Water Governance in the Context of IWRM: Chile - Climate Change and Water Governance: Adaptive Capacity in Chile and Switzerland - page 153

Fig. 9.2 Evolution of temperatures at Visp according to A1B scenario for summer temperatures
( left ) and winter temperatures ( right )

where a lack of planning for drinking water supply has led to sector issues between
hydropower use, tourism use and drinking water supply (Reynard 2000a ) , as well as
tensions between the different sectors that arose in the 2003 summer heat wave,
despite a paradoxical increase in surface flows in the River Rhône due to enhanced
glacier melt.
The impacts of climate change may also compound the reduction in ecological
status of many surface waters in Switzerland. Of 65,300 km of surface waters in
Switzerland, 10,600 km have been considerably altered through technical projects,
thereby impairing their ecological functions (FOEN 2009 ) . Hydro-peaking (arti fi cial
high and low flow phases) also impacts rivers, in that they regularly dry up from
over extraction of water, with damaging impacts on aquatic ecosystems. It is also
worth mentioning the potential impacts of climate change on mountain forests,
which have a variety of highly significant environmental benefits, including the
protection against natural hazards (Gautam et al. 2004 ) . Increasing temperatures
and lower precipitation levels during the hottest periods are likely to lead to greater
risk of forest fires, further increasing the vulnerability of mountain communities to
the mounting hazards (rock falls, flash floods, landslides) from which they normally
provide protection (Gautam et al. 2004 ) .
Climate model data from the ACQWA project was used to calculate return peri-
ods as per A1B and B2 emissions scenarios. A synthesis of results from the stations
at Visp and Zermatt are detailed below (Fig. 9.2 ). The figures show an evolution of
higher mean temperatures for both summer and winter periods, with corresponding
impacts on glacier melt that will influence the run off regime of the Rhône based as
depicted in Fig. 9.1 above.

9.1.1 Focusing Events

To date, the Valais has been more seriously impacted by extreme precipitation
events and flooding than by situations of drought and scarcity. Drought impacts
were viewed by stakeholders as being relatively minor while extreme weather