Forest fires, water stress, and watershed condition in the western US

• Are intense fires or fires of large extent (stand-replacing fires) set up by excess forest growth, enabled by histories of vigilant fire suppression? 
• Does high forest density result in high water use (evapotranspiration, ET) by trees, thus, in reduced surface water flows for human use and river organisms?  
• Is mechanical forest thinning to remedy the apparent problems far too expensive? 
• Does the discipline of fire ecology offer increasingly better solutions? 
• How can we assess forest condition cost-effectively on the ground or by remote sensing?

   More detailed analysis and plans for both research and action can be found on another page here.

·        Major effort already designed: remote sensing of evapotranspiration rates at good resolution over large areas and over time…and carried all the way to assessment of deviations from sustainable stand density, consequent estimation of fire probabilities, surface water yield

o       Using versions of the surface energy balance method on satellite imagery

o       Improving the method with extensive automation

o       Improving the method with better process-based equations

o       Importantly, developing the interpretation of the time series of ET versus a concept of equilibrium ET.  This is a major extension of the concepts of equilibrium leaf area index (stand development) and of long-term partitioning of energy and water fluxes

·        A proposal was made to NASA hydrology; not funded; less than desired high emphasis on remote sensing (instead, much on ground validation and interpretation)

   Potential clients:

• Water managers (USGS, Bureau of Reclamation, state engineers, state water resources boards, municipal water managers, irrigation districts)
• We have latent contacts with many of these people, from prior projects - the managers and agencies need to see closer ties of legal and regulatory mandates with these specific issues, and they also need some additional and less-restrictive funding to apply to efforts such as we propose (funding seems promising currently)
• Foresters (federal, state)
• Ditto, on contacts

   Complementary or competing selling points:

• Competing: ET monitoring by satellites: already commercialized in US by Rick Allen, U. Idaho.  Not automated; costly ($5K per ASTER scene for his group to process it); statistics on accuracy seem selective (e.g., time series at single sites, not comparing sites with very different aerodynamic resistance and varied soil wetness) or otherwise problematic to us, esp. over forests, where temperature differences that are critical to resolve ET are very small; process equations have serious deficiencies, which a Ph. D. student advised by the consortium director has remedied, with remarkable results (alas, her methods are going to be a major challenge to automate)
• Competing: Forest stress and density assessment, and tests of on-the-ground treatments for excess stand density: Wally Covington, Northern Az. U., has an Ecological Restoration Institute supported by the US Forest Service.  He has already judged various areas to be overly dense and is testing various thinning methods and degrees.  He has a long-established program with relatively little opportunity for our collaboration.  He uses some remote sensing, but only for land cover classification and leaf area, not for ET.
• Complementary: Forest fire probability monitoring and modelling, using current methods: There are both ground-based surveys of fuel load (a lot of walking, spotty coverage) and remote sensing estimates of forest water stress, supplemented by weather data (weak signal, only moderate reliability).  No one to date uses ET measurements to estimate water stress levels.  Caveat even for our method: water stress in the leaves is not fully synchronous with drying of fuel load below the tree canopy, and it’s the latter that matters most.
• Complementary: Forest fire monitoring: there are excellent near-real-time systems for tracking fires that have already originated.  The MODIS products team at U. Md. is a key player.  We might collaborate on using fire data gathered by Chris and his colleagues (and other historic data, as also from Bill Romme, Colorado State U., and others) to test the ideas of equilibrium stand density and equilibrium ET (e.g., do deviations from these indicate high fire probability, esp. high probability of an abnormal fire type?)           
• Complementary:  Modelling of forest fire spread, once initiated - useful for preventive pretreatment of forest, alerts, and aiding the deployment of firefighters: We do not currently track the current development of the models, but types of developments give us some perspective:
• Craig Loehle, an ecologist with the National Council for Air and Stream Improvement, has applied percolation theory to show that reduction in fire hazard on as little as 10-25% of the forest can severely restrict the spread of forest fires.  To date, forest managers have shown little interest.  If we can kindle interest in his findings, we could put in our identification of "hot spots" to treat.
• Rod Lynn and colleagues at Los Alamos Labs have a fire spread model.  It appears to be too data-hungry to use at the moment.  With judicious simplification, it could be coupled with our remote sensing, too.
• Complementary: Forest hydrology and water yield to surface supplies: very many people - hydrologists, foresters, and others - use combinations of models and field measurements to track water yield and , to varying degrees, relate it to forest stand conditions.  The only group that estimates ET as a major process competing with runoff to surface waters is, again, Rick Allen. Some water managers use his products.  Many more would use his or our products if they were:
• Less expensive
• Easier to use
• Quick to tie into surface models and measurements