Making maps useful for addressing disasters and climate change

hazard maps
UNDERSTANDING MAPS. This is a screenshot of the maps on landslide and flood susceptibility from the Department of Environment and Natural Resources (Mines and Geosciences Bureau). The maps are in jpeg format, and require considerable work for reuse.

‘In a time when people are increasingly exposed to the factors of disaster and climate change, I believe that usable maps can help people make a difference’

August 2, 2017 — When addressing disasters and climate change, at what point does the geographic information become useful?

This is the main question of a masters dissertation I am preparing with the support of the British Red Cross. It is part of my final requirements under the MSc Geospatial Analysis program in University College London (UCL).

Originally, the question was born out my curiosity in making better maps about the risks and vulnerabilities behind disasters and climate change.

During my experience in working as a geographer and urban planner for UN-Habitat Philippines in disaster-hit areas, I have observed that there were difficulties when using geographic information in addressing such risks and vulnerabilities.

First of all, issues in using such information can arise when using maps from multiple sources and methods.

Here is a comparison of hazard maps of the Tacloban City, which was the main settlement hit by Haiyan in 2013.

understanding maps
UNDERSTANDING MAPS. This is a screenshot of the maps on landslide and flood susceptibility from the Department of Environment and Natural Resources (Mines and Geosciences Bureau). The maps are in jpeg format, and require considerable work for reuse.

When we were showing the maps to authorities and residents, we were asked this very strong question: “so which maps should we believe?”

Disaster scenarios

These are maps of the same place, and back then during the typhoon response, both were official maps. Furthermore, let me show you a picture of related issues through these scenarios:

  1. A major disaster (like Super Typhoon Haiyan) hits a major urban area, and the mayor asks for help in planning recovery and reconstruction in the most efficient way. But soon, you discover that the format in which some of the geospatial data are available will take you months to reprocess into something useful. This is a problem of accessibility.
  2. The process of recovery and reconstruction requires a lot of consultation and decision-making, especially with citizens. But you later find out that the “risk” maps only visualise hazards (hazard are not equal to risk), and not how people are vulnerable to those hazards and the exposed assets that are important to the people. Hence, the residents complain that they don’t completely trust the map because the things that are familiar to them (such as their community assets) are not in the “risk” map. Some of the residents’ houses are not even in the map. The maps don’t give the complete picture; and may allow a misunderstanding of the dangers. This can be a problem of context, semantics, and trust.
  3. There’s another powerful typhoon coming; and the town and village leaders need maps to help them plan the evacuation of the residents. But you notice that some of the roads and houses are missing from the available data from the national government. This can be a problem of completeness and representation.
  4. While crafting a post-disaster policy, the national government decides that all places at the coastal zones are dangerous. They declare that all households within 40-meters of the coastline should move out. But when comparing the “40-meter no-build-zone” with the datasets of from different agencies (e.g. the department for environment vs. department for science), there are differences, as seen in the visual comparison above. This can be a problem of uncertainty, error, ambiguity, and vagueness.

All of these issues are related to the quality of the geographic information (or spatial data as others call it). And all of these affect the usability of the maps and other knowledge products that are based on such information.

Making maps useful

These complex issues are at the center of what I am trying to do. My claim is that institutions and communities in the Philippines can better reduce risks and vulnerabilities if such issues on the geographic information are better understood and addressed.

Having usable geographic information on the topic can benefit policy, planning, and project management in the long run. Hence, for practical reasons my current research is approaching the problem through the lens of usability.

As I wrap up in the next few weeks, I hope to do the following:

  • Understand the context and scenarios of use of geographic information for reducing risks and vulnerabilities in the Philippines; and
  • Identify issues on the usability of such information for mapping and other purposes.

In a time when people are increasingly exposed to the factors of disaster and climate change, I believe that usable maps can help people make a difference.


by David Garcia | Rappler.com

David Garcia specializes in placemaking, cartography, and spatial data science. He is currently a volunteer geographer at Missing Maps Project. Garcia is also currently enrolled under the MSc Geospatial Analysis program in University College London (UCL).