Water Governance in the Context of IWRM: Chile - Climate Change and Water Governance: Adaptive Capacity in Chile and Switzerland - page 152

Fig. 9.1 Taken from Beniston et al. ( 2011 ) showing projected developments of flooding and
drought instances for the Rhône Basin
more marked increase in summer temperature, higher precipitation that is more
intense during winter, but likely to be much reduced in summer months (Beniston
2006 ). Increased temperatures will continue to have a significant impact on the
melting of glaciers, whose thickness has already decreased by roughly five times
more in the period 1980-2000 than during average loss (Büchler et al. 2004 ) .
It has been suggested that the largest source of vulnerability from climate change
is likely to come from changes in the intensity or frequency of extreme events, such
as heat waves (winter and summer), heavy precipitation events and drought (Beniston
et al. 2007 ). Increased glacial melt also is leading to an increase in flood risks and
other natural hazard events (OcCC 2008 ) . Figure 9.1 represents the difference in
seasonal distribution of run off for the River Rhône between baseline values (1961-
1990) and projected values for A2 SRES scenario (800 ppm) by 2100. The dark
black line represents baseline run off, showing typical seasonal flows (high run off
in summer, low in winter) for an alpine regime. The dashed line shows the 2100
projection, with increased run off during early spring and decreased run off in mid
to late summer, while the dotted line indicates the intermediate alterations projected.
The graph suggests that summer months could experience enhanced drought situa-
tions through reduced glacial mass and precipitation, while in winter months
increased intense precipitation periods could not only impact on flood risk, but a
wide range of geomorphological processes such as landslides and rock falls.
Increased flooding and extreme precipitation events are compounded by an
increase in risk exposure due to infrastructure/housing development in vulnerable
areas which are currently seen as 'safe' due to technical interventions. Temperature
increases at alpine elevations raises demand for water uses such as artificial snow
making and summer cooling and drinking water leading to complex management
shifts, compounded by changes in seasonality. There have already been examples