遂宁组母质封禁后的土壤侵蚀规律分析

Analysis of Soil Erosion on Suining Group Parent Material After Closing Management

通过遂宁市水土保持试验站母质侵蚀观测场长期连续观测试验,收集1991—2000年资料,采用数据分析方法,对遂宁组紫色土母质侵蚀规律进行了研究。结果表明:(1)母质侵蚀区在封禁10 a内的年际地表径流模数与年际降雨量变化趋势一致,而土壤侵蚀模数总体呈现逐年下降趋势;(2)径流深与降雨量呈正相关,与降雨时间呈负相关。(3)降雨量和平均降雨强度两因子对土壤侵蚀量影响不显著,土壤侵蚀量与地表径流深在封禁期前4 a内能建立回归方程。由此认为,采用封禁管理来防治紫色土母质侵蚀可行,封禁至少8 a以上土壤侵蚀强度类型才由剧烈侵蚀逐渐转化为轻度侵蚀。

Through continuous field observation of soil erosion in the Soil and Water Conservation Station of Suining, processes of soil erosion on purple parent material of the Suining group were studied by collecting the data from 1991 to 2000 and using the method of data analysis. Results showed that annual runoff module from soil erosion plots on the parent material closed for 10 years changed with annual rainfall amount, but on the whole, annual soil erosion module had a tendency to decrease year by year. Runoff depth was positively related to rainfall amount, and inversely related to rainfall duration. A regression equation for the relationship between runoff depth and rainfall amount was established, and the critical rainfall amount that can induce runoff was found to be 15.85 mm. Rainfall amount and mean rainfall intensity did not significantly influence soil erosion amount. During the first 4 years, the regression equation could be formed between soil erosion amount and runoff depth, and the critical runoff depth that can induce a large amount of soil erosion was 9.05 mm. It is evident that the closing management may prevent and cure soil erosion on the purple parent material, and soil erosion gradually changes from severe degree to light degree after closing for at lest 8 years.