汾河上游不同土地利用方式对坡地水土流失的影响

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(P0.05)。在裸地、黄刺玫及草地小区,I30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,I30和产沙量之间无显著相关。

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

Based on field observations of runoff and sediments of water and soil erosion under different land uses 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 I₃₀ and runoff yield in bare land, Rosa xanthina Lindl. and grassland. There was no significant correlation between I₃₀ and sediment yield in bare land, Pinus tabuliformis Carrière, Rosa xanthina Lindl., and slope farmland.