具有未完全解冻层坡面产流历时的影响因素

Factors affecting rainfall runoff duration of slope with incompletely thawed layer

春季解冻期土壤坡面包含解冻土层和冻结土层,产流过程有别于非冻融土壤。以我国东北白浆土、黑钙土、棕壤、褐土为研究对象,通过室内降雨模拟试验,分析具有未完全解冻层坡面产流历时的影响因素。结果表明:1)初始土壤含水率是影响产流历时最重要的因素,产流历时随初始土壤含水率的增加而明显缩短,其中,白浆土达到了显著水平;2)产流历时与含水率呈对数函数关系;3)在4种土壤坡面上,降雨强度对产流历时影响不大;4)土壤初始解冻深度对产流历时的影响没有表现出规律性;5)多元回归分析后,推荐春季解冻期产流历时采用指数函数回归;6)侵蚀量峰值出现的时间与产流历时呈负相关;7)白浆土、黑钙土和棕壤侵蚀总量与产流历时呈负相关。

In the spring,runoff process on the freeze-thaw slope is different with that on the non-freezethaw slope,since the former contains thawed layer and frozen layer.Planosol,chernozem,brown and cinnamon soil in northeastern China were selected as research objects,and the indoor rainfall simulation was carried out to study the rainfall runoff duration characteristics with incompletely thawed layer.The results showed that：the initial soil moisture was the most important factor affecting runoff duration,and the runoff duration was significantly shortened with the increase of the initial soil moisture,especially for planosol.The runoff duration was a logarithmic function of soil moisture content.The rainfall intensity and initial thaw depth did not significantly affect rainfall runoff duration.An exponential function was proposed to express the rainfall runoff duration by multiple regression.The longer the rainfall runoff duration lasted,the earlier the peak erosion time appeared.The erosion of planosol,chernozem and brown soil was negatively correlated with the runoff duration.