Assessing Meteorological Drought on Islands and Island Nations: The Case for Climate Observations in Territorial Islands of the United States

When the weekly U.S. Drought Monitor (USDM) was developed in the late 1990s, the U.S. Virgin Islands (USVI) and U.S.-Affiliated Pacific Islands (USAPI) were not included due to concerns regarding the quality, quantity, and timeliness in reporting of those regions’ weather data. Typically, only post-event drought assessments were possible, using a limited number of analytical tools such as the Standardized Precipitation Index (SPI) and the Keetch-Byram Drought Index (KBDI). However, in the wake of an historic El Niño –fueled drought afflicting the Caribbean Basin in the mid-2010s, scientists at the U.S. Department of Agriculture, the U.S. Department of Commerce, the University of Nebraska-Lincoln’s National Drought Mitigation Center, and other federal and academic groups, have re-visited the potential for expanding USDM coverage to include the USVI and the USAPI. That event was compounded by the inability of the USDA to adequately assess the impacts of the drought on the local agricultural community in a timely manner underscoring the need for the Governor and other local officials to petition the Secretary of Agriculture for disaster relief.

The vulnerability of island communities to drought and other weather and climate phenomena have been magnified by the impacts of climate change, in particular rising sea level and subsequent salt water intrusion into fresh water supplies. This has an inordinate impact on coastal population centers, which in the case of the USVI, support the majority of agriculture and general economic activity. While downscaled climatic projections of rainfall and temperature trends for the U.S. Caribbean depict increasingly greater rainfall variability with more frequent drought events, the ability of the region to adapt is constrained by a low level of adaptive capacity, mainly in the form of limited economic capacity. The addition of the USVI and the USAPI to the USDM will lead to a faster federal response to those communities impacted by drought, both in terms of direct payouts to livestock producers and in drought disaster declarations, helping to ease economic impacts of drought on those communities. Federal partners, in particular the National Integrated Drought Information System, have offered significant support to the USDM team of authors and technicians to achieve an operational product with the hopes of reaching the goal of a more rapid federal response. The effort has also gained national attention as a deliverable in direct support of the National Drought Resilience Partnership, which offers policy support to activities designed to make all states and territories less vulnerable to the impact of drought.