入渗水量对重庆四面山草地优先流影响的定量评价

Quantitative Evaluation of Effects of Infiltration Amounts on Preferential Flow in Grassland in Simian Mountain of Chongqing

以重庆四面山草地为研究对象,通过野外染色示踪试验,借助图像处理技术、方差分析、相关性分析及变异性分析等方法,分析3种不同入渗水量(20,40,60mm,对应的样地编号分别为G20,G40,G60)对土壤优先流的影响并进行定量评价。结果表明:(1)染色面积比基本上随着土层深度的增加而减小,其中G20和G40的染色面积比分别从3cm和12cm处开始显著下降;(2)总染色面积比和优先流长度指数与入渗水量呈显著正相关(P<0.01);(3)入渗水量的增加可以促进水分向更深层运动,最高可达60cm;(4)优先流区染色面积比和最大入渗深度的非均匀性随着入渗水量的增加而减小,其变异性系数的变化分别为1.88~0.47和0.52~0.07,但入渗水量对实际入渗深度的影响则更为复杂。

To quantitatively evaluate the effects of three different infiltration amounts on soil preferential flow,the morphological image processing technology,statistical sample variability analysis,variance analysis,and correlation analysis were used in this study.G20,G40,and G60 were taken to represent these plots with three different infiltration amounts（20 mm,40 mm,and 60 mm respectively）.Dyeing experiments with Brilliant Blue FCF（C.I.Food Blue 2）were conducted in grassland in Simian Mountain of Chongqing.The results showed that：（1）Dye coverage generally decreased with the increasing soil depth,and sharp decreases were found at the depths of 3 cm in G20 and 12 cm in G40,respectively.（2）The total dye coverage and length index of preferential flow were positively correlated with infiltration amounts（P〈0.01）.（3）Water infiltration was promoted to deeper soil layers as the infiltration amounts increased,and the maximum depth of water infiltration reached 60 cm.（4）The non-uniformity of dyed coverage in preferential flow area and the maximum infiltration depth decreased with the increasing infiltration amounts with their variation coefficients ranging from 1.88 to 0.47,and 0.52 to 0.07,respectively.However,the effects of infiltration amounts on actual infiltration depth was even more complicated.