Changes of preferential flow path on different altitudinal zones in the Three Gorges Reservoir Area, China

Abstract

Liu, M., Du, W. and Zhang, H. 2014. Changes of preferential flow path on different altitudinal zones in the Three Gorges Reservoir Area, China. Can. J. Soil Sci. 94: 177-188. Preferential flow in soil macropores plays an important role in runoff control and soil and water conservation. The aim of this study was to investigate the distribution of preferential flow paths in the soil profile of various altitudinal belts, analyze its variation among different soil horizons, and define the cause of soil macropores. A dye tracer method combined with photographic analysis was conducted for four hillslope sites in the Three Gorges Reservoir Area of China (TGRA). The results show that stained area proportion, as well as its vertical distribution in soil sections, presented varied patterns due to changes of forest vegetation and soil type with altitude. Stained area ratio of soil profiles increased, while stained depth decreased with increasing altitude. For soil sections in the subalpine belt, mid-mountain belt, a...