红壤坡地不同土地利用类型地表产流特征

Characteristics of Surface Runoff in Slopelands Different in Land Use in Red Soil Region

在自然降水条件下,连续8 a对红壤丘陵坡地6种不同利用方式下的地表径流进行观测分析。结果表明,自然恢复保护能显著减少地表径流量,不同土地利用类型间地表径流量存在显著差异,其大小依次为：农作区〉甜柿区〉茶园区〉湿地松区〉干扰恢复区〉恢复区。各土地利用类型地表径流量存在明显的季节分布特征,产流主要发生于4—8月,降雨量和2.5-8.0 mm·h^-1降雨强度是影响径流量的关键因素。恢复区和干扰恢复区呈现良好的水土保持效应,累积径流量增长缓慢;纯林生态系统水土保持效应与林木种类密切相关;农耕地由于土壤扰动大,水土流失严重,累积径流量增长迅速。必须通过构建合理的农林复合生态系统以进一步防治南方地区的水土流失。

A stationary observation has been carried on for 8 years （ 1998-2005）, monitoring surface runoff in the field, and exploring characteristics and variation of surface runoff with time and land use. Results show that significant differences existed in surface runoff generated by rainwater between lands different in vegetation, following an order of crop land 〉 orchard land 〉 evergreen bush land 〉 conifer forest land 〉 disturbed restoration land 〉 vegetation-restoring land. Surface runoff mainly occurred between April and August. Amount and intensity （ 2.5 - 8.0 mm · h ^-1 ） of rainfall were the key factors affecting amount of surface runoff. Vegetation-restoring land and disturbed restoration land showed nice soil-water conservation efficiency and their cumulative runoff mounted up slowly. Soil-water conservation efficiency of forest ecosystems was closely related to the type of forest, following an order of orchard land 〉 evergreen bush land 〉 conifer forest land. As a result of frequently disturbance, the crop land suffered heavy soil loss with cumulative runoff mounting up quickly. It is, therefore, advisable that proper agro-forest ecosystems be established so as to further control soil erosion in South China.