Runoff Generated by Rainwater on Red Soil Sloping Land and Its Landscape Reaction of Soil Erosion

A positional observation has been carried out for 4 years (1998~2001) by way of onthespot measurement in the runoff field. The results show that there are significant differences of systematic soil erosion in the course of runoff generated by rainwater among landscapes with different vegetation. The loss of water shows the following order: crop section>evergreen bush section and conifer section>evergreen orchard section>degeneration section and restoration section. The differences of the direct runoff of rainwater among different landscapes of hillside fields provide basis and controllability for the utilization of rainwater on hillside fields and for using hillside fields to collect rainwater to support farmland irrigation. Soil erosion is greatly affected by artificial interference and farming intensity .The amount of soil erosion in hillside field system increases 20 times from natural protection to crop cultivation. Soil erosion of tea and fruit forest is 2~3 times lower than that of crop cultivation, but 6~12 times higher than that of natural use and natural protection. Nutrient loss both in quantity and quality depends on landscape constitution. It suggested that we should use the rainwater collecting superiority on hillside fields to construct agroforest ecosystems on hillside fields suitable to water cycling equilibrium in unit ecosystem and to maintain water equilibrium in ecosystems by ecological construction of water equilibrium.