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| Relationship between soil characteristics and preferential flow paths in forest land of granite area, the Three Gorges |
| Cheng Jinhua1, Zhang Hongjiang1, Shi Yuhu 2 |
| 1.College of Soil and Water Conservation, Beijing Forestry University, Beijing, 100083; 2.Forestry Academy of Hubei Province, 430075, Wuhan: China |
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Abstract Preferential flow paths” means the soil pores formed by plant roots, burrowing animals, cracks and fissures caused by soil shrinkage and soil swell and finger channels made by unsteady wet front. The distribution of "preferential flow paths" in soil profile was measured through the field experiments of a soil profile. Soil water characteristics were also measured by standard laboratory measurements of soil samples. The results showed that soil bulk density at depths 83cm to 110cm was the lowest. The volume of capillary pores is less than that in other layers. This shows that there are many “preferential flow paths” caused by non-capillary pores in this layer. The results also show that “preferential flow paths” are higher in the soil layer from 80*!cm to 100*!cm. The soil in this layer contains many coarse particles, which is benefit to form “preferential flow paths”. The “preferential flow paths” accelerates the saturated infiltration rate of this soil layer, and the quickly moving water in this layer also enhances further formation and development of “preferential flow paths”. The existence of “preferential flow paths” affects soil water characteristics; and on the other hand, soil water characteristics influence the formation and development of “preferential flow paths”.
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Received: 20 April 2004
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