“一坡三带”退耕还林模式水土保持特征研究——以毕节市为例

A Restoration Study of Water and Soil Conservation : The Returning Farmland to Forest Model of " Three Vegetation Zones Arranged on One Slope" -——Take Bijie as an Example

以毕节市三种典型的退耕还林模式即"一坡三带"模式(YP)、纯生态林(柳杉)模式(CS)、纯经济林(核桃)模式(CJ)为研究对象,在不考虑林冠层作用的条件下,通过人工模拟降雨法,分析研究不同退耕模式下对地表产流产沙的影响。结果表明:YP能有效缓解径流,减少径流强度,与CS和CJ这两种模式相比,其径流量分别减少了60.1%和80.1%;径流初始发生时间分别延迟1.57 min和2.08 min;土壤侵蚀量分别降低49.6%和65.5%。可见"一坡三带"退耕还林模式对水土保持效果最为明显,是退耕还林模式中比较适合的植被恢复模式。

Three vegetation zones arranged on one slope（YP）, pure ecological forest（Cryptomeria fortunei Hooibrenk ex Otto et Dietr,CS）,pure economic forest（Juglans regia,CJ） were three typical kinds of returning farmland to forest in Bijie,which were selected in this paper as the research objects, regardless of the role of the Canopy layer. Analysis the influence to the content of sediment and runoff which in the different modes of returning farmland to forest by simulated rainfall. The results indicated that the runoff process was alleviated and amount of run off was reduced using YP, compared to CS,CJ, the amounts of runoff under YP were reduced by60.1% and 80.1%;runoff starting time were slowed down 1.57 and 2.08 min; the amounts of soil; erosion were reduced by 49.6% and65.5%. Therefore, the effect of water and soil conservation under YP were most obvious which is the comparatively suitable mode of vegetation restoration.