This case study summarizes the work done in the preparation of an online web-based tool (CARiDRO) that is able to facilitate and develop the assessment of drought events at regional and grid-point levels using modelled and observed datasets. It also provides a brief overview of the structure and characteristics of the application of this tool which is considered as the first step in the development of the CARIWIG cases studies related with drought.

The Caribbean Assessment Regional DROught Tool (CARiDRO) has been designed to facilitate the development of assessment of drought events at regional and grid point levels by accessing and processing several datasets available from the Regional Climate Model and a number of observed gridded datasets. The tool is able to provide results based on two Drought Indexes; the Standardized Precipitation Index and the Standardized Precipitation-Evaporation Index. The former (SPI) is a well known and popular drought index used in many regions to assess and to monitor drought events. The other one (SPEI) was designed mainly to evaluate the impact of climate change on drought and it is based on water balance instead of precipitation only.

In this case study, the evapo-transpiration values (used to compute the water balance) were calculated using the Thornwaite formulation. As both SPI and SPEI indexes are calculated at various time scales (i.e. 1-month, 2-months, 6-months, 36-months, etc) they enable the identification of different drought types such as meteorological or hydrological drought. Thus the case study sought to apply of the CARiDRO tool to help assess the potential risk of these different kinds of drought in the future.

Picture: Superqq via Flickr