A novel methodology is introduced for the spatial indexing of groundwater drought ‘risks’ (GDRs). It combines reliability analysis and standardised water-level index (SWI), which is readily applicable to areas with sparse data on groundwater depth (GWD) measurements. In reliability analysis, GWDs are reformulated in terms of load, which accounts for external effects, e.g. withdrawals and recharge, as well as resistance, which accounts for system capacity with regard to drought intensities (mild, moderate, severe and extreme). Reliability analysis formulates a novel procedure by using loads and resistance to formulate a performance function, which can be treated by statistical techniques, and thereby derives values of GDR, defined as failure of an operational system but without considering consequences. GDRs at observation wells are spatially distributed by using an interpolation technique. The methodology allows for estimating time variability in GDR to derive an environmental/ ecological hazard indicator (EHI), which can serve in the management and planning of predicting groundwater drought. A Graphical User Interface (GDR V.1.0) is developed to serve as a decision support system and to derive GDR and EHI values.
