1331 



Figure b. — The relationship between oaZaulated dcwnslope soil splash due to raindrop 

 impact J rainfall intensity ^ slope steepness 3 soil bulk density ^ and the percent of 

 soil particles and water-stable aggregates between 61 and 2^000 microns y SAj (r'^=0. 92) . 

 The numbers at the comers of each surface indicate the amount of soil splash in 

 grams. Figure 5A shous the relationship for three values of bulk density and an SA 

 of 55.1 percent; figure 5B is similar except SA is 81.9 percent. 



Each of the independent variables associated with the models for bottom pan splash 

 and calculated total downslope splash have similar effects. There is the strong inter- 

 action between slope steepness and rainfall intensity; bulk density and the proportion 

 of sand-size material both act directly to increase the downslope component of total 

 soil splash. 



The average and maximum absolute deviations from the regression model are 66.0 g. 

 and 174.1 g. , respectively. The mean weight of downslope splash was 538.8 g. These 

 deviations are about twice as large as those for the bottom pan model (figs. 3A and 

 3B) . This indicates that by calculating the downslope splash component we have added 

 unexplained variation as compared to measured splash in the bottom pan. The addition 

 of unexplained variation is also indicated by the reduction in . Even so, the 

 relatively high associated with the calculated downslope model is evidence that 

 EQC3) gave a reasonable estimate of the true downslope component of soil splash due to 

 raindrop impact. This evidence is strengthened by the fact that the same parameters 

 that explain a large proportion of the variance associated with measured splash in the 

 bottom pan also explain a large proportion of the variance associated with calculated 

 downslope soil splash. 



9 



