Z0NE1 ZONE 2 ZONE 1 ZONE 2 



AMJJASO J FMAMJ J ASON J FMAMJ J A SO 



MONTH MONTH 



Figure 7.— The monthly erodent or rainfall Figure 8.— The monthly erosivity values as a 



erosivity values as a percentage of R for percentage of R for zones 1,2, 3, and 4 for 



zones 1, 2, and 3 of Straight Canyon barom- the Great Basin Experimental Area, Utah, 

 eter watershed, Utah. 



Table 5.— R values by precipitation zone for Davis County experimental watershed 

 and Great Basin experimental area 



Zone 



Vegetation 



R R-io/^2 'io/'2 



Mean elevation 









Feet 







Davis County experimental watershed 





1 



Oak brush 



15.5 5.7 1.87 



4,350 



2 



Aspen-fir 



19.4 4.2 1.94 



6,930 



3 



Spruce-fir 



14.5 4.6 2.30 



8,380 



4 



Spruce-fir 



9.6 5.4 2.49 



8,760 







Great Basin experimental area 





1 



Pinyon-juniper 



24.8 9.0 2.35 



5,550 



2 



Oak brush 



11.1 3.9 3.16 



7,650 



3 



Aspen-fir 



20.0 5.2 1.73 



8,850 



4 



Spruce-fir 



16.6 3.4 2.25 



9,850 



7 



