A viable drought vulnerability index for outermost small islands in Indonesia

The rate and duration of precipitation in many outermost small islands within the Indonesian region have been projected to decrease during the dry season due to prolonged droughts. Thus, drought mitigation plans for these islands must be adaptive and continually improved. As a result of recent advances, drought periods can be monitored and relevant information communicated using water requirement assessment embedded within a geographical information system (GIS)-based model. Although improved tools and models have been used to analyse data concerning water conditions, only a few studies have focused on drought in the outermost small islands in Indonesia. The main purpose of this study was to inform regulatory agencies on the drought status of these small islands. Thus, the viable drought vulnerability index (DVI) was developed to contribute to the construction of a support system to make relevant decisions about the drought status of the islands. Specific parameters were selected to develop and analyse DVI, involving three considerations: meteorological, physical, and socio-economic aspects. This study focused on the analysis of data from water resources availability (rainfall, surface water, and groundwater), population, and interpretations from GIS to establish the rainfall index (RI), water use index (WUI), water supplying vegetation index (WSVI), and critical-land rate index (CRI) to develop a viable DVI. The results provide a clear understanding for all stakeholders concerning the drought problem and use a viable index and vulnerable map as valuable tools for water management in the study area. The results also confirm that a GIS approach is effective in identifying and measuring the vulnerability index in the outermost small island area, aiding in the implementation of better adaptive drought management practices for sustainable development.