黄土丘陵区不同土地利用方式降雨产流试验研究

在延安燕沟试验区建立草地、刈割草地、翻耕草地、灌木地、刈割灌木地、翻耕灌木地径流小区,通过对30场人工模拟降雨产流试验中产流历时、径流强度、径流深、入渗率数据的分析,得出草灌地产流历时远大于翻耕地和刈割地。翻耕灌木地径流强度及波动幅度最大,为翻耕草地的1.5倍、草地的3.4倍、灌木地的15.7倍。在各次降雨过程中,草地平均径流深、入渗率分别为17.1 mm和75%,刈割草地为25.3 mm和62%,翻耕草地为38.4 mm和35.6%,灌木地为3.2 mm和97%,刈割灌木地为5.6 mm和92%,翻耕灌木地为46 mm和35%。研究结果表明,植被能有效地拦蓄径流,而对草灌地的破坏可引发黄土丘陵区严重的水土流失。

Test on Rainfall-runoff with Different Land Use Patterns in Loess Hilly Region

It establishes the runoff plots of grassland,cradled grassland,ploughed grassland,bush-land,cradled bush-land and ploughed bush-land in Yangou experimental area in Yan'an.The duration of runoff yield of grass-bush land is far greater than that of the cradled and ploughed lands based on the analysiss datas of duration of runoff yield,runoff intensity,runoff depth and infiltration rate which are obtained from 30 artificial rainfalls.The runoff intensity and fluctuation amplitude of ploughed bush-land is the maximum,1.5 times of ploughed grassland,3.4 times of grassland and 15.7 times of bush land.During each rainfall,the mean runoff depth and infiltration rate of grassland are 17.1 mm and 75%,cradled grassland 25.3 mm and 62%,ploughed grassland 38.4 mm and 35.6%,bush land 3.2 mm and 97%,cradled bush-land 5.6 mm and 92%,ploughed bush-land 46 mm and 35% respectively.The outcomes show that vegetation can impound runoff effectively and the damage to grass-bush land can cause serious soil and water loss in loess hilly region.