以设在山西省阳高县的大型径流观测场为依托,以2006-2010年的野外实测数据为依据,研究晋北黄土区降雨特征及其对坡地土壤侵蚀的影响。结果表明,晋北黄土区降雨具有明显的季风性降雨特点,7,8月雨量大,雨强也大。5-9月年均降雨量为223.80mm,侵蚀性降雨量为84.64mm,7,8月52.7%的降雨产生的侵蚀量占年侵蚀量的77.4%;大雨(25.0mm≤R24〈50.0mm)的平均次降雨侵蚀量是中雨(10.0mm≤R24〈25.0mm)的2.9倍,总侵蚀量则为中雨的0.5倍,32.2%场次的中雨和大雨产生的侵蚀量占总侵蚀量的72.3%;次降雨量与最大10min雨强的乘积(HI10)和次降雨产沙量呈线性相关,可以用HI10计算降雨侵蚀力;侵蚀性降雨标准为雨量8.47mm或I10为14.24mm/h。防治晋北黄土坡地水土流失的关键期在7,8月份,其关键是防治大雨侵蚀,中雨的危害也不容低估。
Based on the runoff plots located in Yanggao county, Shanxi province and data observed in 2006-- 2010, rainfall characters and its effect on loess slopeland erosion in northern Shanxi province were studied. The results showed the rainfall had monsoon rainfall characteristics in northern Shanxi province, that meant rainfall amount and rainfall intensity tended to be higher in July and August. The average rainfall was 223.80 mm, erosive rainfall was 84.64 mm from May to September. The percentage of rainfall in July and August was 52.7G and that of soil erosion was 77.40//00. Soil erosion of each heavy rainfall(25.0 mm~R24 ~50.0 mm) was 2.9 times that of middle rainfall, however, total erosion of heavy rainfall was 0.5 times that of middle rainfall. Heavy rainfall and middle rainfall which was 32.20/00 of all rainfall events caused 72.3~/oo of total erosion yield. Hllo was correlated with soil erosion, the standards of erosive rainfall was rainfall being 8.47 mm or 110 being 14.24 mm/h. Therefore, the key period was July and August, and the key issue was to control heavy and middle rain erosion to prevent soil and water loss on loess slopeland in northern Shanxi.