Surface Runoff Generation and Soil Loss Under Different Soil and Rainfall Properties in The Uluguru Mountains, Tanzania
Surface Runoff Generation and Soil Loss Under Different Soil and Rainfall Properties in The Uluguru Mountains, Tanzania
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DOI：
10.1002/ldr.2499
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发表时间：
2017-01
影响因子：
4.7
通讯作者：
T. Nishigaki;S. Sugihara;M. Kilasara;Shinya Funakawa
中科院分区：
文献类型：
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作者：
T. Nishigaki;S. Sugihara;M. Kilasara;Shinya Funakawa
水蚀是造成世界各地山区土地退化的主要问题之一，其特点因不同地点的土壤和气候条件而有很大变化。为了研究土壤和降雨特性对地表径流和土壤流失的影响，我们在坦桑尼亚乌卢古鲁山区的4个地点（NY、TA、SO和MA）安装了用波纹铁皮围成的径流小区（宽0.8 m ×坡长2.4 m），并评估了每个雨季降雨事件的降雨、地表径流和土壤水分的水量收支。两个站点，纽约和TA，位于山区，有陡峭的斜坡和较高的降雨量，而两个山麓站点，SO和MA，平坦，粗糙的纹理。径流量与降雨量有关，但也与入渗能力有关。在地表层、TA和MA渗透性较高的站点，山区径流量高于山麓站点，而径流率较低。山区降雨量大、强度大，基本上会增加泥沙含量和土壤流失量。土壤质地也控制土壤的可蚀性; MA的土壤流失量是SO的两倍，由于桑迪土壤，尽管MA和SO的降雨量相似。结果表明，山区降雨量大，桑迪土壤对侵蚀的敏感性高，加剧了水蚀造成的土壤流失。版权所有© 2016约翰威利父子有限公司.
Water erosion is one of the main concerns driving land degradation in mountainous areas throughout the world, and its characteristics change widely with soil and climate conditions in different locations. To investigate the effects of soil and rainfall properties on surface runoff and soil loss, we installed runoff plots (width 0·8 m × slope length 2·4 m) enclosed by corrugated iron sheets, and evaluated water budgets for rainfall, surface runoff and soil moisture for every rainfall event over a rainy season at four sites (designated NY, TA, SO and MA) in the Uluguru Mountains of Tanzania. Two of the sites, NY and TA, were located in mountainous areas and had steep slopes and higher rainfall amounts, while the two foothill sites, SO and MA, were flatter and with coarser textures. Runoff amount was related to rainfall amount, but also to infiltration capacity. Runoff amounts in mountainous areas were higher than in foothill sites while runoff ratio was low at sites with high permeability in the surface layer, TA and MA. Sediment concentrations and soil loss were basically enhanced by high rainfall amount and intensity at mountainous sites. Soil texture also controlled the erodibility of soils; MA had twice the soil loss of SO owing to sandy soil despite similar rainfall amounts at MA and SO. Our results show that the high rainfall amounts in the mountainous areas and high susceptibility of sandy soils to erosion enhanced soil loss by water erosion in this study. Copyright © 2016 John Wiley & Sons, Ltd.