Figure 8: As water is extracted and used along the supply chain, both the quality and quantity of water available is reduced.
flora and fauna that are crucial in the natural cycling of these ecosystems, thus ensuring their long-term function. Indeed, many rivers are straight- ened and wetlands and marshes drained or dried out behind dikes to ensure agricultural expansion, however, this invariably causes higher water velocity, higher risk of floods, and increased organic pollution further downstream (Bruijnzeel 2004; UNEP, 2005). These ecosystems also help buffer global climate change (Nepstad 2007). Hence, restoration must not address the catchments in terms of forests and riverine vegetation including ground layer, but must also ensure the natural meandering pathways and the flood marshes and wetlands to ensure proper filtration and buffering mecha- nisms against extreme flows. Worldwide, nearly 900 million people still do not have access to safe water (UNDESA 2009)
Global water withdrawal percentage by sector
Waste water discharge
Contaminated food provision
Reusing processed sewage
Drinking water treatment Sewage sludge
Restoration to re-establish diverse grazing and cropping systems, partially restoring naturally supplementing plants and trees in more diversified crop- ping and grazing systems, combined with green technology in irrigation efficiency, could help drastically reduce the 70–90% of the water currently consumed and partly wasted by agriculture. This, in turn, would increase water availibility to cities, improve water quality, as well as make more water available for irrigation. Such cropping systems capture more water through wetlands, marshes and lakes during flood seasons, rather than this causing floods and marine pollution as a result of seasonally extremely high veloc- ity and volume. This is particularly important for countries like Pakistan, where a near doubling in population from 184 million people in 2010 to a projected 335 million people by 2050 (UN population division, 2007) – and already facing water scarcity and flood challenges. Pakistan is one of many states that will need to address new ways to secure sufficient water supply for upholding food security in the future.
Ecosystem degradation
Restoration is financially viable (TEEB, 2009): Cities like Rio de Janeiro, Johannesburg, Tokyo, Melbourne, New York and Jakarta all rely on pro- tected areas to provide residents with drinking water. They are not alone – a third of the world’s hundred largest cities draw a substantial proportion of their drinking water from forest protected areas (Dudley and Stolton 2003). Forests, wetlands and protected areas with dedicated management actions often provide clean water at a much lower cost than man-made sub- stitutes like water treatment plants for example in Venezuela: the national protected area system prevents sedimentation that if left unattended could reduce farm earnings by around USD 3.5 million/year (Pabon-Zamora
et al. 2008).
41
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112