Analysis of topographic and climatic control on rainfall-triggered shallow landsliding using a quasi-dynamic wetness index
Analysis of topographic and climatic control on rainfall-triggered shallow landsliding using a quasi-dynamic wetness index
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DOI：
10.1016/s0022-1694(02)00118-x
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发表时间：
2002-11-01
影响因子：
6.4
通讯作者：
Cazorzi, F
中科院分区：
文献类型：
--
作者：
Borga, M;Fontana, GD;Cazorzi, F
提出了一种地形和气候对丘陵山地浅层滑坡起爆过程控制的预测模型。该模型是在Montgomery和Dietrich[水资源]先前提出的浅层地下流动和土壤地幔滑坡耦合理论的基础上发展起来的。该模型使用“准动态”湿度指数来预测土壤饱和度响应特定持续时间降雨的空间分布。预计在每个地形要素中引起不稳定的降雨的特征是持续时间和发生频率。将降雨频率-持续时间关系纳入滑坡危害评估提供了一种将气候信息纳入浅层滑坡相对潜力评估的实用方法。该模型应用于一个山区实验盆地，那里有高分辨率数字高程数据：意大利东北部的Cordon集水区（5公里(2)）。滑坡疤痕的清单用于记录不稳定的地点，并通过比较观察到的滑坡位置与模型预测提供模型性能的测试。该模型合理地再现了观测到的滑坡分布，尽管该模型没有考虑土壤性质的空间变异性和水文复杂性，这使得在类似的地形-气候控制区域内滑坡发生的预测复杂化。准动态模型的预测结果与稳态模型的预测结果进行了比较[Water resource， Res. 30(1994) 1153]，这些结果表明，准动态模型在预测考虑的滑坡清单中所代表的现有滑坡方面，比稳态模型有了显著的改进。(C) 2002年Elsevier Science B.V.出版
A model for the prediction of both topographic and climatic control on shallow landslide initiation processes in hilly mountainous terrain is proposed. The model develops upon a theory for coupled shallow subsurface flow and landsliding of the soil mantle previously proposed by Montgomery and Dietrich [Water Resour. Res, 30 (1994) 1153], The model uses a 'quasi-dynamic' wetness index to predict the spatial distribution of soil saturation in response to a rainfall of specified duration. The rainfall predicted to cause instability in each topographic element is characterised by duration and frequency of occurrence. The incorporation of a rainfall frequency-duration relationship into assessment of landslide hazard provides a practical way to include climate information into estimation of the relative potential for shallow landsliding. The model is applied to a mountain experimental basin where high-resolution digital elevation data are available: the Cordon catchment (5 km(2)), in north-eastern Italy. An inventory of landslide scars is used to document sites of instability and to provide a test of model performance by comparing observed landslide locations with model predictions. The model reasonably reproduces the observed distribution of landslides, although spatial variability of soil properties and hydrologic complexities not accounted for by the model complicate prediction of where landslides occur within areas of similar topographic-climatic control. Model predictions from the quasi-dynamic model are compared with those provided by the steady-state model [Water Resour, Res. 30 (1994) 1153], These results suggest that the quasi-dynamic model offers significant improvement over the steady-state model in predicting existing landslides as represented in the considered landslide inventory. (C) 2002 Published by Elsevier Science B.V.