In order to improve the safety supervision efficiency of urban gas pipeline network, we applied the synergetic entropy theory to establish a quantitative risk synergetic governance analysis framework. Firstly, five synergistic entities were analyzed from three aspects of government, enterprise and society, then 24 synergistic elements were identified. Secondly, the risk synergetic governance mode for safety production accidents of urban gas pipeline network was established. Thirdly, the “$6\cdot 13$” accident which happened in Shiyan City, Hubei Province was taken as a illustrative case, and the synergy degree of each entity was calculated. The conclusions prove that the government department is the objective key to safety management of urban gas pipeline network, the gas enterprises and the third-party units should actively cooperate with other entities through the construction and improvement of the market-oriented mechanisms, and the industry associations and academics should be devoted to provide technical support for other entities. All the entities should work together to improve the entire risk synergetic governance system.
Urban infrastructure is the basis for maintaining normal social and economic activities in a city. In recent years, infrastructure systems are increasingly interconnected in China, subsequently an interacted system in which infrastructures are closely related and interdependent is formed. In this paper, citespace is used to analyze the temporal and spatial distribution characteristics of relevant literatures, meanwhile, the knowledge map and the timeline map of keywords are constructed to identify research hotspots. Jaccard index and Salton index are adopted to measure the interdependencies between infrastructures composed by 7 traditional infrastructures together with 7 new infrastructures. The results show that cascading effect, interdependent network and complex system are the key areas of related research field, and Internet of Things/IoT-cloud computing, electricity/electric power-natural gas/fuel gas, electricity/electric power-communication/telecommunication are highly interdependent.
岩溶塌陷受多种因素影响,其发生具有突然性,分布具有空间分异性.为合理的对怀化地区岩溶塌陷进行易发性评价,采用地理探测器和随机森林模型对怀化地区开展岩溶塌陷易发性评价,分析了岩溶塌陷的主要影响因素和影响因素之间的相互作用,将Geodetector-IV-RF、IV-RF和IV模型的易发性评价结果进行对比分析.结果表明:岩溶发育程度、岩溶水位与基岩面关系和岩溶塌陷密度这3 个影响因素对岩溶塌陷的解释程度较高;岩溶塌陷影响因素两两之间相互作用类型为双因子增强或非线性增强,都对岩溶塌陷发生起增强作用;Geodetector-IV-RF模型的评价结果精度最高,分区结果可以为研究区岩溶塌陷的防治工作提供辅助预警作用.
为把握中国粮食市场供需形势,探究自然灾害对粮食产量冲击影响及内在机制,该文借助中国农业产业模型进行模拟分析.结果表明:①稻谷、小麦市场供需呈下滑态势,稻谷净进口增长,小麦净进口下滑;玉米供需总体保持增长,净进口维持在较高水平;粮食自给率总体高位运行,2035 年稻谷、小麦、玉米自给率分别达到99.05%、98.65%和92.34%.②自然灾害不利于粮食生产和消费,推动净进口增加;随着自然灾害不断增强,粮食市场所受影响加深,粮食自给率下降;水灾对粮食市场供需影响更大,旱灾影响相对较小;自然灾害成灾率每提高1 个百分点,稻谷、小麦和玉米自给率较基准水平下降0.16 个百分点、0.38 个百分点和0.33 个百分点.建议坚持以自给为主、夯实国内粮食供给保障基础,推动多元合作、巩固拓展国际粮食供应链,强化监测预警、持续提升粮食安全风险管控能力,多渠道打好组合拳,强化粮食安全韧性和应对自然灾害等风险挑战能力.
In recent years, with the continuous intensification of global climate change, extreme weather and disaster events have been occurring frequently in China, and the subsequent abnormal changes in land surface temperature（LST） have posed a huge threat to the stability of the climate environment and agricultural production.The surface temperature is an important reference index for measuring the earth’s environment, and it has an important impact on the regional climate change and energy cycle, the balance of the ecosystem, and the production and life of human beings.In this study, owing to the lack of pixel information and low accuracy in some areas of MODIS land surface temperature data due to cloud and rain weather, a higher-quality monthly-scale remote sensing land surface temperature dataset of China from 2002 to 2018 is reconstructed by constructing a data restoration model.The reconstructed LST data has an accuracy of about 1.5 K and covers more complete pixel information.Studies have proved that this method can effectively improve the lack of MODIS LST data and further improve the utilization of MODIS LST data.On this basis, the characteristics of the temporal and spatial changes of China’s surface temperature in different time dimensions are analyzed from multiple spatial scales such as the whole, local and single pixel, and special attention and research are carried out on areas with abnormal changes in surface temperature during 17 years.Finally, combined with a variety of data such as the surface, atmosphere, ocean, and social and economic activities, we deeply explored the driving factors of the temporal and spatial changes of my country’s surface temperature from 2002 to 2018,especially the inter-annual abnormal changes.
