杨金顺
现有的公路交通系统主要从区域经济发展的角度开展布局规划，很少考虑所经地区的气候气象条件，造成公路交通系统本身存在难以应对气象灾害及次生灾害的先天不足。在我国公路规模不断扩大，同时因气候变化造成气象灾害愈发严重的情况下，这一不足越来越突出，从而制约了区域社会经济的发展，并给公路交通安全带来巨大威胁。因此，有必要针对变化的气候条件，对现有公路的规划设计理念、方法、内容等问题进行重新审视和考量，在研究气候变化的基础上，建立适应气候变化的公路网规划体系，以提高公路网自身应对气象灾害的能力，减少气候变化对公路交通造成的影响。
首先，总结梳理了气候变化与公路交通交叉领域的相关研究与应用成果，主要包括气候变化领域、公路规划领域、交通系统灾害领域及公路应急救援领域的研究成果。对气候变化的史实与趋势、气候变化带来的影响与策略、公路规划历程与发展方向进行了分析，特别对交通灾害领域的风险研究、交通气象安全研究、恢复力研究、脆弱性研究及应急救援进行了重点梳理，通过对这些成果的综述研究，寻找适应气候变化的公路网规划研究的切入点与研究重点。
第二，分析了气候变化对公路交通的影响。研究影响公路交通的气候变化因素以及特点。重点分析了因气候变化导致的频发气象灾害对公路交通的影响机理，这些气象灾害包括极端降水、冰雪、雾、极端温度（极端高温、极端低温）、大风、沙尘暴，以及由气象灾害导致的次生地质灾害（滑坡、崩塌、泥石流等）。同时梳理了现有公路网规划体系中的气象气候要素，总结了我国公路与气象交叉领域的相关规范，针对在公路网规划阶段如何考虑气象气候要素提出了相关建议，为保证在公路网规划层面对相关问题做全面考虑，构建切实有效的公路网规划理论与方法体系提供依据。
第三，从主动适应气象气候灾害的角度，研究了公路网生命线规划方法。基于交通恢复力理论，提出了公路网生命线的基本概念，并阐述了规划的原则与思路，构建了公路网生命线规划理论与方法体系。研究了公路网气候气象特征，重点对公路网气象灾害危险性进行分析，并以此为基础进行节点规划和线路规划，完成公路网生命线的布局规划。公路网气象灾害危险性分析包括危险性指标的选取、评价体系与方法的构建、评价等级的划分等，危险性分析是生命线规划的重要依据，基于单灾种及综合灾害的危险性评价值，计算得到公路网的节点气象灾害危险性评价值和路段危险度，进而进行生命线的节点选择和路线选择，以构建适应气候变化的公路网生命线规划方法。
第四，从被动适应气象气候灾害的角度，研究了公路网应急救援点规划方法。针对因气候变化造成的气象灾害问题，对公路网应急救援点的功能要求、选址影响因素等救援点特征进行了分析，并根据公路网应急救援点的自身特点，对选址规划的顾客、设施、空间、度量等基本要素进行了研究。在此分析基础上建立了多目标决策的选址优化模型，主要从公路气象灾害应急救援的时间紧迫性要求、建设成本最小、灾害损失最小为目标进行选址优化，并对提出的选址模型求解算法进行研究，应用数值计算软件辅助实现模型的求解，以提高公路网应急救援点选址决策的实用性和高效性。
第五，研究了公路网规划的气象灾害风险评价方法。构建了公路网规划的气象灾害风险评价体系，将风险评价的内容划分为致灾因子的危险性评价和公路网脆弱性评价两个主要部分，公路网脆弱性评价又包括物理暴露性、灾害损失敏感性和抗灾能力评价，选取层次分析法和模糊综合评价法进行风险评价。对公路网脆弱性的评价指标选取、评价步骤进行了研究，并基于危险性评价和脆弱性评价进行风险等级的划分与风险区划研究。
最后，以杭州市公路网为例对提出的公路网规划理论与方法进行了实例应用。结合杭州地区的公路网情况，对公路网现状、区域气候特征及地质条件、主要气象灾害及次生灾害、公路历史灾害等基础资料进行了收集分析。在此基础上，进行了杭州市公路网生命线规划、桐庐县公路网应急救援点规划及桐庐县公路网气象灾害风险评价，对提出的适应气候变化的公路网理论与方法进行了实践应用。
关键词：公路网，气候变化，气象灾害，生命线规划，应急救援点，选址规划，风险评价，灾害危险性，脆弱性，交通恢复力
The present planning of highway transportation system mainly considers regional economic development, and rarely thinks over climate weather conditions. So the highway transportation system is difficult to cope with meteorological disasters and secondary disasters. With China's highway expanding, meanwhile more severe meteorological disasters caused by climate change, the deficiency is becoming more and more visible. Therefore, it is necessary to re-examine and consider the existing highway planning concepts, methods, content and other issues according to the changing climatic conditions. The highway network planning system should be established on the basis of climate change research, to improve the ability against the weather disasters and reduce the impact of climate change.
