Combination of statistical and physically based methods to assess shallow slide susceptibility at the basin scale
Combination of statistical and physically based methods to assess shallow slide susceptibility at the basin scale
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DOI：
10.5194/nhess-17-1091-2017
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发表时间：
2017-07
影响因子：
4.6
通讯作者：
S. Oliveira;J. Zêzere;Sara Lajas;Raquel Melo
中科院分区：
文献类型：
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作者：
S. Oliveira;J. Zêzere;Sara Lajas;Raquel Melo
抽象的。在盆地尺度上用于评估浅层滑坡敏感性的方法在概念上是不同的，这取决于统计方法或物理方法的使用。前者基于这样的假设，即相同的原因更有可能产生相同的结果，而后者则基于倾向于促进沿斜坡运动的力与阻碍运动的反作用力之间的比较。在这一总体框架内，这项工作检验了两个假设：(I)尽管在概念和方法上是不同的，但关于模型的预测能力和空间一致性，统计方法和确定性方法产生了类似的浅层滑坡敏感性结果；(Ii)对于同一研究区域，用统计方法和物理方法获得的浅层滑坡敏感性图相结合，产生了更可靠的浅层滑坡敏感性模型。这些假设在葡萄牙里斯本北部的一个小试验场(13.9平方公里)用统计方法(信息值法，IV)和基于物理的方法(无限斜率法，IS)进行了检验。将统计方法和确定性方法生成的滑坡易感性图组合成新的滑坡易感性图。后者以一套综合规则为基础，这套综合规则是由两个图的易感类别的交叉制表和相应的联想表分析确定的。结果表明，新的浅层滑动磁化率图具有更高的预测能力，它将独立的结果与统计和物理模型相结合。此外，这两个模型的结合允许识别信息值方法和无限斜率方法的结果相互矛盾的区域。因此，这些地区被归类为不确定地区，需要进行更详细的进一步调查。
Abstract. Approaches used to assess shallow slide susceptibility at the basin scale are conceptually different depending on the use of statistical or physically based methods. The former are based on the assumption that the same causes are more likely to produce the same effects, whereas the latter are based on the comparison between forces which tend to promote movement along the slope and the counteracting forces that are resistant to motion. Within this general framework, this work tests two hypotheses: (i) although conceptually and methodologically distinct, the statistical and deterministic methods generate similar shallow slide susceptibility results regarding the model's predictive capacity and spatial agreement; and (ii) the combination of shallow slide susceptibility maps obtained with statistical and physically based methods, for the same study area, generate a more reliable susceptibility model for shallow slide occurrence. These hypotheses were tested at a small test site (13.9 km2) located north of Lisbon (Portugal), using a statistical method (the information value method, IV) and a physically based method (the infinite slope method, IS). The landslide susceptibility maps produced with the statistical and deterministic methods were combined into a new landslide susceptibility map. The latter was based on a set of integration rules defined by the cross tabulation of the susceptibility classes of both maps and analysis of the corresponding contingency tables. The results demonstrate a higher predictive capacity of the new shallow slide susceptibility map, which combines the independent results obtained with statistical and physically based models. Moreover, the combination of the two models allowed the identification of areas where the results of the information value and the infinite slope methods are contradictory. Thus, these areas were classified as uncertain and deserve additional investigation at a more detailed scale.