江苏省沿海平原沙土区典型河沟边坡土壤侵蚀试验研究

为探明江苏省沿海平原沙土区河沟边坡土壤侵蚀过程并建立预测模型,在4个坡度和2个雨强条件下,对江苏省沿海平原沙土区典型河沟边坡土壤开展人工模拟溅蚀试验和微区模拟降雨试验,了解河沟边坡土壤溅蚀特征,明确河沟边坡产流产沙过程,并利用传递函数方法分别建立了溅蚀率、产流强度和产沙强度的估算模型。结果表明:(1)河沟边坡土壤溅蚀率随降雨强度及坡度的增大而增加,土壤溅蚀率与降雨强度和坡度之间呈线性关系;(2)河沟边坡的产流过程总体上呈现出先增大后波动稳定的趋势,产流强度随着坡度的增大而减小;产沙过程总体上呈先快速增加后波动减小,最后趋于稳定的趋势,产沙强 度随着坡度的增大而增加;产流强度和产沙强度均随雨强的增大而增大;(3)利用传递函数建立的方程预测溅蚀率,产流强度和产沙强度具有较高的精度,方程的调整R²分别可达0.97,0.91和0.72。研究结果可加深对江苏省平原地区河沟边坡土壤侵蚀规律的认识,并为建立土壤侵蚀预报模型和水土流失治理提供理论依据。

Experimental Study on Soil Erosion of Typical Riverbank in Coastal Plain Sandy Area of Jiangsu Province

The purpose of this study was to investigate the soil erosion process on the riverbank and establish the prediction models. Under the conditions of four slope gradients and two rainfall intensities, artificial simulated splash erosion test and micro area simulated rainfall test were carried out on typical riverbank in coastal plain sandy soil area of Jiangsu Province, so as to understand the characteristics of soil splash erosion, clarify the production process of runoff and sediment. The estimation models of splash erosion rate, runoff intensity and sediment yield intensity were established using the transfer function method. The results showed that:(1) The soil splash erosion rate on the riverbank increased with the increasing of rainfall intensity and slope gradient. There was a linear relationship between soil splash erosion rate and rainfall intensity and slope gradient. (2) The runoff production process on the riverbank generally showed a trend of increasing first and then fluctuating and stabile, and the runoff production intensity decreased with the increasing of slope gradient. In general, the sediment yield process increased rapidly first and then decreased with fluctuation, and finally tended to be stable. The sediment yield intensity increased with the increasing of slope gradient. The intensity of runoff and sediment both increased with the increasing of rainfall intensity. (3) The equation established by transfer function had high accuracy in predicting splash erosion rate, runoff intensity and sediment yield intensity, and the adjustment R² of the equation could reach 0.97, 0.91 and 0.72, respectively. The results could deepen the understanding of the law of soil erosion on riverbank in plain area of Jiangsu Province, and provide a theoretical basis for establishing soil erosion prediction model and soil erosion control.