黄土丘陵林区开垦地土壤抗冲性的时间变化研究

以黄土丘陵林区 10a径流泥沙观测资料为基础 ,进行土壤抗冲试验 ,分析了林地及其开垦后不同年限土壤的抗冲性能。结果表明 ,林地具有很强的抗冲性能 ,一旦被开垦后 ,随侵蚀年限的增长 ,土壤的抗冲性呈减弱趋势 ,在 3L/min流量下 ,土壤冲刷量从侵蚀 1a的 4.0 1g/L增大到侵蚀 10a的 2 5 .5 1g/L ,加剧了土壤侵蚀发展。相关分析表明 ,土壤的抗剪强度对抗冲性影响最大 ,其次为水稳性团粒和有机质含量。因此 ,退耕还林、恢复和重建植被 ,改善土壤侵蚀环境 ,提高土壤抗冲性 ,能有效地防治土壤侵蚀。

Temporal Change of Soil Anti-scourability of Reclaimed Lands in Loess Hilly Forest Region

Using the 10 year observed data of runoff and sediment in the loess hilly forest region and the field anti scourability tests, the anti scourability in the forest land and the reclaimed lands were analyzed. The results showed that the forest land had the strong anti scourability. After reclaimed, the anti scourability of reclaimed lands had the decrease tendency from 4.01 g/L to 25.51 g/L in the flow of 3 L/min, which would increase the soil erosion intensity. Correlation analyses found that the soil shear strength had the biggest effect on soil anti scourability, and then, the water stable aggregate and the organic content. So it could control effectively soil erosion to return reclaimed lands into forest or grass land, and recover or reconstruct vegetation.