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| Titel |
Present and future water resources supply and demand in the Central Andes of Peru: a comprehensive review with focus on the Cordillera Vilcanota |
| VerfasserIn |
Fabian Drenkhan, Christian Huggel, Nadine Salzmann, Claudia Giraldez, Wilson Suarez, Mario Rohrer, Edwin Molina, Nilton Montoya, Fiorella Miñan |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250097595
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| Publikation (Nr.) |
 EGU/EGU2014-13194.pdf |
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| Zusammenfassung |
| Glaciers have been an important element of Andean societies and livelihoods as direct
freshwater supply for agriculture irrigation, hydropower generation and mining activities.
Peru’s mainly remotely living population in the Central Andes has to cope with a strong
seasonal variation of precipitations and river runoff interannually superimposed by El Niño
impacts. Direct glacier and lake water discharge thus constitute a vital continuous
water supply and represent a regulating buffer as far as hydrological variability is
concerned.
This crucial buffer effect is gradually altered by accelerated glacier retreat which leads
most likely to an increase of annual river runoff variability. Furthermore, a near-future
crossing of the ‘peak water’ is expected, from where on prior enhanced streamflow decreases
and levels out towards a new still unknown minimum discharge. Consequently, a sustainable
future water supply especially during low-level runoff dry season might not be guaranteed
whereas Peru’s water demand increases significantly.
Here we present a comprehensive review, the current conditions and perspectives for
water resources in the Cusco area with focus on the Vilcanota River, Cordillera Vilcanota,
Southern Peru.
With 279 km2 the Cordillera Vilcanota represents the second largest glacierized mountain
range of the tropics worldwide. Especially as of the second half of the 1980s, it has been
strongly affected by massive ice loss with around 30% glacier area decline until present.
Furthermore, glacier vanishing triggers the formation of new lakes and increase of lake levels
and therefore constitutes determining hazardous drivers for mass movements related to
deglaciation effects.
The Vilcanota River still lacks more profound hydrological studies. It is likely that its
peak water has already been or might be crossed in near-future. This has strong implications
for the still at 0.9% (2.2%) annually growing population of the Cusco department (Cusco
city). People mostly depend on these water resources but indicate a strong water vulnerability
due to a high degree of absolute poverty, 30% and only 67% of access to drinking water. The
Vilcanota area has been traditionally the breadbasket for the whole Cusco area.
While agriculture is the most important labor sector, a growing export-oriented crop
production depends highly on a minimum river streamflow ensuring sufficient water
quantity and quality. Hydropower, with 53% of the total electricity nationwide the
energy pillar of Peru’s economy, might also be heavily affected by diminishing
water resources. Nevertheless, improved power plants have to balance out Peru’s by
7.5% y-1 increasing energy demand. For instance, the Machu Picchu hydropower
plant is currently expanded by 100 MW to a full capacity of 190 MW but does not
consider future water availability of the Vilcanota River and local impacts for the
population.
Our conclusions suggest to focus on an integrative risk-oriented supply-demand water
balance model scheme in order to capture the complexity of recent and future water
distribution. The integration of both physical and social key variables considering long-term
changes in climate-glacier interactions as well as economic and demographic trends, plays a
determinant role for the performance quality of that model and future adaptation strategies. |
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