Drought Monitoring

Visit our Sri Lanka Drought portal for more details.

Drought is the disaster that affects most Sri Lankans. Drought may be characterized in terms of its rainfall deficits and excess evaporation (meteorological), shortfalls in streamflow and soil moisture (hydrological), impacts on agriculture (agricultural) or impacts on people and ecosystems. We find that relief payments relate strongly to rainfall deficits as measured by drought indices (Lyon et al., 2011).

Figure 1: SPI Map for the 2019 (Apr-Jun) and Three Monthly SPI Time Series for the 4 Climate Regions from May 2001 to June 2019

The drought index known as Standardized Precipitation Index (SPI) calculated over the last 3 months is shown for the region around Sri Lanka is mapped below. The Northern Jaffna, Vavuniya and Mannar districts and the Kandy, Nuwara Eliya and the boundary between Ratnapura and Moneragala districts show the strongest drought.

The history of the drought index for the last 19 years is also shown. The intensity of the drought is shown as bars and darker the brown the greater the strength of the drought. During the current period there is a significant drought in Northern and Eastern region. However, the drought is not as severe as in 2004 or 2014

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Rainfall Monitoring

The 3 Panels below shows the variation by dekadal (3 times a month) and the map shows anomalies for the first half of the Maha Season 2018/19 starting from the month of September

Comparison of current rainfall past 6 Years — Figure 3: Comparison of current rainfall during past 6 years

Dekadal 10-Day rainfall — Figure 4 : Dekadal (10-Day) rainfall during first half of the Maha season 2018/19 compared to the past average. The blue bars show above-average rainfall anomalies and brown bars shows below average rainfall anomalies.