黄土丘陵沟壑区不同草本植物生长期植物纤维毯对沟道边坡产流产沙的影响

为探究植物纤维毯在黄土丘陵沟壑区的适用性以及不同植物生长期植物纤维毯的水土保持效益,以内蒙古呼和浩特市清水河县为研究区,采用野外人工模拟降雨试验方法,对植物生长期为58,81,132天的直播草本边坡和植物纤维毯边坡径流产沙进行模拟试验。结果表明:(1)植物纤维毯护坡措施可显著延长边坡产流时间,并且产流时间随着植物生长期的增加而增加。在植物生长期为58,81,132天时,植物纤维毯边坡产流时间分别为86,110,243 s,明显大于裸坡(50,70,111 s)和直播草本边坡(73,83,123 s)。(2)随着植物生长期的增加,植物纤维毯边坡径流量从13 125 mL降至5 478 mL,产沙量从73 g降至22 g;直播草本边坡径流量从25 573 mL降至14 340 mL,产沙量从201 g降至82 g。(3)植物纤维毯护坡措施减流效益为55%～78%,减沙效益为71%～89%。(4)坡面植被高度、盖度是植被生长状况中影响径流产沙的主要因子,径流量、产沙量与植被高度和盖度呈多元线性函数关系。植物纤维毯能够有效降低黄土丘陵沟壑区沟道边坡土壤侵蚀,减少产流。

Effects of Plant Fiber Blankets of Different Herbaceous Plant Growth Stages on Runoff and Sediment Yield in the Loess Hilly and Gully Region

In order to explore the applicability of plant fiber blankets and its soil and water conservation benefits with different plant growth periods in the hilly and gully regions of the Loess Plateau, an artificial rainfall simulation experiment was conducted in Qingshuihe County, Inner Mongolia, to study the runoff and sediment yield in direct-seeded herbaceous slopes and plant fiber blanket slopes with 58, 81 and 132 days plant growth periods. The results were as follows: (1) Plant fiber blanket slope protection measures could significantly extend the slope runoff time, and the runoff time increased with the increases of plant growth periods. When the plant growth period was 58, 81, 132 days, the plant fiber blanket slope runoff time was 86, 110, 243 s, which was significantly longer than the bare slope (50, 70, 111 s) and the direct-seeded herbal slope (73, 83, 123 s). (2) With the increases of plant growth periods, the runoff of the slope of plant fiber blanket decreased from 13 125 mL to 5 478 mL; sediment yield decreased from 73 g to 22 g; the runoff of the direct seeding herb slope decreased from 25 573 mL to 14 340 mL, and the sediment yield decreased from 201 g to 82 g. (3) The runoff reduction of plant fiber blanket slope protection measures were 55%~78%, and sediment reduction were 71%~89%. (4) Slope vegetation height and coverage were the main factors affecting runoff and sediment yield in vegetation growth conditions. There were multivariate linear functions relationships among runoff, sediment yield, height and coverage. The plant fiber blanket could effectively reduce soil erosion and reduce runoff in the gully slope of loess hilly and gully region.