Influence of Initial Infiltration on Runoff Hydrographs from a Test Field in a Semiarid Region of Northeastern Brazil

Abstract

Predicting runoff using a kinematic model has become a useful tool, but to model this process special care must be taken when the infiltration for a given event is estimated. In this paper, hydrographs due to runoff with different initial infiltration capacity of soil and various types of rainfall are discussed for a Brazilian semiarid area using data obtained from a test field in the area. In the discussion, the Green and Ampt infiltration equation during a steady rain is used and the moisture-tension parameter is studied separately. Thus a new method for estimating this parameter for a Brazilian semiarid area is proposed.