Application of the SHETRAN basin‐scale, landslide sediment yield model to the Llobregat basin, Spanish Pyrenees
Application of the SHETRAN basin‐scale, landslide sediment yield model to the Llobregat basin, Spanish Pyrenees
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SHETRAN 盆地规模滑坡产沙量模型在西班牙比利牛斯山脉 Llobregat 盆地的应用
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发表时间：
2006
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通讯作者：
F. Gallart
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作者：
J. Bathurst;A. Burton;B. Clarke;F. Gallart
1982年11月，在西班牙比利牛斯山脉东部的略布列加特盆地上部505平方公里的一次重大滑坡事件中，首次应用了SHETRAN盆地尺度、滑坡侵蚀和产沙模型。该模型模拟了浅层滑坡的空间分布及其产沙量。考虑到模型参数评估中的不确定性，应用程序的目的不是通过一次模拟尽可能准确地再现观测到的滑坡发生情况，而是将观测到的模式与代表关键输入条件不确定性的几个模拟结合起来。因此，滑坡模拟的边界被确定为植被根系黏聚力（用于模型安全系数计算）的不确定性函数。由此产生的上限大大高估了观测到的模式（17000次滑坡，而观测到的滑坡约为700次），但它再现了观测到的模式中的几个主要集群。下限包含大约500个滑坡。产沙量估算值（2670 - 14630 t km−2）与比利牛斯山脉其他地方的极端事件测量值相当。结果表明，能够模拟流域尺度的滑坡对降雨事件的响应和由此产生的产沙量。他们还强调，需要进一步研究确定不确定性界限，并避免对滑坡发生的大规模高估，这在一定程度上是由于目前无法对给定规模的盆地进行小规模控制建模。版权所有©2006约翰威利父子有限公司
The first application of the SHETRAN basin‐scale, landslide erosion and sediment yield model is carried out for a major landsliding event in the upper 505 km2 of the Llobregat basin, in the eastern Spanish Pyrenees, in November 1982. The model simulates the spatial distribution of shallow landslides and their sediment yield. Acknowledging uncertainty in the model parameter evaluation, the aim of the application was not to reproduce the observed occurrence of landslides as accurately as possible with one simulation, but to bracket the observed pattern with several simulations representing uncertainty in the key input conditions. Bounds on the landslide simulations were thus determined as a function of uncertainty in the vegetation root cohesion (used in the model factor of safety calculations). The resulting upper bound considerably overestimates the observed pattern (17 000 landslides compared with an observation of around 700), but it reproduces several of the principal clusters in the observed pattern. The lower bound contains around 500 landslides. The sediment yield estimates (2670–14 630 t km−2) are comparable to measurements elsewhere in the Pyrenees for extreme events. The results demonstrate an ability to simulate the basin‐scale landslide response to a rainfall event and the resulting sediment yield. They also highlight the need for further research in setting the uncertainty bounds and in avoiding large overestimates of landslide occurrence arising in part from a current inability to model small‐scale controls for a basin of the given size. Copyright © 2006 John Wiley & Sons, Ltd.