摘要
通过对陕北黄土高原吴起县退耕地5个不同植被类型径流小区降雨对径流产沙影响的分析,研究退耕还林后不同植被类型的水土保持效应。结果表明:(1)降雨量与雨强对径流量的影响显著;小区建立初期5个径流小区的产流状况从大到小为油松>草地>沙棘+油松(Ⅱ)>沙棘+油松(Ⅰ)>沙棘;随着植被生长,产流从大到小为草地>沙棘+油松(Ⅱ)>沙棘>油松>沙棘+油松(Ⅰ)。随着林分郁闭度的增大,降雨与径流量的相关性在减少。(2)径流量与雨强对产沙量的影响显著;小区建立初期5个径流小区的产沙量从大到小顺序为油松>沙棘+油松(Ⅱ)>草地>沙棘>沙棘+油松(Ⅰ);随着植被生长,产沙量从大到小为草地>油松>沙棘>沙棘+油松(Ⅱ)>沙棘+油松(Ⅰ)。随着植被生长,产沙量基本趋于稳定。(3)坡度对径流产沙的影响显著。同一场降雨,植被类型相同,坡度大的径流量大、产沙量也大;坡度相近的小区,小区建立初期径流产沙量从大到小为油松>沙棘+油松(Ⅱ)>草地>沙棘>沙棘+油松(Ⅰ);随着植被生长,径流产沙从大到小为草地>油松>沙棘>沙棘+油松(Ⅱ)>沙棘+油松(Ⅰ)。因此,退耕还林后,林草植被恢复有效减少了水土流失,在造林初期,沙棘纯林的水土保持效果最为显著,随着植被生长,(沙棘+油松)混合林地的水土保持效应效果最佳。
According to the analysis of the five different vegetation types runoff plots precipitation which had impacts on runoff and sediment yield in Wuqi county abandoned lands on the Loess Plateau of northern Shaanxi, the effects of soil and water conservation on the different vegetation types of returning farmland to forest were found out. The results showed： （1）Rainfall and rain intensity had significant influence on the runoff. At the initial stage establishment of the runoff plots, Hippophae rhamnoides runoff plot was the best for reducing the runoff; with the growth of the plants, Pinus tabulacformis ＋ Hippophae rhamnoides （ I ） runoff plot was the best for reducing the runoff. With the canopy density increased, the relativity of rainfall and rain intensity for runoff decreased. （2）Rainfall and rain intensity had significant influence on the sediment yield. Pinus tabulacforrnis ＋ Hippophae rhamnoides （ I ） runoff plot was the best for reducing the runoff. With the growth of vegetation, the sediment yield scope was nearly stable. （3）Slope had significant influence on the runoff and sediment yield. Under the same rainfall, runoff and sediment yield became bigger and bigger with the rainfall increased. When the slope was nearly same, Pinus tabulacformis＋Hippophae rhamnoides（ I ） runoff plot was the best for reducing the runoff and sediment yield. Consequently, after returning farmland to forest, vegetation recovery had reduced the soil and water loss efficiently. At the initial stage establishment of the runoff plots, Hippophae rhamnoides pure forest was the most significant for soil and water conservation; with the vegetation growth, Pinus tabulacformis ＋ Hippophae rhamnoides mixed forest was the most significant for soil and water conservation.
出处
《水土保持学报》
CSCD
北大核心
2013年第2期26-30,35,共6页
Journal of Soil and Water Conservation
基金
国家“十二五”科技支撑计划项目“黄土及华北土石山区水土保持林体系构建技术研究与示范”(2011BAD38B06)
国家重点基础研究发展计划资助项目(2009CB825103)
关键词
植被类型
降雨量
降雨强度
径流量
产沙量
vegetation types
rainfall
rain intensity
runoff
sediment yield
