摘要
通过人工降雨来研究太行山低山丘陵区典型地表类型下的降雨入渗产流规律。结果表明:(1)不同地表类型,地表产流特征不同。主要表现在:降低坡度主要推迟产流开始时间,而植被能够推迟整个径流过程;增加植被覆盖度和降低坡度能够明显降低产流量,延缓产流时间、降低径流速率;不同地表类型的地表径流速度与径流稳定前降雨历时具有明显的对数函数关系。在以0.64mm/min左右的降水强度持续80min后,斜坡径流小区不同地表类型径流系数大小顺序为:斜坡裸地>没有枯枝落叶的斜坡灌木>斜坡草地>有枯枝落叶的斜坡灌木。与裸地相比,后面3种地表类型的地表径流量分别减少了33.7%(8.3mm),49.2%(12.1mm)和75.2%(18.5mm)。(2)不同植被、枯枝落叶在降低地表产流量的同时也增加了深层土壤中的入渗量。斜坡裸地下渗到20cm以下的水量仅为降雨的6.0%,明显小于有植被条件下的23.3%～32.5%。灌木下的枯枝落叶能够增加土壤入渗量20%左右,土层20cm以下入渗量增加8%。
An artificial rainfall experiment was conducted to clarify the characteristics of rainfall--infihra tion--runoff under typical ground surfaces conditions in the hilly regions of Taihang Mountain. The resuits showed that：（1）Characteristics of runoff generation was apparently different for various ground surfaces, which was mainly demonstrated by following results： decreasing slope gradient delayed the time of runoff generation, while vegetation actually postponed the whole runoff process. Increasing vegetation cover and reducing slope gradient significantly reduced runoff volume and rate, and also delayed runoff generation. Under every special ground surface, the rate of surface runoff is logarithmically related with rainfall duration from runoff commencing to stabilization. After an artificial precipitation with an intensity of 0.64 mm/min and a duration of 80 minutes, the order of runoff coefficient for different land covers of slope was： bare land〉shrubs without alitterlayer〉grassland〉shrubswith alitterlayer. Compared with bare land, the later three ground surfaces reduced runoff by 33.7% （8.3 mm）, 49.2%（12. 1mm） and 75.2%（18.5 mm） respectively. （2）As different land cover and surface litter combinations reduced runoff amount, actually promoted more rainwater infiltrating to the deeper soil layer. Only 6.0% of rainfall infiltrated to the soil below 20 cm depth in bare land, which was significantly less than 23. 3%-32. 5% of rainfall in vegetated conditions. The litter layer underlying shrubs increased 20% of rainwater infiltrated to soil and 8% to the soil below 20 cm depth.
出处
《水土保持研究》
CSCD
北大核心
2009年第5期35-39,共5页
Research of Soil and Water Conservation
基金
林业科技支撑计划(2006BAD03A02)
国家科技支撑计划(2007BAD69B03)
关键词
地表径流
人工降雨
降雨分配
植被类型
surface runoff
artificial rainfall
rainfall distribution
vegetation types
