Applying Water Vulnerability Indexes for River Segments

The purpose of this paper is to provide an analysis and application of the indexes of water-use conflict in water resources management (i_cm) and planning (i_cp) for the Grande river basin, aiming at identifying potential water-use conflicts and thus providing a basis for the water resources management organization of Bahia state, Brazil. In order to apply the indexes, the minimum reference outflow (Q₉₀) and the long-term average streamflow (Q_lt) were estimated. Water demand was obtained from the water grant database from the Institute of the Environment and Water Resources of the State of Bahia. The results showed that in six stream segments of the basin, the legal water-use grant limit was exceeded. Some advantages of using these indexes are the possibility of assessing water scarcity at a river segment level and the fact that they provide a spatial analysis of potential conflicts in a basin. The analysis of water availability at the drainage segment level allows the management organization to act locally for the mitigation of water-use conflicts or to plan solutions for imminent conflicts.