Abstract
The objective of our research was to investigate geomorphologic characteristics, statistical laws of stream areas for rill networks in sloping fields, and the capability of two models for predicting drainage densities of the rill networks. Using field data on study rill networks developed in agricultural fields, we examined the average exterior and the average interior link areas, drainage densities, etc. for the rill networks. We also investigated the validity of the laws of stream areas and the capability of the drainage density models for the rill networks by the field data and a theory of channel networks. The results validated the statistical law of stream areas and Horton's law of stream areas for most of the rill networks. Moreover the results indicated that one of the drainage density models was effective for most of the rill networks and another model was capable of predicting drainage densities with reasonable accuracy for the rill networks with more than 46 sources.
