Semi-arid Northeast Brazil: Integrated Modelling of Regional Development and Global Change Impacts

Societies in semi-arid areas in developing regions are amongst those most vulnerable to climate variability and potentially most vulnerable to climate change. The vulnerability to climate variability emerges from a combination of the level of availability of natural resources and the human dependency on these resources. In semi-arid regions, the limited availability of water and the low reliability of this availability pose strong restrictions on the use of natural resources. On the other hand, population often has a high density, and is strongly dependent on natural resources with little short-term options to reduce the dependency. Reasonable conditions in the wetter years support the persistence of population in the area; marginal or poor conditions in dryer years often have strong impacts as social disruption and population migration. The adverse conditions and arrears in development hamper significant improvements in the quality of life. Regional tradition and adaptation to local conditions serve as experiences to cope with droughts. This may help to survive emergency situations, but does not really reduce vulnerability, as it does not reduce development deficits (including education, access to markets and credits). These deficits inhibit local population to improve their own living conditions. In many semi-arid developing regions, such as Northeast Brazil, population in the rural hinterland relies heavily on agricultural production and thus depends directly on the natural resources land and water that are available. Present-day climate conditions already are marginally capable of fulfilling the societal demand for water; therefore climate change poses a serious potential threat. The interrelationships between climate, water