基于GIS和熵权法的滑坡作用下的长输油气管道易损性评价

Vulnerability Evaluation of Long-Distance Oil and Gas Pipelines under Landslide Actions Based on GIS and Entropy Weight Method

开展滑坡作用下的长输油气管道易损性评价,对于管道建设中的决策制定及防灾减灾具有重要意义。以兰州—成都—重庆(兰成渝)输油管道广元段实地调查测量数据为依托,从管道与滑坡空间关系、管道本体两方面出发,选取管道缺陷密度、管道壁厚、管道埋深、管道与斜坡单元夹角、管道位置等9个评价指标,基于ArcGIS、MATLAB软件平台和熵权赋值理论,进行管道易损性定量评价,并提出相应的管理建议。研究结果表明:(1)管道缺陷密度、管道壁厚、管道与斜坡单元夹角的熵权值分别为0.679、0.154、0.102,是对管道易损性影响最大的三个因子;(2)低易损性、中易损性、高易损性和极高易损性的管段数量占比分别为66.66%、20.56%、12.22%、0.56%,长度占比分别为62.06%、25.72%、12.11%、0.11%;(3)研究区北部的管道易损性等级较低,南部的易损性等级较高,高和极高易损性管道主要分布于下寺镇及宝轮镇。评价结果较好地反映了研究区内管道易损度现状,可为研究区管道管理及其他类似区域管道线路规划提供可靠参考。

Landslides are one of the most popular geohazards threatening pipeline engineering in China.For the purpose of decision-making and geohazard prevention and control in pipeline construction,it is of great significance to evaluate the vulnerability of long-distance oil and gas pipelines subjected to landslides.In this research,it conducted field survey on geohazards along the Guangyuan section of the Lanzhou-Chengdu-Chongqing(Lan-Cheng-Yu)oil pipeline.In terms of the spatial relationship between pipelines and landslides,and the physical properties of pipelines,9 evaluation indexes including pipeline defect density,pipe wall thickness,buried depth of pipeline,the angle between pipeline and slope,pipeline position,etc.were selected to make an quantitative evaluation on pipeline vulnerability and grade division based on ArcGIS,MATLAB software platform and entropy weight theory;therefore it proposed the corresponding management strategy.The results showed that:(1)the values of entropy weights for pipeline defect density,pipe wall thickness and the angle between pipeline and slope were 0.679,0.154 and 0.102 respectively;All of the three indexes had the greatest influence on pipeline vulnerability;(2)The pipeline sections with low,medium,high and very high vulnerability accounted for 66.66%,20.56%,12.22%and 0.56%,respectively;Accordingly the length accounted for 62.06%,25.72%,12.11%and 0.11%,respectively;(3)The pipeline vulnerability level in the north of the study area was low,but in the south was high.The pipelines with high and very high vulnerability were mainly distributed in Xiasi Town and Baolun Town.In view of this part of the pipeline,we recommend that increase the prevention and control engineering,carry out the real time monitoring,and achieve timely maintenance.The evaluation results fairly match with current reality of pipeline vulnerability in the study area,and can provide a reliable reference for pipeline management in the study area and pipeline route planning in other similar areas.