turn reducing adaptation needs.
13. Water resources management impacts on many other policy areas.
    - - Warming adds major pressure to nations that are already confronting sustainability freshwater use issues. The challenges are: having too much water, having too little water, and having too much pollution.

Question 2

World population and climate change

Answer 2

• • Project needs for 50 years because beyond that too uncertain, infrastructure lasts 50 years.
• • World population growth most in Asia, India, Africa, areas with most water stress right now. Also in areas of U.S. (south).

Question 3

Characteristics of water-stressed areas

Answer 3

High population and growth.
Arid to dry and hot.
Few water resources.
More demand for water, more waste.

Question 4

water use

Answer 4

Most in agriculture, industry.

Most countries don’t have info. on how wastewater is being treated and used.

Question 5

Climate change impacts on future water resource management

Answer 5

Will have to use more groundwater resources; infrastructure will decline; less reservoir carryover because of increase in demand; less flexibility in dryer periods; peak flow earlier.
Sea level rise–more flooding and salinity inflow.
Affects the function and operation of
existing water infrastructure – including hydropower,
structural flood defenses, drainage and irrigation systems.
Climate change challenges the traditional assumption that past hydrological experience provides a good guide to future conditions.
Adaptation options designed to ensure water supply
during average and drought conditions require integrated demand-side as well as supply-side strategies.

Question 6

Stationarity

Answer 6

Milly: have we stepped outside the boundary of natural variability?
Water management planning and design should no longer rely on stationarity, an assumption that future water-related variables will lie within an unchanging zone of variability that we can determine from past records. Climate change is altering the means and extremes of precipitation, evapotranspiration, river discharge rates and runoff, rendering models based on a stationarity assumption invalid. Future water conditions will not look like the past. Combine historical records with climate projection models.