Historical and future drought impacts on Pacific islands and atolls.
The Pacific island countries and territories are heterogeneous, with the Pacific region consisting of 28 countries divided into the Micronesia, Melanesia and Polynesia subregions.
These countries contain ~20,000 islands and atolls, scattered across the Pacific Ocean.
It covers 46% of the Earth's water surface and is home to ~100,000 people.
The larger Melanesian countries of Papua New Guinea, Fiji, New Caledonia, Solomon Islands and Vanuatu account for 90 per cent of the total population and 85 per cent of the total land area of the Pacific island countries.
The Pacific region also includes some of the smallest, remote, scattered and lowest elevation countries in the world.
There is heterogeneity between and within each other.
The higher islands have rivers, streams and groundwater.
In contrast, the smallest islands and atolls rely entirely on rainwater and shallow groundwater, sometimes on top of salt water, for drinking, cooking, washing and other socio-economic functions.
Therefore, the vulnerability of Pacific island countries to drought depends on geographical location and island type.
This paper includes case studies of impacts in three Pacific subregions (i.e., Micronesia, Melanesia and Polynesia), high islands (Papua New Guinea, Fiji, Vanuatu, Samoa, Tonga) and atolls (Tuvalu and Republic of the Marshall Islands).
Individual Pacific Islands treaties cover large areas of sea, often including multiple islands that are spatially dispersed.
As a result, the occurrence and intensity of drought varies within countries relative to the spatially affected regions of the above-mentioned rainfall drivers – El Niño, the South Pacific System, the Walker Circulation.
For example, the 1982 drought in Vanuatu was one year earlier in Pecoa (northern Vanuatu) than in Port Vila (central Vanuatu) and 16 months earlier than southern Vanuatu.
Overall, the Vanuatu government had to deal with 27 months of drought conditions.
Another example is Tuvalu during the La Niña phenomenon of 2011-2012, where Funafuti (Central Tuvalu) experienced a year of drought (January 2010 to January 2011) and Nurata Tower (South Tuvalu) experienced three droughts between March 2013 and <> <>.
Tuvalu communities and governments have been affected by drought for nearly <> years.
Meteorological drought information for Pacific Island Countries treaties is shown, along with detailed information on the duration, extent and timing of drought.
In Pacific island countries and elsewhere in the world, it is difficult to know when agricultural droughts will begin and end. This makes it difficult to plan drought emergency relief interventions in Fiji in 2015-2016 – without data, it is difficult to know where severe agricultural droughts occur and how many farmers are affected.
This often leads to delays in the planning and implementation of drought response in the agricultural sector.
There is a relationship between the onset and rupture of droughts and the close proximity of tropical cyclones to some south-central-western Pacific islands.
Both the delay in the onset of drought or the end of drought are associated with the presence of tropical cyclones in the south-central region. Tropical cyclones bring rainfall.
For example, the 1982-1983 drought in central and southern Vanuatu ended at the same time nearby.
The 1998 drought in northern and central Vanuatu ended in 1998 and 2015, and around the same time, landed on the northern islands of Vanuatu, near central and southern Vanuatu
。 According to the data, Fiji's worst meteorological drought began in a neutral phase and later continued at the beginning of the 2016-2016 El Niño.
The drought ended in January 2015 and 2016 when TC Winston landed in Fiji, and TC Winston's influence made it very difficult to recover from drought conditions.
The same drought behavior was observed in Vanuatu during the May to 1998 El Niño event.
Drought conditions began in the previous month of 1998 and lasted about a month afterward, both delaying the effectiveness of the recovery response.
Following the landfall of two tropical cyclones in <>, a tropical cyclone in Samoa was followed by drought.
Tonga also experienced drought afterwards.
This highlights one of the limitations of using the Meteorological Drought Index as a proxy indicator of agricultural drought, as rainfall associated with tropical cyclones may cause the Meteorological Drought Index to indicate that the drought is over, whereas from an agricultural point of view, the drought is not over.
bibliography
[1] Logistics Capacity Assessment: Independent State of Samoa, Technical Report
[2] Remote sensing of drought: progress, challenges and opportunities. Apocalypse Geophysics
[3] Food Security Framework for the Pacific Islands: Empirical Evidence from the Western Pacific Islands
