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  • Bishrant Adhikari, University of Wyoming

Use of OpenStreetMap and InaSAFE for assessing wildfire risk to high-value assets

We often hear OpenStreetMap labeled as a “Wikipedia of maps” with more than three million contributors. The most common features mapped either by a beginner or by an expert are the buildings and roads around their neighborhood. Mapping of these high-value assets provides are of great importance to humanitarian organizations as it gives a clear picture of the settlements and infrastructures in a particular area. OSM data has been used to support relief distribution during and after several disasters, such as earthquakes, hurricanes, and floods. The data available in OpenStreetMap allows agencies and local groups to efficiently plan and allocate their resources for evacuation and relief distribution activities.

Wildfires have been recognized as a significant problem across the United States with more than 72,000 wildfires burning on average 6 million acres every year, since 2000. Billions of dollars are spent every year in evacuating communities and suppressing wildfire spread. During a wildfire event, the priority is to protect populations at high risk from wildfires. United States Forest Service has created a Wildland Fire Decision Support System (WFDSS) to aid firefighters in making informed decisions about the values and settlements at risk. However, the information location of individual buildings is still scarce in official GIS data. On the other hand, OSM has a relatively dense coverage regarding building footprints.

Assessment of wildfire risk was conducted in the US through two regional level projects known as the Southern Wildfire Risk Assessment (SWRA) and West-Wide Wildfire Risk Assessment Project (WWA). SWRA covered 13 southern states whereas WWA spanned 17 western states. The information about wildfire behavior was presented in the form of wildfire threat, fire intensity, and wildfire risk indices. This information could be used to determine the high-value assets that are at risk from wildfires. The wildfire risk information is usually presented through the state-wide risk assessment portals. One of such web GIS-based portal developed for the state of Wyoming is shown below:

These risk layers created by the WWA project could be used to estimate the number of buildings in different risk zones using open-source hazard assessment software such as InaSAFE. InaSAFE was developed by the Indonesian and Australian Government in collaboration with the World Bank. InaSAFE was designed to analyze “natural hazard impact scenarios” and support “planning, preparedness, and response activities.” InaSAFE provides a mechanism to integrate data from local communities, research groups, and government agencies to evaluate “impacts of future disaster events.” InaSAFE is distributed as a plugin to the most widely used Open Source GIS software, QGIS. The user-friendly interface and well-documented functionalities make InaSAFE readily usable by any user interested in hazard assessment.

A simple wildfire hazard scenario was simulated to understand the potential of InaSAFE beyond its most widely used hazards, such as Flood, Tsunami, Earthquake, Volcano, Cyclone and Dam Break. The Wildfire risk layer was created using the data produced by the West-Wide Wildfire Risk Assessment Project and provided by the Wyoming State Forestry Division. The building footprints and road network data was extracted from OpenStreetMap. InaSAFE provided an easy to use walk-through interface to prepare layers, create keywords, and set result aggregation criteria. An analysis was executed using InaSAFE and OSM data to analyze buildings at risk from wildfires. A result after the execution of InaSAFE model showing number and location of buildings in different risk zones is shown in the figure below.

InaSAFE calculated the number of structures in each risk zones along with a comprehensive report consisting of estimated resources required for relief distribution. A similar assessment can be performed for various other high-value assets such as protected areas and road networks. Moreover, the estimated population affected by this hazard can also be calculated using InaSAFE with inputs from the Gridded Population of the World. The powerful risk assessment functionality of InaSAFE could be used for assessing wildfire risk to the high-value assets. Additionally, the continuous updating of OSM data by the vibrant OSM community might make it a handy tool for the planners to make informed decisions on wildfire management and evacuation planning.

Bishrant Adhikari is a geospatial applications developer currently almost pursuing his Masters of Geography at the University of Wyoming. Bishrant, originally from Nepal, has a wide array of experiences ranging from field surveyor, GIS lecturer, GIS analyst, and GIS programmer. Bishrant is passionate about making advances in geospatial technology accessible to the citizens via web GIS portals and information systems. Bishrant loves to travel and read novels in his free time. Bishrant is currently working with Wyoming Geographic Information Science Center to develop the Wyoming Wildfire Risk Assessment Portal for the Wyoming State Forestry Division.

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