The water availability deficit is a governance crisis and an environmental, social, and economic risk. This study presents a spatial multicriteria approach for mapping Water Scarcity Vulnerability (WSV) and a comparative analysis of criteria weighting techniques to support the management of water resources in semiarid regions. Initially, nine vulnerability indicators were identified from a literature review and spatialized through a Geographic Information System (GIS) for a water donor region and another recipient from the São Francisco River, in the semiarid region of Brazil. Subsequently, one subjective and two objectives weighting techniques were implemented and compared to measure the weights of the indicators. Finally, the Viekriterijumsko Kompromisno Rangiranje (VIKOR) method was combined with GIS to construct WSV maps. The results indicate the conditions of WSV in the transposition water donor region can be more critical than the region receiver, and the choice of the weighting method influences the results of the multicriteria-GIS approaches. The WSV mapping approach can be helpful for water management decision-making to identify priority areas and spatial inequalities. The comparative analysis in this study can provide a valuable reference for choosing weighting methods in spatial multicriteria applications.