The bulk density was 1 . 2 g cm - 1 . the soil contents about 60 % of silts and about 15 % of clays . a slope adjustable flume of 3 by 8 m was subdivided into 15 mini - flumes of 0 . 2 by 8 m 土壤颗粒以粉沙为主,粉沙粒占总量的60左右,粘粒约占15左右,容重约为1 . 2gcm ~ ( - 1 ) ,试验前将土样风干并过1 1cm的粗筛。