水保所知识产出(1956---)知识库

 为研究黄土丘陵沟壑区多种因素对撂荒草地入渗特征的影响，采用野外自然降雨观测法，研究不同降雨特
征(降雨量、平均雨强、降雨历时和最大 30 min 雨强(I 30 ))、土壤前期含水量、坡长(10 m、20 m、30 m、40 m 和
50 m)和植被盖度条件下土壤入渗特征差异，通过灰色关联度法判断影响撂荒草地入渗特征的主导因子。结果表
明: ① 入渗量随降雨量、降雨历时和 I 30 增加而增大(Ｒ 2 ＞0． 55，P ＜0． 01); 入渗补给系数随降雨量、I 30 和平均雨
强增大而减小(Ｒ 2 ＞0． 12，P ＜0． 05); 平均入渗率随降雨强度、I 30 增加而递增(Ｒ 2 ＞0． 53，P ＜0． 01)。② 入渗量和
平均入渗率随前期含水量增加而减少，入渗补给系数随之增加而增大(Ｒ 2 ＞0． 13，P ＜0． 05)。③ 入渗量、入渗补给
系数和平均入渗率总体随坡长增加而增大(Ｒ 2 ＞0． 56，P ＜0． 01)，但在坡长 30 m 和40 m 之间存在临界坡长。④ 在
入渗效率较高的情况下，植被对土壤入渗的影响并不显著，降雨特征和坡长成为主导因子。

To explore the influence of various factors on the infiltration characteristics of abandoned grassland in the
loess hilly and gully region of the Loess Plateau，a natural rainfall field observation method was used to study the in-
fluence of rainfall characteristics (rainfall，average rainfall intensity，rainfall duration and the maximum 30 min rain-
fall intensity (I 30 ))，antecedent soil water content，slope length (10 m，20 m，30 m，40 m and 50 m)，and veg-
etation coverage on soil infiltration characteristics． The grey correlation method was used to determine the dominant
factors affecting the infiltration characteristics of the abandoned grassland． It was found that the infiltration amount in-
creased significantly with increasing rainfall，rainfall duration and I 30 (Ｒ 2 ＞ 0． 55，P ＜ 0． 01)． The infiltration sup-
plement coefficient decreased with increasing rainfall，I 30 and average rainfall intensity (Ｒ 2 ＞0． 12，P ＜0． 05)． The
average infiltration rate increased with increasing rainfall intensity and I 30 (Ｒ 2 ＞0． 53，P ＜0． 01)． The infiltration a-
mount and average infiltration rate decreased with the increase of antecedent soil water content，whereas the infiltra-
tion supplement coefficient increased with the increase of antecedent soil water content (Ｒ 2 ＞0． 13，P ＜0． 05)． The
infiltration amount，infiltration supplement coefficient and average infiltration rate increased as the slope length in-
creased (Ｒ 2 ＞0． 56，P ＜0． 01)． However，there was a critical slope length between 30 m and 40 m． Ｒainfall char-
acteristics and slope length were the main factors affecting soil infiltration，and the effect of vegetation coverage on soil
infiltration was not significant as the infiltration efficiency was high．