NW US Wildland Threats

Assessing Multiple Threats at Regional and National Scales

The layers presented in this map were built with a tool that combines data describing potential wildfire, insects, and disease, and urban development to identify locations that may be exposed to multiple forest threats. The data and maps are based on a novel 15-mile radius neighborhood analysis that highlights locations where forest threats are more concentrated relative to other areas, and identifies where multiple threats may intersect. Policymakers and managers often rely on maps showing where forest threats are most prevalent, to assess threats in relation to the forest resources most valued by the public. Management priorities are then made based on this information. The methods, data, and maps available here provide a way to combine and display forest threat data at its appropriate spatial scale and in a way that transcends political boundaries, using readily available GIS [geographic information system] analytical tools. The approach recognizes that a single point mapped as potentially highly vulnerable to a threat may not be all that important from a regional or national planning perspective. What is important is the concentration of threats within a defined and appropriate spatial scale of interest.

The methods are based on research that began in 2008 and examined spatial data characterizing wildfire, insects and disease, and urban and exurban development in the northwestern United States. It covered 488 thousand square miles in the states of Idaho, Montana, Oregon, Washington, and Wyoming, using a novel 15-mile radius neighborhood analysis to highlight locations where a given disturbance threat may be more concentrated relative to other areas. The maps and overlays can help managers locate regions where potential threat combinations are most prevalent. Such assessments can help managers allocate resources toward mitigation efforts and better use shrinking budgets. Federal wildfire suppression expenditures exceeded $1 billion in 2000. They have exceeded that amount nearly every year since, according to the National Interagency Fire Center. Although the original study focused on the five-state northwestern US region, ongoing research during the fall of 2013 will extend the research to the entire US, as well as include potential climate change effects.

This mapping application is part of a family of Wildland Threat Mapping (WTM) applications developed by WWETAC to portray the spatial interactions of wildland threats and high value resources that occur in wildlands. Visit WWETAC's WTM page for a collection of these mapping applications.

PNW_jpgWTM NW Wildland Threats

The link above loads an interactive 2D map in your internet web browser - no software installation is required. To navigate around the map, Left-click and drag your mouse to pan, use your mouse wheel or the slider control in the upper left to zoom, and Shift-Left click to drag to define a new map extent. Click on the 'Tools' pane on the right side to access tools such as zoom to layer, zoom to a user-defined point, and identify.


Kline, J.D., B.K. Kerns, M. Day, and R.B. Hammer. 2013. Mapping multiple forest threats in the northwestern US. Journal of Forestry 111(3):206-213). Click here for a PDF of the paper.