Gd. Tasker et al., REGION OF INFLUENCE REGRESSION FOR ESTIMATING THE 50-YEAR FLOOD AT UNGAGED SITES, Water resources bulletin, 32(1), 1996, pp. 163-170
Five methods of developing regional regression models to estimate floo
d characteristics at ungaged sites in Arkansas are examined. The metho
ds differ in the manner in which the State is divided into subregions.
Each successive method (A to E) is computationally more complex than
the previous method. Method A makes no subdivision. Methods B and C de
fine two and four geographic subregions, respectively. Method D uses c
luster/discriminant analysis to define subregions on the basis of simi
larities in watershed characteristics. Method E, the new region of inf
luence method, defines a unique subregion for each ungaged site. Split
-sample results indicate that, in terms of root-mean-square error meth
od E (38 percent error) is best. Methods C and D (42 and 41 percent er
ror) were in a virtual tie for second, and methods B (44 percent error
) and A (49 percent error) were fourth and fifth best.