Vulnerability of arid and semi-arid regions to climate change: impacts and adaptive strategies

This perspective document, part of the 16-paper series on water and climate change adaptation, focuses on the impacts and adaptive strategies in arid and semi-arid regions. The series reflect the central topic of the 5th World Water Forum, ‘climate change and adaptation’, where it was presented and discussed. The following risks posed by climate change to the water sector in arid regions are identified.

• New technologies have led to unsustainable extraction of ground water, leading to increased vulnerability to expected falls in precipitation.
• Consumption is set to rise as countries develop and populations grow.
• Food security is threatened as agriculture requires more water in line with temperature rise.
• Increased urbanisation will strain resources and increase vulnerability to flooding, energy-failure and heat-waves.
• Ecosystems, particularly forests and wetlands, face increased risk of fire and exploding pest numbers.
• Coastal areas, especially deltas and cities, are at risk of sea-level rise.
• Disease patterns are likely to change, making control more difficult.
• Implications of climate change will likely be gendered, with women and girls suffering disproportionately.
• Scarcity of resources and increased extreme weather (flooding/droughts) are likely to create and exasperate existing conflicts between communities.
• Water quality will be reduced due to pesticides, sediments and thermal pollution. 

Difficulties facing policy decisions are covered, such as the need for strong institutional capacities to implement adaptive strategies and the difficulties of allocating funding for projects that tackle such unpredictable risks. It is urged that more funding be found for research and data collection so that this issue is mitigated. The paper then provides examples of adaptive strategies that are being planned or implemented around the world. From water allocation in the Nile Delta to glacial retreat in Ecuador, from irrigation management in Pakistan to information management in Spain, numerous examples are presented where government and communities are utilising modern technology to collect data and inform policy. Successful systems are found to contain the essential elements of assessment, bargaining, codification, delegation, engineering and feedback; these are explained in further depth. The paper includes following conclusions.

• Arid and semi-arid areas must implement adaptive strategies regarding water.
• Systemic collection and sharing of data is essential and governments must be made aware of its value.
• Training should be provided to enhance institutional capacity of water managers in developing countries.
• Irrigation infrastructure must be protected and improved.