Understanding Your Risk and Impacts

 Drought Vulnerability Analysis

Vulnerability analysis provides a framework for identifying the social, economic, and environmental causes of drought impacts. It directs attention to the underlying causes of vulnerability rather than to its result, the negative impacts, which follow triggering events such as drought (Ribot et al. 1996).

For example, the direct impact of a lack of precipitation may be reduced crop yields. The underlying cause of this impact, however, may be that farmers did not use drought-resistant seeds because they did not believe them to be useful, the costs were too high, or because of some commitment to cultural beliefs.

Another example of an impact could be a farm foreclosure. This foreclosure could have many underlying causes, such as small farm size because of historical land appropriation policies, lack of credit for diversification options, farming on marginal lands, limited knowledge of possible farming options, a lack of local industry for off-farm supplemental income, or government politics (state, national, or international).

Therefore, for significant drought impacts that have been identified through a drought impact assessment, begin asking why these impacts have occurred (or why they might occur). It’s important to realize that a combination of factors might produce a given event (e.g., environmental, economic, and social factors). It might be beneficial to diagram these causal relationships in some form of a tree diagram. Two examples of a tree diagram are shown below.

Figure 1. An example of a simplified agricultural impact tree diagram. (Notice the boldface   items represent the basal causes of the listed impact. Although these items may be broken down further, this example illustrates the vulnerability assessment process.)

Figure 2. An example of a simplified urban impact tree diagram. (Notice the boldface items represent the basal causes of the listed impact [in this case, the loss of tourism revenue]. Although these items may be broken down further, this example illustrates the vulnerability assessment process.)

The tree diagrams illustrate the complexity of understanding drought impacts. The two examples provided are not meant to be comprehensive or represent an actual location. Their main purpose is to demonstrate that impacts must be examined from several perspectives to expose their true underlying causes.

Case studies and scenario building are other ways to better understand drought vulnerability. However, no matter what method is undertaken, a vulnerability assessment helps decision makers target mitigation actions that will help address the real causes of drought impacts.

Reference
Ribot, Jesse C. 1996. Introduction to Climate Variability, Climate Change, and Variability: Moving Forward by Looking Back. In: J.C. Ribot, A.R. Magalhães, and S.S. Panagides (eds.). Climate Variability, Climate Change, and Social Vulnerability in the Semi-arid Tropics. University of Cambridge, New York.