汾河上游不同土地利用方式对坡地水土流失的影响

Effects of Different Land Uses on Water and Soil Erosion in the Upper Area of Fen River

以汾河上游阳坡小流域为研究区,在2015—2017年进行了天然降雨条件下的坡面产流产沙小区试验,结果表明:(1)研究区的侵蚀性降雨在年内和年际间分布很不均匀。少数几次强降雨对降雨侵蚀力的贡献很大。(2)不同侵蚀性降雨条件下,鱼鳞坑+乔木或灌木拦蓄径流或泥沙能力最强,裸地最弱;坡面产流量大小依次为:裸地>坡耕地>草地>油松>黄刺玫>鱼鳞坑+油松>鱼鳞坑+黄刺玫。坡面产沙量大小规律为:鱼鳞坑+乔或灌<草地<乔或灌<坡耕地<裸地。(3)随着雨量增加,各植被小区的径流调控率和泥沙调控率均呈下降趋势;相近雨量时,随着雨强的增加,径流调控率和泥沙调控率明显下降。(4)各小区的降雨量和产流量、产流量和产沙量之间呈现显著正相关(P<0.05)。在裸地、黄刺玫及草地小区,I 30与产流量之间是均无显著相关。在裸地、油松、黄刺玫、耕地小区,I 30和产沙量之间无显著相关。

Based on field observations of runoff and sediments of water and soil erosion under different land u ses generated on runoff plots and rainfall data from^2015 to 2017,we studied quantitatively the effects in upper area of Fen River.The results showed that:(1)The distribution of erosion rainfall in the study area was very uneven within a year and between years.Several times of heavy rainfall contributed a lot to the erosion of rainfall.(2)Under different rainfall conditions,the runoff or sediment holding capacity of the fish-scale pit+trees or shrubs was the strongest,while the bare land was the weakest.The runoff yield on slope was as follows:bare land>slope farmland>grassland>Pinus tabuliformis Carrière>Rosa xanthina Lindl.>fish-scale pit and Pinus tabuliformis Carrière>fish-scale pit and Rosa xanthina Lindl..The slope sediment yield was:fish-scale pit and trees or shrubs<grass<trees or shrubs<slope farmland<bare land.(3)With the increase of rainfall,both the runoff regulation rate and sediment regulation rate of each vegetation plot showed a downward trend.With the increase of rainfall intensities,both regulation rates decreased obviously.(4)There were significant positive correlations between rainfall and runoff yield,runoff yield and sediment yield in each plot(P<0.05).There was no significant correlation between I 30 and runoff yield in bare land,Rosa xanthina Lindl.and grassland.There was no significant correlation between I 30 and sediment yield in bare land,Pinus tabuliformis Carrière,Rosa xanthina Lindl.,and slope farmland.