To study the characteristics of the distribution of the preferential paths and the affecting factors in the Three Gorges area, four soil profiles were dug to observe the distribution of preferential paths in the Quxi watershed in the Yangtze River basin. The Morisita exponential test method was used to examine the distribution type of preferential paths. The physical properties and infiltration characteristics of the soil were also measured to evaluate their relationship to preferential paths. The results showed that in this area, preferential paths clustered and mainly distributed in the 80-100 cm soil layer, and along the interface between the weathered layer and semi-weathered layer. There were more non-capillary pores in the 83-110 cm layer than in the other layers. It can be derived that most non-capillary pores in this layer were preferential paths caused by geological processes and rotten plant roots. The percentage of coarse soil particles increased with the depth of the soil layer. In the deeper soil layer, the coarse soil particles helped the formation of preferential paths. The fastest steady infiltration rate was observed in the of 83-110 cm layer, which is inferred to be due to the greater number of preferential paths.

通过对三峡库区3种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下地被物调查及其持水试验，分别得到3种森林类型林下地被物最大储水量、吸水速率等水文特征参数。结果表明，栓皮栎纯林林下苔藓层储水量最大，为其风干重的303.1%，松栎混交林林下的为283.8%，马尾松纯林林下的为242.3%。松栎混交林林下枯落物最大储水量为其风干重的282.2%，栓皮栎纯林林下的为262.5%，马尾松纯林林下的为239.3%。经分析拟合，得到林下苔藓层、林下枯落物吸水速率与浸泡时间之间关系式为S=ktn。在同为中龄林条件下，3种森林类型林下苔藓层储水量均高于林下枯落物储水量，而林下地被物储水量随时间变化过程与森林类型无关。

通过对三峡库区三种森林类型（松栎混交林、栓皮栎纯林、马尾松纯林）林下苔藓储量调查分析及其持水特性试验，得到不同森林类型林下苔藓储量、最大持水量、吸水速率等水文特征参数。结果表明，马尾松纯林林下苔藓储量最大（12.93t/hm2），松栎混交林和栓皮栎纯林林下苔藓储量相同 (9.47 t/hm2)。松栎混交林林下苔藓最大持水量为5.36mm，栓皮栎纯林为5.73mm，马尾松纯林为6.26mm。研究结果还表明，三峡库区林下苔藓持水量随时间变化过程与森林类型无关。在只有苔藓覆盖情况下，不同森林类型林内不产生水分下渗和地表径流时的最大降雨量和最大降雨雨强分别为：松栎混交林林地5.36mm，5.820mm/h；马尾松纯林林地6.26mm，7.420mm/h；栓皮栎纯林林地5.73mm，6.060mm/h。

该文通过对三峡库区3种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下枯落物储量调查分析及其持水特性试验，得到不同森林类型林下枯落物储量、最大持水量、吸水速率等水文特征参数。结果表明，栓皮栎纯林林下枯落物储量最大(10.7t/hm)，其后依次为松栎混交林(10.1t/hm2)、马尾松纯林(5.8t/hm2)。松栎混交林林下枯落物未分解层最大持水量为3.09mm，栓皮栎纯林为2.95mm，马尾松纯林为1.46mm。松栎混交林林下枯落物半分解层最大持水量为3.03mm，栓皮栎纯林为2.37mm，马尾松纯林为0.99mm。研究结果还表明，在同为中龄林条件下，三峡库区针阔混交林林下枯落物持水能力大于阔叶树纯林或针叶树纯林林下枯落物持水能力。在只有林下枯落物覆盖情况下，不同森林类型林内不产生水分下渗和地表径流时的最大降雨量和最大雨强分别为：松栎混交林林地6.12mm，7.000mm/h；马尾松纯林林地2.45mm，1.760mm/h；栓皮栎纯林林地5.32mm，6.200mm/h。

通过在长江三峡曲溪小流域花岗岩林地坡面开挖土壤剖面，采用自记雨量计和翻斗式流量计对优先流、土壤渗流及降雨进行了观测。结果表明，在同场降雨中，优先流流速最大可达土壤剖面渗流流速的2166倍，所测优先流总量在土壤剖面渗流总量中占5.5%~7.2%。在其他影响因素相同的条件下，降雨强度越大，优先流产生的时间越早。在一次降雨过程中，降雨历时延长11h时，优先流总量可增加96940cm3。优先流峰值流量与降雨量、降雨峰值呈正相关关系。同时，降雨量的大小还直接影响到优先流在土壤剖面渗流中所占的比重。同场降雨中不同优先流的波形比较相似，即上升阶段的历时较短，表现为较大的正斜率；而降雨停止后，波形呈缓慢的下降趋势，表现为较平缓的负斜率。