A new climate dashboard – released by the Robert S. Strauss Center and Development Gateway – enablesresearchers to more easily explore and analyze climate security risks and insecurities across Africa. The innovative online platform utilizes a model developed by the Strauss Center’s Climate Change and African Political Stability (CCAPS) –the Climate Change Vulnerability Model – that analyzes where and how climate-related events could disrupt Africa’s security and development. Development Gateway also developed an interactive dashboard drawing upon the data used in creating the climate vulnerability model, enabling CCAPS to explain each step of how the model was built.
The CCAPS Climate Dashboard includes an impressive model of vulnerability to climate change across Africa. The model uses 21 continent-wide indicators (many of which are sub-national), grouped into four “baskets” or categories: Climate-Related Hazard Exposure, Governance, Population Density, and Household Resilience. These baskets are evenly weighted to generate the final model.
First, we re-created the vulnerability model in ArcMap 10.1 using Model Builder and the Map Algebra tool (Figure 1 below). The top four blue circles in Figure 1 are the basket layers in raster format and the bottom four circles are the weights for each basket. These are fed into the Map Algebra Raster Calculator tool (Figure 2 below), which generates the final composite raster layer using the expression below.
Figure 1 (left). Vulnerability model in Map Builder. Figure 2 (right) Map Algebra tool.
Figure 3. Client-side and server-side work flow process to create a user-defined vulnerability map.
For example, the first map below (Figure 4) shows the vulnerability model with the CCAPS default weightings (25 Climate Hazard, 25 Population, 25 Household Resilience, 25 Governance), while the second map (Figure 5) displays the model with the revised weightings (40 Climate Hazard, 15 Population, 30 Household Resilience, and 15 Governance). As a result of these weighting changes, North Africa, Zambia and Zimbabwe are less vulnerable, most likely due to the reduced weighting of the governance variable.
Figure 4. Vulnerability map from the new CCAPS dashboard using default variable weights.
Figure 5. Vulnerability map from the new CCAPS dashboard using revised (user-adjusted) variable weights.
Try your hand at using the interactive weighting, and let us know how your models compare with ours!
Diego Dimunzio is a Senior Software Engineer, Gabriel Inchauspe is a Software Engineer, Josh Powell is the Innovation Team Manager – each work at Development Gateway