坡面水蚀比尺模型室内外相似性试验研究

对野外和室内在25°陡坡、人工降雨条件下的侵蚀产沙试验进行了对比分析,结果表明:在降雨强度相同或相近时,室内外降雨侵蚀力非常接近,但是土壤可蚀性却相差4倍左右;当其它影响因素如土壤容重、土壤前期含水量等相同或相近时,仅要达到累计侵蚀产沙量的相似,室内坡面模型可以采用2∶1的几何比尺,该比尺下室内外侵蚀产沙量的误差小于10%;从侵蚀产沙速率来看,室内外试验侵蚀产沙的过程差异较大;室内外试验都是降雨强度越大,坡面产生的细沟数量越多,并且细沟的平均长度、宽度、深度也越大;但要做到室内外坡面形态发育的相似还存在较大难度。

Study on Similarity to Laboratory and Field Experiment of Scale Model on Interrill Erosion

By comparing the laboratory and field sediment yield on the slope of 25 degree under the artificial rain,the results show that: when rainfall intensity are same or close,laboratory and field rainfall erosivity are extremely close and soil erodibility differs from 4 times;when the other factors like soil bulk density,soil moisture content are same or close and if the accululated sediment yields similarity is only got,the scale of the field model is two times of the laboratory model.The absolate error of the accumulated sidement yields is less than 10 percent;The process of the laboratory sediment yeild of erosion differs from the field very much based on sediment yield rate of erosion;Under the laboratory and the field experiment,the rills on the slope are more when the rainfall intensity is bigger.And the average length,width,depth of the rills are all bigger.But there are many difficulties in the laboratory and field experimental similarity to the slope shape growth.