Estimation of combined splash, interrill, and rill erosion using a hillslope erosion numerical model: An application to dry lands of Chile
Estimation of combined splash, interrill, and rill erosion using a hillslope erosion numerical model: An application to dry lands of Chile
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DOI：
10.2489/jswc.66.2.142
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发表时间：
2011-03
影响因子：
3.9
通讯作者：
A. Dussaillant
中科院分区：
文献类型：
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作者：
A. Dussaillant
坡面侵蚀造成严重的土壤流失，对污染物的迁移起着重要作用，并造成河流和湖泊堤岸。最近的研究估计，全世界现有的45，000座水坝（水坝高度超过15米[49英尺]）截留了全球沉积物通量的25%以上，这些水坝每年将损失其容量的0.5%至1%（Syvitski等人，2005年）。此外，由于人类管理不善造成的土壤侵蚀加剧，导致景观荒漠化加剧。这项工作的目的是为智利“Secano”（旱地）地区侵蚀管理的决策提供一种替代工具。具体而言，数值侵蚀模型与物理基础的开发和测试。虽然该模型是基于以前的发展，它认为降雨溅片和细沟流在一个新的方式，可以很容易地纳入分布式水文模型和/或地理信息系统。它是一个事件模型，将山坡长度划分为元素。水和泥沙可以从上坡进入每个单元，而曼宁方程用于估计平均流速。在该地区收集的新数据是第一次以系统的方式获得的，这些数据来自Secano的实地地块，并用于测试模型。土壤流失监测了一年的标准侵蚀地块与三种不同的治疗方法：传统的旋转（小麦/休闲），免耕轮作（小麦/豆类），和自然草原（加一个裸露的土壤控制每个斜坡）。总事件泥沙流失的治疗预测相当不错，不使用参数校准，获得35%至165%的现场测量和合理的均方根误差的估计，考虑到预期的范围时，模型应用于安装在农田的地块的数据。双因素方差分析结果表明，该模型考虑了坡度和处理的因素，考虑到所有估计值对测量值，结果显示总体r2为0.46。较温和的斜坡和原生植被（草原）的情况下，预测更好。敏感性分析表明，对于片流，最敏感的参数是植被覆盖度和土壤粘聚力，而对于细沟流，这些是粘聚力和坡度。在这两种情况下，细沟网络信息作为模型的输入对模拟结果的影响很小。
Hillslope erosion causes important soil loss, contributes significantly to contaminant transport, and causes stream and lake embankment. Recent studies estimate that worldwide, the existing 45,000 dams (dams over 15 m [49 ft] high) trap more than 25% of global sediment flux and that these dams would be losing between 0.5% and 1% of their capacity annually (Syvitski et al. 2005). Additionally, the increase in soil erosion due to human mismanagement causes advancing desertification of the landscape. The aim of this work is to provide an alternative tool for decision making regarding erosion management in the Chilean “Secano” (dryland) area. Specifically, a numerical erosion model with a physical base was developed and tested. Although the model is based on previous developments, it considers rainfall splash together with sheet and rill flow in a novel way and can be easily incorporated in distributed hydrological models and/or geographical information systems. It is an event model, which divides the hillslope length into elements. Water and sediment can enter each element from upslope, while Manning's equation is used to estimate mean velocities. New data gathered in the area, the first to be obtained in a systematic manner, was available from field plots in the Secano and was used to test the model. Soil loss had been monitored for a year in standard erosion plots with three different treatments: traditional rotation (wheat/fallow), no-till rotation (wheat/legume), and natural prairie (plus one bare soil control per slope). The total event sediment loss for the treatments was predicted rather well without using parameter calibration, obtaining estimations within 35% to 165% of field measurements and reasonable root-mean square errors, given the range expected when models were applied to data from plots installed in agricultural fields. Two-way analysis of variance results suggest the model considers factors of slope and treatment well, and the results show an overall r2 of 0.46 considering all pairs of estimated values to measurements. Predictions were better for the case of milder slopes and native vegetation (prairie). Sensitivity analysis showed that for sheet flow, the most sensitive parameters were vegetation cover and soil cohesion; while for rill flow, these were cohesion and slope. In both cases, the rill network information provided as input to the model had little effect on simulation results.