西藏亚东县道路连通性及其受地质灾害的影响

开展西藏自治区亚东县道路连通性及其受地质灾害的影响研究，对改善当地路网连通性、提高山地灾害紧急疏散能力具有重要意义.利用遥感高清影像，采取目视解译结合实地考察的方式，获取亚东县道路和地质灾害数据；利用模糊层次法评估道路综合性能，构建道路连通性模型和地质灾害指数模型，探讨地质灾害对道路连通性的影响.结果表明：(1)亚东县地质灾害点有29个，主要集中分布在县域西南部区域，以崩塌为主.(2)路网具有典型树状特征，综合性能较好，但空间发育不均衡.(3)道路全局连通性呈现出“三核、两轴、一圈”的空间格局；局部连通性的空间差异较大，形成了4个局部高值区；中心连通性圈层结构明显，从中心向边缘的距离衰减特征明显.(4)亚东县地质灾害对居民点至各乡（镇）道路连通性的影响最大，对居民点至县政府道路连通性的影响次之，对居民点至最邻近的乡（镇）道路连通性的影响最小.

Road connectivity and its response to geological hazards in Yadong County,Tibet

Research on the road connectivity and its response to geological hazards in Yadong County, Tibet, is of great significance to improve the regional connectivity of road networks and enhance the emergency evacuation capacity to mountain hazards. In this paper, the road and geohazard data of Yadong County are obtained from the high-definition remote sensing images and field work. And then the comprehensive performance of the roads in Yadong County is assessed by using the fuzzy hierarchy method. Furthermore, a road connectivity model and a geohazard index model are constructed to explore the influence of geohazards on road connectivity. The results show that: ① Twenty-nine geological hazards sites are found in Yadong County and they are distributed mainly in the southwestern region of the county, most of which are collapse sites. ② The road network of Yadong County demonstrates typical tree-like network characteristics, with good comprehensive performance but uneven spatial development. ③ The global connectivity of the road network shows a spatial pattern of “three cores, two axes and one circle”: the specific connectivity among different regions displays obvious spatial differences with four high value areas; while the central connectivity demonstrates a clear circular structure and significant distance decay distribution. ④ The geological hazards in Yadong County have the greatest impacts on the road connectivity from the settlements to the townships, followed by the impacts on the road connectivity from the settlements to the county government, and the road connectivity from the settlements to the nearest townships.