Needs severity mapping

Prioritize WASH needs through a WASH severity mapping

When facing a disaster, people have different severity of needs. Some communities and/or population groups are more affected than others, some are more resilient than others. Humanitarian response cannot reach all people in need of assistance: areas with the most severe needs should be identified and prioritized. This process is called needs severity mapping. Coordination platforms first undertake sectoral severity mapping, later consolidated by OCHA at the intersectoral level. There is no standard methodology to prioritize sectorial needs; two common approaches are however presented below:

  • Use a severity scale based on several WASH indicators (ex: access to improve water sources) and non-WASH indicators (ex. prevalence of malnutrition, etc.). Create a composite index and rank each administrative level from 1 to 5 (or 7), from “No problem” to “Catastrophic problem”. Indicators can be weighted, if some are considered more important than others, depending on the context.
  • Classify administrative level from the lowest to highest WASH PIN number, or by the percentage of PIN as compared to the whole population. Identify thresholds and rank each administrative level from 1 to 5 (or 7), from “No problem” to “Catastrophic problem” based on PIN figures, or the percentage of PIN as compared to the whole population.

When there is a large geographical area to be mapped with many administrative levels, it quickly becomes impossible to cross several indicators with a qualitative approach. In this case, analytical tools to integrate multiple indicators must be used. Two examples are presented below:

  • INFORM software (http://www.inform-index.org/About-us)
  • 1000Minds software: a simple and transparent method to identify vulnerable populations. Without the need to shape available data to fit pre-defined weights, the software undertakes a multi-criteria analysis on the data that is available at the time of the emergency. 1000minds software has been identified as a valuable tool to identify vulnerable populations in an easy, flexible and transparent way. In the Key Guidance and Tools section above this page can be found the 2016 GWC 1000Minds Prioritisation Tool, which contains a WASH-specific step-by-step manual to use 1000Minds to calculate the needs/priorities of the affected population, as well as example datasets and results from Somalia.

A severity map can finally be designed, and used to show severity of needs per geographic location. Regardless of the approach taken, the exercise should be documented to ensure full replicability of the process.

Refer to the 2015 OCHA Humanitarian Needs Comparison Tool presentation and tool box for more details on integrated severity mapping.


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