Risk Assessment of Land Subsidence in Kathmandu Valley, Nepal, Using Remote Sensing and GIS
Risk Assessment of Land Subsidence in Kathmandu Valley, Nepal, Using Remote Sensing and GIS
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DOI：
10.4236/ars.2017.62010
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
Richa Bhattarai;A. Kondoh
中科院分区：
文献类型：
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作者：
Richa Bhattarai;A. Kondoh
地面沉降被确定为一个全球性问题，世界各地正在进行深入研究，以检测和监测这一问题的风险。地面沉降风险评价是对地面沉降发生的概率和频率、地面沉降对人员和财产的影响以及地面沉降的后果进行评价。利用遥感技术提取尼泊尔加德满都谷地地面沉降信息。此外，灾害风险指数法和层次分析法（AHP）沿着与地理信息系统（GIS）工具，以评估地面沉降的风险在加德满都谷，尼泊尔。使用简单的数学公式计算了加德满都中部、Chauni、Lalitpur、Imadol、Thimi、Madhyaour Thimi、New Baneshwor、Koteshwor和Gothatar等地点的沉降量。发现这些位置的沉降深度在1 cm至17 cm的范围内，最大沉降速度为4.8 cm/年。这项研究表明，观察到最大沉降的位置（即加德满都中部和Lalitpur）被认为是经历地面沉降引起的损害的高风险。根据当前的数据情况，发现观察到沉降的其他位置处于中等风险，发现加德满都山谷的其余部分处于低风险。这项研究可以被认为是其他与地面沉降风险评估有关的综合研究的第一步。这项研究的结果提供了一个基本的了解目前的情况，可以进一步帮助开发预防和风险管理技术。
Land subsidence is identified as a global problem and intensive studies are being conducted worldwide to detect and monitor risk of this problem. Risk assessment of land subsidence is simply an evaluation of the probability and frequency of occurrence of land subsidence, exposure of people and property to the subsidence and consequence of that exposure. Remote sensing technology was used to extract information of land subsidence in Kathmandu Valley, Nepal. Also, Disaster Risk Index method and Analytic Hierarchy Process (AHP) along with Geographic Information System (GIS) tools were used to assess risk of land subsidence in Kathmandu Valley, Nepal. Subsidence volume for locations Central Kathmandu, Chauni, Lalitpur, Imadol, Thimi, Madhyaour Thimi, New Baneshwor, Koteshwor and Gothatar was calculated using a simple mathematical formula. The subsidence depth for these locations was found to be in a range of 1 cm to 17 cm and the maximum subsidence velocity was found to be 4.8 cm/yr. This study revealed that the location where maximum subsidence was observed (i.e. Central Kathmandu and Lalitpur) was found to be at high risk of experiencing land subsidence induced damage. Other location where subsidence was observed was found to be at medium risk and the rest of the Kathmandu valley was found to be at low risk with current data situation. This study can be considered as the first step towards other comprehensive study relating to land subsidence risk assessment. The outcome of this research provides a basic understanding of the current situation that can further assist in developing prevention and risk management techniques.