黄土高原南部地区人工模拟暴雨条件下不同坡度谷子坡耕地产流产沙过程

以谷子坡耕地为研究对象,通过人工模拟降雨试验,探究不同生育期谷子在不同坡度下对坡耕地坡面侵蚀过程的影响,揭示黄土高原地区坡耕地侵蚀过程特征和机理.根据试验区现行退耕还林(草)政策、降雨特点及谷子生长特性,在80 mm/h降雨强度和4个坡度(3°,5°,10°,15°)条件下分别对4个生育期(幼苗期、拔节期、抽穗期、灌浆...

Runoff and Sediment Yield Processes in Millet Cultivated Land with Different Slopes Under Artificial Simulated Rainstorm in the Southern Loess Plateau

Taking millet sloping farmland in the Loess Plateau as the research object, through artificial simulated rainfall test, the influence of millet at different growth stages on the erosion process of sloping farmland with different slope gradients was explored, and the characteristics and mechanism of the erosion process of sloping farmland in the Loess Plateau were revealed. According to the current policy of returning cultivated land to forest (grass), rainfall characteristics and millet growth characteristics in the experimental area, artificial rainfall simulation was conducted on millet planting slopes at four growth stages (seedling stage, jointing stage, heading stage and grout stage) under the conditions of 80 mm/h rainfall intensity and four slopes (3°, 5°, 10° and 15°). The results showed that millet had a significant impact on the erosion process of sloping farmland. With the growth of millet, the initial runoff yield time increased, the runoff yield curve tended to be stable in shorter time, and the average runoff and sediment yield intensity decreased, and the runoff and sediment reduction benefit of millet increased gradually. On the 3° and 15° slopes, the initial runoff yield time increased from 5.25 and 1.40 min on bare ground to 12.70 and 7.63 min at the grouting stage, respectively. On the 3° and 15° slopes, the average runoff yield strength decreased to 0.52 and 0.78 L/(m²·min) during the grouting period, and the average sediment yield strength decreased to 0.83 and 2.07 g/(m²·min) during the grouting period. Compared with bare field, runoff and sediment yield decreased by 12.27%~48.24% and 19.90%~84.00%, respectively, from seedling stage to grouting stage. The results could provide a reference for revealing the erosion mechanism of millet sloping farmland in the Loess Plateau and provide a scientific basis for regional high-quality development.