Overland flow on a steep, forested infiltrating slope

Abstract

The generation of overland flow was measured on a steeply sloping, densely forested site having a soil of high infiltration capacity. The results indicate that the volume of overland flow generated by a given storm is mainly a function of the rainfall quantity, and is not determined by the length of slope above the point of measurement. Increased rates of overland flow are consequent upon increased rainfall intensities. Less than 0.005 of the rainfall impinging on the studied slope reached the stream as overland flow. The results are explained as a special case of the kinematic wave theory of shallow flows, where the minimum slope length acceptable by the theory is specified, and the 'depth' of overland flow includes a component for rainfall splash.