Firstly, the research and application results in the cross field of climate change and highway transportation were summarized. These fields mainly include climate change, highway planning, transportation disasters systems and highway emergency rescue. The climate change facts and trends, the impact and strategies of climate change, the planning course and development direction of highway network were analyzed. The research results such as transportation disasters risks, traffic meteorology safety, resilience, vulnerability and emergency rescue were reviewed, in order to seek the starting point and focus of highway network planning research adaptation to climate change.
Secondly, the impacts of climate change on highway transportation were analyzed. The factors and characteristics of climate change affecting highway transportation were studied. The affecting mechanisms of frequent meteorological disasters by climate change on highway transportation were analyzed. These meteorological disasters include extreme precipitation, snow, fog, extreme temperatures (extreme heat, extreme cold), high winds, dust storms, and secondary geological disasters caused by meteorological disasters (landslides, collapses, landslides, etc.). The meteorological climate elements in the existing highway network planning system were analyzed. The relevant standards and criterions of the existing highway and meteorological fields were summarized. The suggestions considering meteorological climate factors in the highway network planning stage were proposed, to provide the basis of building effective highway network planning theory and methodology system.
Thirdly, the highway lifeline planning method was studied from the aspect of active adaptation to meteorological and climatic disasters. Based on the theory of traffic resilience, the basic concept of the highway lifeline planning was proposed. The planning principles and processes were studied. The highway lifeline planning theory and methodology system was built. The climatic and meteorological characteristics of highway network were firstly studied, and the focus of study was to analyze highway meteorological disasters hazard. Then study the node planning, route planning and network planning of highway lifeline. The highway meteorological disasters hazard analysis include selecting risk indices, constructing the evaluation system and methods, evaluation grade division, etc. The disasters hazard analysis is an important basis for planning lifeline. Based on the hazard evaluation value of single disaster or multi-disasters, calculated the highway node meteorological disasters hazard evaluation value and highway sections hazard evaluation. And then select the highway lifeline node and route, build the highway lifeline network.
Fourthly, the location planning method of highway emergency rescue site was studied from the aspect of passive adaptation to meteorological and climatic disasters. For meteorological disasters caused by climate change, the features of emergency rescue site including functional requirements and location factors were analyzed. According to the characteristics of highway emergency rescue site, the basic elements were analyzed from four aspects including customers, facilities, space and measurement. A multi-objective optimization location model of highway emergency rescue site was built on the above analysis. The optimal objectives of location planning were the request of time urgency, minimizing construction costs and minimizing disaster losses. The solution algorithm of the location model was studied. The Lingo numerical solution software was applied to solve the optimization model, in order to improve the location decisions of highway emergency rescue site practicality and efficiency.
Fifthly, the meteorological disasters risk evaluation method of highway network planning was studied. The meteorological disasters risk evaluation system was built. The risk evaluation contents were divided in two main parts. One was hazard evaluation of disaster-causing factors, and another was vulnerability evaluation of highway network. The highway network vulnerability evaluation included physical exposure, disaster losses sensitivity and capability against disaster. The AHP and fuzzy comprehensive evaluation method were selected to assess the meteorological disasters risk. The highway network vulnerability evaluation indices and evaluation steps were studied. In addition, the risk grading and risk zonation were studied based on risk evaluation.
Finally, a case study of the proposed highway network planning theories and methods was applied to the Hangzhou highway. According to the situation of Hangzhou highway network, the basic information such as highway infrastructure, regional climate characteristics, geological conditions, the main meteorological disasters and secondary disasters, highway historical disasters were collected and analyzed. The Hangzhou highway lifeline planning, Tonglu highway network emergency rescue site location planning and Tonglu highway network meteorological disasters risk evaluation were studied successively.
Key Words: highway network, climate change, meteorological disasters, lifeline planning, emergency rescue site, location planning, risk evaluation, disasters hazard, vulnerability, traffic resilience
