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Drought is a complex natural phenomenon that lacks a universally accepted definition, thus it is difficult to confront holistically. Several efforts have been made towards managing the widespread and catastrophic drought impacts. In this quest, the concept of vulnerability to drought seems to offer some significant potential. In the present attempt, a standardized drought vulnerability index (SDVI) is presented, applied, and spatially visualized through geostatistical methods on a country scale. Greece, experiencing frequent and intense droughts, was selected as the study site. In an effort to link drought characteristics to impacts, the index incorporates water supply information, demand data, the state of the relevant water infrastructure and climatic parameters represented by the standardized precipitation index. The index showed potential in portraying various vulnerability states and followed satisfactorily the vulnerability fluctuations in Greece in relation to recorded drought hazard dimensions and impacts. The SDVI may be considered as a first step for the emergence of an integrated SDVI with multiscalar applications in environmental research and decision-making. It is believed that improving techniques in index formulation may complement more reasonable and acceptable solutions to water challenges posed by droughts and help avoid a drifting sense of continuous 'water crises'.

A B S T R A C TThe mesoscale numerical weather prediction model ALADIN has been applied for downscaling ERA40 data onto a 10 km grid covering the complex terrain of Slovenia. The modelled wind field is compared with the time-series of observations at 11 stations. In addition to traditional scores (root-mean-square error, mean absolute error, anomaly correlation), a frequency-domain comparison is carried out in order to explore aspects of the mesoscale model performance other than that depicted by the conventional statistics. The verification period is the Special Observing Period of the Mesoscale Alpine Program (MAP-SOP), for which ECMWF reanalyses including MAP-SOP observations are available every 3 hr on a ∼40 km grid.Traditional scores indicate that the downscaling has been successful. Scores are little dependent on the nesting strategy (direct versus two-step nesting), in spite of a ratio of horizontal resolutions between ERA40 and ALADIN as large as 12. The model performs best at mountaintop stations, characterized by over 80% of their spectral power in motions with longer than diurnal periods. A majority of stations is, however, located in the complex terrain where around 40% of the spectral wind power is contained in the subdiurnal frequency range. This part of the spectrum is significantly underestimated by the model, indicating that the downscaling is predominantly a dynamical adjustment to the new terrain. At the same time, the MAP-SOP reanalyses of the ECMWF model include relatively more power in the subdiurnal frequency range than ALADIN. However, these subdiurnal oscillations do not agree with observations and their removal improves conventional scores for the MAP-SOP wind data.It is suggested that a frequency-domain comparison is a useful complement to the conventional statistics and it enables a more physical insight into a mesoscale model performance.

Full affiliations in Supplement 1 at www. int-res. com/ articles/ suppl/ c075 p241 _ supp. pdf ABSTRACT: Addressing timely and relevant questions across a multitude of spatio-temporal scales, state-of-the-art interdisciplinary drought research will likely increase in importance under projected climate change. Given the complexity of the various direct and indirect causes and consequences of a drier world, scientific tasks need to be coordinated efficiently. Drought-related research endeavors ranging from individual projects to global initiatives therefore require prioritization. Here, we present 60 priority questions for optimizing future drought research. This topical catalogue reflects the experience of 65 scholars from 21 countries and almost 20 fields of research in both natural sciences and the humanities. The set of drought-related questions primarily covers drought monitoring, impacts, forecasting, climatology, adaptation, as well as planning and policy. The questions highlight the increasingly important role of remote sensing techniques in drought monitoring, importance of drought forecasting and understanding the relationships between drought parameters and drought impacts, but also challenges of drought adaptation and preparedness policies.

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