A simple model for the transport of soil-dissolved chemicals in runoff by raindrops

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• 作者：Wencai Dong^a ; ^b ; Quanjiu Wang^c ; ^b ; ^{wquanjiu@163.com} ; Beibei Zhou^c ; Yuyang Shan^b
• 关键词：Raindrop impact ; Solute transport ; Runoff ; Soil erosion
• 刊名：Catena
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：101
• 期：Complete
• 页码：129-135
• 全文大小：858 K

文摘

The development of a physically based model to simulate the transport of soil solutes in runoff has provided a better understanding of the mechanisms of transport and has assisted in the development of effective methods to control nutrient loss from soils and the pollution of waterways. A refined model has been applied to experimental data in which the presumed exchange layer was replaced by a mixing zone. Assuming that the exchange rate is controlled by raindrop splash, the effects of diffusion can be neglected and the exchange rate, k_m, can be replaced by the variable e_r, the raindrop-induced water transfer rate, removing the need to calibrate k_m. To calibrate our model, laboratory experiments were conducted on disturbed loessial soil with three initial soil-moisture contents (5 % , 15 % , and 20 % , measured gravimetrically) under three rainfall intensities (60, 96, and 129 mm h^? 1) and three slope gradients (5, 15, and 25¡ã). The model's simulated data agreed well with the experimental data, demonstrating that the refined model captured the temporal behaviour of solute transport in the runoff. This study provides a new approach to the modelling of chemical transport by investigating the effects of raindrops on sediments from soil in surface runoff.