ABSTRACT
Water is considered a scarce resource in arid and semi-arid areas, which occupy approximately one-third of the land, yet the demand for water is growing as populations expand and economies develop. At the same time, threats to existing water resources are also increasing due to pollution, overexploitation of resources, and climate change. The importance of water to the natural environment and the need for conservation of resources to protect valuable ecosystems are increasingly recognized in arid and semi-arid areas. Water is also a major hazard. Floods remain one of the most damaging and dangerous natural hazards globally, and ood risk is increasing with increasing development, as housing, industry, and infrastructure, which are increasingly encroaching on ood-prone areas, expand. Climate change is expected to lead to intensication of extreme events and further increases in risk. This will be discussed in Chapter 2.
