Erosion risk assessment of active coastal cliffs in temperate environments
Erosion risk assessment of active coastal cliffs in temperate environments
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DOI：
10.1016/j.geomorph.2009.05.009
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发表时间：
2009-11
期刊：
影响因子：
3.9
通讯作者：
L. Río;F. Gracia
中科院分区：
文献类型：
--
作者：
L. Río;F. Gracia
悬崖衰退造成的潜在负面后果是全世界许多沿海地区严重关切的问题。传统上，对这类过程的评估是通过计算平均悬崖衰退率并将其预测到未来来进行的，而没有考虑到影响悬崖动态和稳定性的各种因素。在这项工作中，提出了一种新的，实用的方法来评估悬崖侵蚀风险的温带环境，通过分析的主要因素负责的物理和社会经济方面的侵蚀，代表悬崖损失的潜力和损害的潜力分别。为此目的，提出了11个物理变量（如悬崖岩性，海滩特性或降雨状况）和6个社会经济变量（如土地利用类型或人口密度）的集成。这些变量被加权并组合成危害指数和影响指数，这反过来又被合并成一个综合风险指数，其中得到的值被归一化并表示为最大理论风险的百分比。该方法进行了测试和验证，使用的数据悬崖撤退率和质量运动过程中的海岸加的斯省（西南西班牙）。所提议的办法允许根据风险、危害和/或影响程度对沿海悬崖进行分区，包括确认应采取具体干预战略的关键地区。据认为，这项工作中提出的方法是实用的，同时在科学上是有效的，而不需要广泛和详细的调查，在该地区的应用。这样，它就构成了一个易于使用、有价值的工具，用于有关活跃沿海悬崖土地利用规划和管理策略的决策。
The potentially negative consequences resulting from cliff recession are a matter of serious concern in many coastal areas worldwide. The assessment of these kind of processes has traditionally been performed by calculating average cliff recession rates and projecting them into the future, without taking into consideration the diverse factors affecting cliff dynamics and stability. In this work a new, practical method is presented to evaluate cliff erosion risk on temperate environments, by analysing the main factors responsible for both the physical and the socioeconomic aspects of erosion, representing cliff loss potential and damage potential respectively. For this purpose an integration of 11 physical variables (such as cliff lithology, beach characteristics or rainfall regime) and 6 socioeconomic variables (such as land use type or population density) is proposed. These variables are weighted and combined into a Hazard Index and an Impact Index, which in turn are merged into a composite Risk Index, where the resulting values are normalized and expressed as a percentage of the maximum theoretical risk. The method is tested and validated by using data about cliff retreat rates and mass movement processes in the coast of Cádiz province (SW Spain). The proposed approach allows the zoning of coastal cliffs according to the risk, hazard and/or impact levels, including the recognition of critical areas where specific intervention strategies should be adopted. It is believed that the method presented in this work is practical and at the same time scientifically valid, without requiring extensive and detailed surveys of the area where it is to be applied. This way, it constitutes an easy to use, valuable tool for decision-making regarding land use planning and management strategies in active coastal cliffs.