Africa RiskView: Methodology

The Africa RiskView models and software products  are offered to countries working with the ARC Agency. Its models have been designed to be adapted and customised to work within national frameworks, strengthening existing systems and allowing governments and their partners to carry out their own risk analyses, as well as define their own risk management strategy and risk pool participation.

Rainfall

Africa RiskView uses several rainfall estimates (RFE) datasets, such as RFE 2.0 and African Rainfall Climatology v2 (ARC2) – both products of the Climate Prediction Centre (CPC) at the United States National Oceanic and Atmospheric Administration (NOAA) – but also others that continue to be added to as new dataset emerge. With these datasets, users can view actual rainfall estimates, calculate cumulative rainfall and analyse rainfall at several spatial scales. Historical rainfall datasets are available starting from the year 1983 to the present.

Drought

Africa RiskView uses the Water Requirements Satisfaction Index (WRSI) – an operational crop model originally developed by the United Nations Food and Agriculture Organization (FAO) and used widely throughout Africa and by many early warning institutions – as a meaningful indicator of how a shortage of rainfall may impact crop yields and the availability of pasture. The WRSI monitors water deficits throughout the growing season, and captures the impact of timing, amount and distribution of rainfall on staple annual rain-fed crops. In this way, Africa RiskView translates satellite-based rainfall information into a spatial drought index.

Africa RiskView then overlays this drought index on population vulnerability information to estimate drought-affected populations and response costs to assist them for past and current rainfall seasons. Vulnerable populations in ARC are determined by two factors — resiliency, which is indicated by a household’s distance from the national poverty line and exposure, which is the percentage of a household income that comes from agricultural activities (e.g. production, casual labor and livestock) that could be at-risk to drought. Household survey data reflecting these two dimensions are used to create a drought vulnerability profile of populations living in each administrative unit of a country. As countries customise the tool at the national level, the population vulnerability profiles are refined with the most up-to-date information as relevant national surveys and assessments become available.

In a final step populations affected are converted into responses costs based on a country’s response modalities and related budgeted contingency plans for ARC participation. These national modelled drought response costs are the underlying basis for ARC’s flagship parametric drought insurance products.

Every year since 2014 ARC has launched an insurance pool offering drought protection for its Member States for seasons starting in May and the year ahead based on Africa RiskView. It has been reviewed and customized by over ten countries to date and triggered four drought insurance payouts within the first two insurance pools.

Flood

In addition to drought, flood risk has also been identified as a high priority for many African countries. Developing flood insurance to help them respond more effectively to the needs of affected populations in the aftermath of a flood is a key ARC priority. The ARC River Flood Model (AFM-R) and ARC’s index-based river flood insurance product currently in development will be first of its kind in the world. With high resolution continent-wide flood extent depiction, the AFM-R model provides daily information on flood extent across Africa, with a focus on large-scale river flooding.  Based on microwave data that can detect standing water in flooded areas, AFM-R has consistent historical data going back to 1992, is produced in near real-time and, when complete, will produce estimates of river flooding impact on countries and their vulnerable populations to underpin ARC’s parametric flood insurance product offering. The model, which will be integrated into Africa RiskView, is currently being tested and ground-truthed with ARC Member States.

Tropical Cyclone

Among ARC Member States, the island states of Madagascar, Mauritius and the Comoros are the most exposed to tropical cyclones, with the coastal areas of Mozambique also at risk. ARC’s Tropical Cyclone model covers the hazards of wind, storm surge and wave damage and converts these hazard maps into USD damage estimates per storm and per country in the South West Indian Ocean.  Based on 70 years of historical cyclone records and a simulated track set for 1,500 years containing almost 10,000 cyclones, the model generates modelled loss calculations for these events – and for events that are being forecast as they develop – creating important information for early warning, disaster preparedness and planning purposes as well as for underpinning ARC’s parametric tropical cyclone insurance products. Already running and being used to track the 2016/17 tropical cyclone season in a stand-alone software tool, the tropical cyclone model will be fully integrated into Africa RiskView suite of products. Unlike in other regions where these models are deployed, the software allows users to customise some settings so that the model better fits their historic loss profiles.