Issue: create topographic and meteorological databases with GIS, display
the results of a diagnostic wind model, and
perform analyses on the combined effects of slope and estimated surface
wind filed with a slope-wind interaction model

Study area: San Jacinto Mountain, S. California

Diagnostic wind field model: KRISSY (dev in mid 80s)
        using 3-D topography,
        vertical profile of horizontal wind speed and direction,
        synoptic-scale pressure gradient, and
        inverse squared distance interpolation,
        the model estimates wind direction and speed for surface
        grids and above surface grids

Model constraints:
        concordance with surface and upper air observations
        mass consistency

Data:
        surface: wind speed, direction, temperature at 21 locations,
                        1:24,000 DEM
        upper air: 1 vertical profile of wind and temperature

GIS processes: (Arc/Info)
        resample DEM to 150m cells
        attatch locations for elevation and weather data for KRISSY
        convert model output in GIS: elevation, wind direction,
        speed, E-W, N-S, and vertical component of wind
        prepare slope angle and aspect for the following modeling

Slope-Wind interaction model:
        fire spread rates increase upslopes and with slope aspect
        SWIFi,j=Vi,j * (1 + ((sinSi,j)^0.5 * (cos(qi,j - di,j))))
        S - slope angle, qi,j - wind direction, di,j - slope aspect,
        V - wind speed, ranges 0 ~ 2V₀, as S ranges 90⁰ ~ -90⁰

GIS process:
        display fire potential using a set of graduated point symbols

Possible error sources:
        resampled terrain data
        surface wind observation
        spatial distribution of the wind observation

Improvement
        improve weather data
 
 
 

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