黄土丘陵区土壤抗水蚀能力变化的动态评估  

Dynamic Assessment of Soil Anti-Erodibility by Water in Small Watershed of Loess Hilly-gully Region

作　　者：尹乐[1] 倪晋仁[1] 

机构地区：[1]北京大学环境工程系,水沙科学教育部重点实验室,北京100871

出　　处：《自然资源学报》2007年第5期724-734,共11页Journal of Natural Resources

基　　金：国家自然科学基金项目(50579001);国家重点基础研究发展计划项目(2007CB407202)。

摘　　要：以黄土丘陵区典型小流域纸坊沟为研究对象,建立了土壤抗水蚀能力动态评价的指标体系,利用层次分析法对1938～2000年间研究区域的土壤抗水蚀能力进行了动态评估。引入土壤相对抗水蚀能力指标,并采用生态系统健康和承载力相关概念,研究了流域土壤抗水蚀能力偏离理想状态程度的变化情况,分析了其健康状态变化、恢复力和可恢复程度;通过与土地利用结构状态变化过程与恢复特性的比较,揭示了土壤抗水蚀能力对于土地利用结构变化的响应关系,指出了响应曲线中的滞后特点并对其产生的原因进行了分析。研究结果与前人所得的结果吻合较好,说明研究中采用的方法能够有效预测土壤抗水蚀能力,也可为水土保持恢复和管理工作提供科学支持。An indicator system was proposed for dynamic assessment of soil anti-erodibility by water （SAEW）.A typical small watershed,Zhifanggou in Loess Hilly-gully region,was selected as a study area where dynamic change process of the SAEW was assessed in the period of 1938 to 2000. Relative SAEW index （RSAEW1） together with the concepts of ecosystem health and carrying ability were introduced to evaluate the variation degree of the SAEW, taking the SAEW in 1938 as a benchmark representing the natural conditions.Moreover, the change of the ecosystem health states and resilience characteristics was analyzed.The results showed the SAEW of Zhifanggou Watershed was in the natural state in 1938,since then,because of the human actives＇ interferences, the SAEW became lower with high velocity.The trend changed in 1961,when the SAEW reached its lowest level.The SAEW began to recover around 1963,but the recovery speed was relatively slow,and the SAEW failed to meet its natural level after 39 years＇ recovery.The SAEW was an important aspect of ecosystem,with the conception of ecosystem health and carrying ability,the SAEW index was graded according to the different health states of ecosystem.In the aspect of SAEW, the ecosystem of Zhifanggou watershed was in a health state during the period of 1938 to 1947,then turned to be subhealth.The health state became better since 1963,and became healthy again in 1990.Based on the analysis of the land-use structure and the recovery characteristics,the curves of R-SAEWI and relative land use structure index （R-SI） revealed the responding relationship beteew SAEWI and land use structure,which proved that the human activity had strong impacts on SAEW.Meanwhile,the time lag appeared in the response curve was discussed. The assessment results agree quite well with those reported by previous investigators,which showed that the method presented in this paper is of primary use for the SAEW prediction and the practice of soil and water conservation.

关 键 词：土壤抗水蚀能力 土地利用变化 生态系统健康 承载力 黄土丘陵区小流域 

分 类 号：S157[农业科学—土壤学]