Agriculture Reference
In-Depth Information
6.2.1 Water Scarcity
Water scarcity has been widely called the top global issue of concern in devel-
oped and developing countries alike. By 2025, it is estimated that between 46 and
52 countries, with an aggregate population of about 3 billion people, will suffer
from water scarcity. Coping with water scarcity is compounded by soil degradation,
groundwater depletion, water pollution, and the high costs of developing new water
supplies or transferring water from water rich to water poor areas. Through water-
shed management, we can recognize both the opportunities and limitations of water
yield enhancement through vegetative and structural measures.
6.2.2 Floods, Landslides, and Torrents
Floods, landslides, and torrents result in billions of dollars being spent each year
globally for flood prevention, flood forecasting, and hillslope stabilization. Yet the
cost of lives and property damage due to floods, landslides, and debris flows are
staggering. The impact of these naturally occurring phenomena are exacerbated by
human encroachment on floodplains and other hazardous areas, which is often the
result of land scarcity discussed below. In many parts of the world there has been an
overreliance on structural solutions (dams, levees, channel structures, etc.) in river
basins, along floodplains, and in areas susceptible to debris torrents, all of which
impart a false sense of security to those living in hazardous areas. In addition, the
replacement of natural wetlands, riparian systems, and floodplains with urban and
agricultural systems can cumulatively add to downstream problems. A watershed
perspective brings these cumulative effects and linkages into focus, but the ability
to develop solutions requires that we have the appropriate policy and institutional
support.
6.2.3 Water Pollution
Point and nonpoint water pollution continue to plague many parts of the world,
threatening the health of humans, compounding water scarcity issues noted above,
and adversely impacting aquatic ecosystems, with subsequent implications for
fish and wildlife. Best Management Practices (BMPs) and related technologies of
watershed management have the advantage of stopping nonpoint pollution at its
source.
6.2.4 Population Pressure and Land Shrinkage
Scarcity of land and natural resources results from a shrinking arable land due to
expanding populations of humans and livestock. Land degradation resulting from
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