为探寻坡地土壤饱和导水率(K s )的田间测量方法，利用基于水平地面发展而来的单环双水头法、单环单水
头法和单环 BEST 法测量 3 种类型土壤(风沙土、黄绵土和塿土)的 K s ，分析坡度(0°、5°、10°、15°、20°)对 3 种测量
方法所测定 K s 值的影响。结果表明: 3 种方法测定的不同类型土壤 K s 大小顺序一致，但是单环 BEST 法显著高于
单环双水头法与单环单水头法(P ＜0. 05);单环双水头法测得 K s 值均随坡度的增加而增加，而单环 BEST 法测量结
果与之相反，随着土壤质地由粗变细，坡度的影响程度(回归线斜率)有降低趋势;单环单水头法(10 cm)测量 K s 值
与单环双水头法完全一致，在土壤水力学参数确定后，可替代单环双水头法。当坡度 ＜ 10°时，3 种方法测量的 K s
与无坡度 K s 无显著差异，当坡度 ＞10°时，差异显著(P ＜0. 05)。因此，坡度显著影响 3 种测量方法测算的 K
s 值，单
环 BEST 法不适合测量坡地 K s ，当坡度 ＜10°时，单环双水头法与单环单水头法(10 cm)可测量计算 3 种类型土壤
K s 。
其他摘要
［Background］Soil saturated hydraulic conductivity (K s ) of sloping field is a key parameter
to predict soil and water losses，but K s is mostly measured on the flat land． Therefore，directly measuring
saturated hydraulic conductivity on slopes is practically important． The objective of this paper is to study
the effect of slope gradient on K s by three single-ring infiltrometer methods in order to select a suitable
method for slope land． ［Methods］ The slope gradients of 0，5°，10°，15° and 20° in sandy soil，
Loessial soil and Lou soil were selected and K s was measured by three single-ring infiltrometer methods
(i． e． ，two-ponding depth，one-ponding depth and BEST methods)，which usually were used for flat
lands． All measurements were conducted on undisturbed soil． ［Ｒesults］1) On flat soil surface，all
three methods obeyed the same order for K s of different soils as sandy soil ＞ Loessial soil ＞ Lou soil．The K s of three soils by single-ring BEST infiltrometer were 2. 9，2. 1 and 4. 5 times，which were larger
than those by single-ring two-ponding depth infiltrometer． If cutting-ring infiltrometer was taken as
standard，single-ring BEST infiltrometer significantly overestimated the K s of the Loessial and Lou soil，
but the results by single-ring two-ponding depth infiltrometer and single-ring one-ponding depth (10 cm)
infiltrometer were close to that by cutting-ring infiltrometer． 2) K s measured by single-ring two-ponding
depth infiltrometer increased with the increase of slope gradient and there was a significant linear
correlation between them． The K s of three soils by single-ring BEST infiltrometer decreased with the
increase of slope gradients and this method was affected distinctly by slope gradient due to the change of
the ponded water area inside the ring． 3) Under flat ground condition，the results of single-ring one-
ponding depth (10 cm) infiltrometer were comparable to single-ring two-ponding depth infiltrometer，but
the single-ring one-ponding depth (5 cm) infiltrometer overestimated the results． 4) In sandy soil，
Loessial soil and Lou soil，there was no significant difference of K s between slope ＜10° and flat land by
above 3 methods，but significant while slope ＞10° (P ＜0. 05)． ［Conclusions］Therefore，single-ring
BEST infiltrometer is not suitable for measuring K s in sloping field． Single-ring two-ponding depth
infiltrometer or single-ring one-ponding (10 cm) depth infiltrometer can be used to correctly measure K s if
the slope is ＜10°． Furthermore，the calculating equations for saturated hydraulic conductivity by these
sing-ring methods should be revised for the three soils in the loess regions if the slope gradient is ＞10°．
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