WAVES

Water use modeling and development of integrated scenarios for two states in Northeastern Brazil (WAVES)

Due to the strong seasonality of precipitation and recurrent drought years, Northeastern Brazil suffers from water scarcity, which negatively influences regional development and the quality of life of the inhabitants. The goal of the interdisciplinary German-Brazilian research program WAVES  has been to support sustainability-oriented regional planning in Piauí and Ceará, two states in semi-arid Northeastern Brazil, by assessing water scarcity and agricultural production under the conditions of global change (including climate change). The assessment was achieved by deriving model-based qualitative-quantitative scenarios of the future (up to the year 2025) in the study area. These scenarios were developed by a interdisciplinary scenario group and scenario indicators were quantified by an integrated model or its individual submodels (water availability, water use, agroeconomy and migration).

We participated in the WAVES program with a subproject called "Large-scale water management modeling". We contributed by

  • developing the regional water use model NoWUM, which has been included into the integrated model developed at the Potsdam Institute for Climate Impact Research. For each of the 332 municipalities of the study region, NoWUM computes present-day and future consumptive and withdrawal water use in the irrigation, livestock, domestic, industrial and tourism sectors.
    [Download pdf Kassel World Water Series 3 (9 MB)]
  • playing a leading role in the interdisciplinary scenario group which derived the qualitative scenarios (storylines), quantified the driving forces and defined the interventions to be analyzed. The scenarios were discussed in three policy workshops with the planning authorities of Ceará.

The development of integrated qualitative-quantitative scenarios, which combine qualitative storylines with quantitative mathematical modeling, is a good method for supporting sustainability-oriented regional planning. Water use assessments (like those that have been performed in WAVES with NoWUM) are a necessary prerequisite for sustainable water resources management and planning in river basins, federal states or countries. For reasons of transparency, flexibility, ease of update and the possibility to generate scenarios of future water use, such assessments are best carried out by applying a water use model. With some modifications, NoWUM has the potential to be applied for water use assessments in other data-poor regions of the globe.

For more information, please refer to the papers of Döll and Hauschild (2002) and Döll and Krol (2003) in the list of publications.