Changing Glaciers and Hydrology in Asia - Environmental Health at ...

and China (Figure 3.13 on page28). Thresholds of water scarcityhave been defined to describethe different levels of waterstress and potential levels ofneed. In Figure 3.13, a waterstress threshold has been definedas 1,000 m 3 per person per year;below this threshold, populationsare defined as being under“water stress” conditions. Thisthreshold serves as a warningsign to places expected toexperience population growth,increases in future water demandfor agriculture or industry, andvulnerability to potential impactsof climate change.Figure 3.9. A closer look at the total fertility rate in South andCentral Asia. See Figure 3.1 for country boundaries and basinnames. Data source: Includes surveys from India 1998-1999, Nepal2001, downloaded from measuredhs.com April 2010.The three panels of Figure 3.13 show, from top to bottom, scenarios of water stress conditionsin 2030 under climate change only, under population change only, and then with both climatechange population changes. In thelatter two scenarios, water stressconditions are projected to spreadto Pakistan, India, and most countriesof Southeast Asia. Under waterstressedconditions, irrigation will beless and less viable as time goes on—another threat to food security andhealth.Figure 3.10. Density of the population of young children in thearea. See Figure 3.1 for country boundaries and basin names. Mapshowing the total population count per pixel (2.5 minuteresolution or roughly 5km x 5km pixel). A standard deviationstretch is used, meaning that classes are created around the meanbased on the number of standard deviations (in this case, 2). Theintention of this graphic is merely to show magnitude, high (red)to low (green) of population. Data source: CIESIN, ColumbiaUniversity 2005.34