APPLICATION OF THE UVE FUEL MOISTURE MODEL 



To apply the live fuel model, the following conditions must be met: 



(1) Weather observations must be started 3 to 4 weeks prior to the onset of 

 greenup. This assures that the 1000-h TL fuel moisture has stabilized 

 at a reasonable value for current weather conditions. 



(2) Greenup must be defined at the proper time 



(3) Herbaceous plants must be correctly designated as annuals or perennials. 



(4) Climate class must be selected. The climate class should be selected 

 for the location of the weather station. The choice of climate classes 

 compensates for a lack of local live fuel moisture data. 



The user has the capability to "tune" the live fuel model to produce live woody and 

 herbaceous moisture profiles that are reasonable for his area. This can be done by 

 designating herbaceous plants as annuals or perennials, and selecting the proper 

 climate class. 



Setect-lon of Annual or Perennial Designation for Herbs and Forbs - Although the 

 moisture content of annuals does not increase after greenup is complete, the live fuel 

 model does assign the same drying rate to both annuals and perennials at moisture con- 

 tents above 120 percent. During transition (HFM between 120 percent and 30 percent); 

 however, annuals dry at a much faster rate than perennials. Thus, the live fuel model 

 typically indicates a curing of annuals sometime during the summer season, but peren- 

 nials do not cure until a freeze occurs. The annual designation should be used only 

 if more than half of the herbaceous plants are annuals. 



Selection of Climate Class - The user can affect live fuel moisture estimations 

 through his selection of climate class. The effect of climate class selection on the 

 moisture profile for perennial herbaceous grass is shown in figure 9. Climate class 3 

 is the proper selection for this data set. Normally, it is useful to test only one 

 climate class above or below the one that is estimated to be appropriate for a partic- 

 ular fire weather station. 



These controls provide the user with a great deal of flexibility to "tune" the 

 live fuel model until it provides realistic moisture profiles for his area. 



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