Figure 36: Per-cent of major sub-basin converted during the period 2004-2012 according to terra-i
Terra-i Reymondin et al, 2012 uses learning algorithms to identify land conversion from forest using MODIS vegetation index data on a 16-day basis. Data for Jan 2004 - May 2012
are used here Figure 36 to understand the rates of recent forest conversion by major sub- basin. These data may still contain small-scale artifacts resulting from clouds and riparian
flooding but are well validated within this region. Clearly most recent change has occurred in S and E Brazil, Bolivia, upland catchments in Peru and SE Colombia. Deforestation is
as high as 26 on a sub-basin level over the 8.5 years.
4. Mining and oil and gas development
The Amazon is an area with considerable potential for mining and oil and gas which will bring both significant benefits but also significant risks to people in the region. Mining
activities in the Amazon already have a significant impact on water quality in the areas
affected. The Tapajos river basin of Para, Brazil is host to hundreds of thousands of artisanal small-scale gold miners who use mercury amalgamation to recover gold with
substantial amounts of mercury polluting the local ecosystem de Sousa., 2010. Large
quantities of mercury-rich sediments have been shown to leak into surface waters with serious health impacts for humans Berzas Nevado et al., 2010. As well as a direct effect on
water quality from the small-scale gold mining, mining activities indirectly impact water
resources through the development of infrastructure causing widespread deforestation. Swenson et al., 2011 estimated that between 2003 and 2009 in the Madre de Dios region
in the Peruvian Amazon, 6,600 ha of primary tropical forest was converted to mining ponds and tailings with mining-related deforestation increasing markedly over time and
outpacing settlement-related deforestation. Oil and gas exploration may be an even greater
threat to Amazon water security. In recent years, nearly fifty per cent of the Peruvian Amazon was designated oil and gas concessions with 17 of them overlapping protected
areas Finer and Orta Martinez, 2010. Such large scale oil exploration and associated
deforestation may have great impacts on water quality and water quantity in the region. The current distribution of large mines by major sub-basin is shown in Figure 37 indicating
most activity in Venezuela, Guyana, Suriname and French Guiana but also the montane
areas of Ecuador, Peru and parts of Bolivia. The future of mining in the region is indicated by Figure 38 which aggregates the mining concessions of the region by major sub-basin.
Extensive areas up to 100 of entire sub-basins of the Andes and of the north and eastern Brazil are under mining concessions which could be made operational. Data for Venezuela,
Guyana, Suriname and French Guiana are much less robust and the authors suspect there
are more concessions in those countries than are available in the public domain.
Figure 37: Number of current large mines by major sub-basin
Figure 38: Fractional coverage of mining concessions by major sub-basin
Petroleum brings significant economic resources to the countries of the Amazon and is likely to continue to do so into the future. Figure 39 shows the current distribution of oil
wells by sub-basin with a clear concentration in Ecuador and S Colombia, N Peru and S Bolivia as well as some sites in W Brazil. Most of Colombia and Venezuela’s Oil and Gas
fields are outside the Amazon. Figure 40 records the known oil concessions as fractional coverage of the basin, indicating significant further development potential in Peru,
Ecuador, Bolivia and Colombia up to 100 of entire basins covering most of Ecuador and
Peru. The mining and oil and gas concessions hardly overlap but between them cover most of the basin. Development will have to be carefully managed and regulated to avoid serious
environmental and water resource degradation. The current and historic record in this
regard for both mining and oil and gas is not a good one in the region and so these developments may present the most important threat to water security in the region.
Figure 39: Number of current oil wells by major sub-basin
Figure 40: Fractional coverage of oil and gas concessions by major sub-basin
A WaterWorld analysis of the impact of converting only 1 of the oil and gas concession area in Ecuador and northern Peru to oil production, indicates that this would increase the
HF pollution index by between 0.5 and 2 for all catchments on a sub-basin level Figure
41. Impacts are much greater at the local scale at or immediately downstream of installations but will even have an impact regionally.
Figure 41: Pixel-scale left and sub-basin scale right increase in HF pollution index resulting from operationalisation of 1 of oil and gas concessions
A further analysis of the impact of converting 10 of the mining concession area in Ecuador and northern Peru only some of which is within the Amazon watershed to mining,
indicates that this would increase the HF pollution index by between 5 and 10 for many of the upland catchments on a sub-basin level Figure 42. Impacts are much greater at the
local scale at or immediately downstream of mines. There are also significant changes in
soil erosion resulting from these impacts, including in the watersheds of current and proposed dams.
Figure 42: Pixel-scale left and sub-basin scale right increase in HF pollution index resulting from operationalisation of 10 of mining concessions
5. Infrastructural threats to water quality in the Amazon
