Water Resources Management in Peru - Potential Climate Change Effects

Potential Climate Change Effects

Although a thorough assessment of the net impacts on Peru's water resources is still lacking, some trends are discernible. The effects of climate change in Peru include more extreme weather conditions such as droughts and floods, El Niño Southern Oscillation, increased likelihood of flash fires, changes in the ability of ecosystems to store water, and the retreat of Andean glaciers. The effects of glacier retreat are different at the initial and final stages of glacier retreat—initially more water is available during the dry season, while flow declines below the initial level once the glacier has melted. (See Impacts of Glacier Retreat in the Andes:Documentary). High mountain ecosystems, including páramos (unique wetlands of the Northern Andes) and snowcapped terrains are among the environments most sensitive to climate change. These ecosystems have unique endemic flora and provide numerous valuable environmental goods and services. Data recently made available suggest that climate impacts have already altered the circulation patterns responsible for producing and moving water vapor to the region. These changes have likely contributed to the disappearance of high-altitude water bodies, as well as to the increased occurrence of natural and human-induced mountain fires.

The Program for Strengthening of National Capacities to Manage the Impact of Climate Change and Air Pollution (PROCLIM) together with the Ministry of Environment and the Netherlands Cooperation Agency published a model for adaptation that estimated the impacts of climate change climate for several river basins. For instance, in the Mantaro River Basin one scenario presents a possible increase (greater than 50%) in precipitation along the entire basin, particularly over the west central mountain range and the Chinchaycocha plateau. According to a second scenario, precipitations in the west central range could increase in more than 100% while in the eastern region they could be reduced by 20%. In the Piura River Basin there is a (i) tendency towards increase of the minimum temperature peaks and the average sea level; (ii) greater probability that the intensity of future El Nino Events will increase; (iii) there will be an occurrence of an El Nino Phenomena during the 2009–2015 period similar to the one of 1982–1983; (iv) a deficit in the balance of water is foreseen during the period 2005–2035; and (v) tendency towards lengthier and more frequent drought periods is noticeable. In the Cordillera Blanca, Santa River Basin precipitations will become the main water resource in view of the severe retreat of the area's tropical glaciers. Because of the tendencies towards temperature increase, it is expected that the runoff levels will increase until they reach a peak in the first half of the century, to then exhibit a sustained decline in water resources.