Spatial Landslide Risk Assessment at Phuentsholing, Bhutan
Spatial Landslide Risk Assessment at Phuentsholing, Bhutan
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DOI：
10.3390/geosciences10040131
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发表时间：
2020-04-01
期刊：
影响因子：
2.7
通讯作者：
Alamri, Abdullah M.
中科院分区：
文献类型：
--
作者：
Dikshit, Abhirup;Sarkar, Raju;Alamri, Abdullah M.
山体滑坡是喜马拉雅地区最具破坏性和最频繁发生的自然灾害之一。它们的发生会对基础设施造成巨大破坏，并造成土地、生命和牲畜的损失。受影响最严重的地区之一是不丹喜马拉雅山脉，那里的大多数山体滑坡都是由降雨引起的。本研究旨在确定位于不丹喜马拉雅山脉西南部的Phuentsholing地区与降雨引起的山体滑坡相关的危害和风险。这项工作包括利用2004年至2014年的滑坡记录绘制滑坡风险图和脆弱性图。通过确定研究区域的时空概率，生成滑坡灾害图。通过对滑坡的地质、坡度、高程、降雨、植被等影响因素的综合实地考察和专家分析，计算出滑坡的空间概率。将影响滑坡的因素分为不同的类别，并计算每一类下滑坡发生的百分比，以了解其影响程度。然后，在GIS环境下使用加权线性组合方法，将空间概率图与基于区域降雨阈值的时间概率相乘。因此，利用关键风险要素（人口、土地利用/土地覆盖、靠近道路、靠近河流）进行脆弱性评估，并根据专家判断和综合实地研究得出权重。最后，确定了风险，并将研究区域的各个区域划分为高、中、低风险。这样的研究对于像不丹这样缺乏广泛数据和研究的低经济国家是必要的。这项研究是针对一个特定地区进行的，但可以扩展到被调查地区周围的其他地区。该工具可作为民政当局分析该地区基础设施快速发展所带来的滑坡风险的指标。
Landslides are one of the most destructive and most recurring natural calamities in the Himalayan region. Their occurrence leads to immense damage to infrastructure and loss of land, human lives, and livestock. One of the most affected regions is the Bhutan Himalayas, where the majority of the landslides are rainfall-induced. The present study aims to determine the hazard and risk associated with rainfall-induced landslides for the Phuentsholing region located in the southwestern part of the Bhutan Himalayas. The work involves developing a landslide risk map using hazard and vulnerability maps utilizing landslide records from 2004 to 2014. The landslide hazard map was generated by determining spatial and temporal probabilities for the study region. The spatial probability was computed by analyzing the landslide contributing factors like geology, slope, elevation, rainfall, and vegetation based on comprehensive field study and expertise about the area. The contributing factors were divided into various classes and the percentage of landslide occurrence under each class was calculated to understand its contributing significance. Thereafter, a weighted linear combination approach was used in a GIS environment to develop the spatial probability map which was multiplied with temporal probabilities based on regional rainfall thresholds already determined for the region. Consequently, vulnerability assessment was conducted using key elements at risk (population, land use/land cover, proximity to road, proximity to stream) and the weights were provided based on expert judgment and comprehensive field study. Finally, risk was determined and the various regions in the study area were categorized as high, medium, and low risk. Such a study is necessary for low-economic countries like Bhutan which suffers from unavailability of extensive data and research. The study is conducted for a specific region but can be extended to other areas around the investigated area. The tool can serve as an indicator for the civil authorities to analyze the risk posed by landslides due to the rapid infrastructure development in the region.