to the poor of food. Interactions will be stronger in the poorer and drier regions of the basin. Food security is also fundamentally dependent on an efficient transport
infrastructure for agricultural imports and access to markets and is thus highly sensitive to transport disruption. Food security is also one of the key factors underpinning health and
wellbeing. The interaction of water, health, energy and food securities will determine
health and wellbeing, the potential for economic development, cooperation or conflict and human mobility within the region. Agricultural intensification to increase regional and
global food security has the potential to significantly impact downstream water quality.
Climate change and Brazil’s global food basket
Brazil is often considered the world’s breadbasket and has long been a leading exporter of the world’s breakfast foods orange juice, coffee, sugar and cocoa. Latin America’s largest
economy is now also a leading producer of grains and meat the world’s largest beef herd,
sugar half the world’s sugar market, corn the third largest global exporter, soybeans second only to the USA, timber and pulp, cotton the fourth largest producer globally,
tobacco world’s largest producer and ethanol world’s largest exporter. Blessed with land
and a good climate and significant increases in productivity resulting from the application of technology, Brazil is now an agricultural superpower. This means that threats to the
Amazon and particularly to those parts of the Brazilian Amazon that form part of this ‘agricultural miracle’ or those areas outside the Amazon that may be affected by regional
climate change as a result of environmental change in the Amazon are threats to global
food security with potential impacts on availability and prices worldwide. Moreover the water, energy and agrochemical investment that has been necessary to increase
productivity - and which threatens water security downstream of these areas - must be
maintained if this production is to be maintained. The offsite impacts of these, sometimes unsustainable, investments need to be minimized and the eco-efficiency of agriculture
maximized in order to ensure that this level of production is robust and environmentally
sustainable.
Case studies illustrating threats to water security in the Amazon
1. The status of dams in the Amazon and their downstream impact
Currently, less than 10 Tollefson, 2011 of electrical power or 15 of Brazil’s domestic energy supply for 2010 da Silva Soito and Freitas, 2011 comes from dams in the Amazon.
However, to meet the increasing energy demands of Brazil, there are plans for the development of around 150 new dams in the Amazon basin, including the highly
controversial Belo Monte dam on the Xingu river which is expected to be one of the worlds largest dams when completed in 2015 Finer and Jenkins, 2012; Tollefson, 2011. Finer and
Jenkins 2012 carried out an assessment of the ecological implications of building these dams and found that nearly fifty per cent would have high impact defined as scoring
positive on three out of five factors of dam impacts. Most of the new dams will cause fragmentation breaking connectivity between protected Andean headwaters and the
lowland Amazon rivers and deforestation, and over 80 of the dams would further drive
deforestation as a result of road building, transmission lines and displacement associated with inundation. While many studies focus on the impacts on water quality, particularly
ecological quality Fearnside, 2001; Viana, 2002; Finer and Jenkins, 2012 of these dams, very few consider the downstream impacts on water resource quantity. This is partly
because many of the planned projects are run-of-the river type dams that do not impact
downstream water resources significantly. However, some are reservoir dams and increases in downstream dry season flow as well as 1-2 month earlier occurrence of peak floods have
been observed by Viana 2002 in the Jamari river downstream of the reservoir dam. This
change is attributed to storage and releases associated with HEP production. The Amazon is relatively un-impacted by large dams compared with many areas globally
Tollefson, 2011. Of the more than 36,000 large dams in the world, the Amazon has only 133 according to Mulligan et al. 2011b. These are largely distributed outside the
watershed in the east of Brazil, though there are a number also in sub-basins in the SE of the Amazon watershed and in the upper reaches of the basin in Peru and Bolivia Figure
34. There are, however plans for more than at least 110 and possibly 150 new dams, some
of which are already under construction. If all are built the Amazon would then be home to at least 243 large dams, again largely in the S and E of Brazil in order to provide water for
agricultural irrigation in the dry season and for domestic use but also a number of large
HEP projects in Peru, Bolivia, Brazil, Ecuador and Venezuela. These dams will bring significant benefits to the region but are themselves threatened by the impacts of upstream
land use change and of climate change. They also threaten the resources available to
downstream users and this competition for resources may become a source of conflict in the border regions of Peru and Bolivia where many of the new dams are planned. Similarly,
national conflicts between the Brazilian states may results from these developments. In a region with as plentiful water resources as much of the Amazon basin, the impacts of
dams on available water downstream are unlikely to be significant since dam storages will be very low in comparison with the volumes of water passing through the river systems.
Impacts of dams on sediment retention are also likely but again the volumes will be small
in comparison with the total volumes of sediment and organic matter carried by these river systems. Indeed substantial sedimentation by dams would soon render the dams
disfunctional so large-scale sediment retention is unlikely to occur for well-designed dams.
The greater risk of continued dam development is economic rather than environmental: i.e. that significant financial resources will be placed into constructing infrastructure which,
because of the large volumes of sediment carried by and great flow variability of these
rivers, will render the dams inefficient and expensive in operation and with a short useful life, especially if landscapes in the watersheds of these dams are not well managed.
Figure 34: Current large dams by major sub-basin
Figure 35: Current and planned large dams by major sub-basin
2. The water security impacts of the Amazon droughts of 2005 and 2010
