侵蚀性雨型分类及不同植被类型对棕壤坡面土壤侵蚀的影响

Effects of Erosive Rainfall Patterns and Different Vegetation Types on Soil Erosion in Slope with Brown Soil

为探讨不同雨型下的植物措施对棕壤坡面土壤侵蚀特征的影响,利用k-均值聚类方法将2018—2019年山东省泰安市下港坡面径流场16次侵蚀性降雨进行分类,结合径流场产流、产沙等监测数据,分析了不同雨型对4种植被措施下坡面土壤侵蚀的影响。结果表明:(1)以降雨历时、降雨量和平均雨强为特征指标,侵蚀性降雨可分为A类(长历时、大雨量、大雨强)、B类(中历时、中雨量、中雨强)和C类(短历时、小雨量、小雨强)3种雨型。(2)与种植玉米相比,A、B雨型下,减流量均呈现板栗花生间作>苹果树>李子树的趋势。在土壤流失量方面:A雨型下,与李子树相比,减沙量呈现板栗花生间作>苹果树>玉米的趋势;B雨型下,与玉米相比,板栗花生间作的减沙率为84.2%,李子树的减沙率为31.2%,苹果树的减沙率为85.1%;C雨型下,减沙量呈现苹果树>李子树>板栗花生间作的趋势。(3)种植玉米的坡耕地土壤侵蚀情况最为严重,平均每年的土壤流失量为18.04 t/hm2;与之相比,板栗花生间作可降低79.57%的土壤侵蚀率,苹果树和李子树可分别降低73.36%,18.55%的土壤侵蚀率。综上,板栗花生间作与其他植物措施相比具有一定优势,尤其适合应对长历时、大雨量、大雨强的A类侵蚀性降雨,减流、减沙效果明显。

In order to explore the effects of plant measures on characteristics of soil erosion in slope under different rainfall patterns, the data of sediment yield and sediment yield under 16 events of erosive rainfall in 4 plots of Xiagang slope runoff field, Tai′an City, Shandong Province during 2018—2019 were analyzed. The results show that:(1) with rainfall duration, rainfall and average rainfall intensity as characteristic indexes, erosive rainfall can be divided into three categories: category A(long duration, heavy rainfall and heavy rain intensity), category B(medium duration, medium rainfall and moderate rain intensity) and category C(short duration, small rainfall and light rain intensity);(2) compared with maize planting, the decreasing flow decreased in the order: chestnut and peanut intercropping>apple tree>plum tree showed the trend under both A and B rainfall types;in terms of soil loss, compared with plum trees, the sediment reduction showed the trend of chestnut and peanut intercropping>apple tree>maize under rain pattern A;under B rainfall type, the sediment reduction rates of chestnut peanut intercropping, plum tree and apple tree were 84.2%, 31.2% and 85.1%, respectively;under the rainfall type C, the sediment reduction showed the trend of apple tree>plum tree>chestnut and peanut intercropping;(3) soil erosion was the most serious in the sloping farmland planted with maize, and the average annual soil loss was 18.04 t/hm~2;in comparison, chestnut and peanut intercropping could reduce soil erosion by 79.57%, apple tree and plum tree could reduce soil erosion by 73.36% and 18.55%, respectively. In conclusion, chestnut-peanut intercropping has certain advantages compared with other plant measures, especially suitable for dealing with class A erosive rainfall with long duration, heavy rainfall and heavy rain intensity, and the effect of reducing flow and sediment is obvious.