京津冀城市群人-地、人-水与人-碳交互胁迫关系及其叠加效应

随着社会、经济效益的不断增加及国际影响力的不断增大，京津冀正在向世界级城市群迈进。而快速的城市增长与资源环境的交互胁迫效应严重制约了京津冀地区的可持续发展，因此，明确城市增长与不同资源环境要素的相互作用机制并采用有效的措施，是实现京津冀地区发展和保护共生的关键。目前针对城镇化与单一种资源环境要素交互作用的研究较多，但对城镇化与不同资源环境要素相互作用的叠加效应的关注很少。针对土地、水资源与能源这三种明显限制京津冀地区发展的资源要素，综合考虑了供给侧与需求侧特征，分析了人-地、人-水与人-碳的相互作用关系，解析了京津冀地区城镇发展与不同资源环境要素交互胁迫作用及其叠加效应。结果表明：2002-2017年，1、城市群整体水平上，人-地、人-水和人-碳关系总体上均呈"强协调"或"弱协调"交替变化的状态；2、城市尺度上，不同城市的人-地、人-水和人-碳交互关系存在明显时空分异。多数城市都曾面临土地、水资源或能源的胁迫影响，尤其是河北的一些城市（石家庄、邯郸、承德、衡水、邢台、唐山及保定等）在有些年份面临土地、水资源或能源的"强胁迫"影响；3、从京津冀地区整体水平上看，不存在多种资源要素的叠加胁迫影响，但是，城市群内部多数城市在有的年份同时面临土地、水资源或能源两种以上资源要素的叠加胁迫影响。因此，要协同改善京津冀地区资源环境的胁迫，需要全面考虑不同空间尺度之间，不同城市之间，以及不同资源要素之间的叠加影响机制，有针对性的提出政策与措施。

Interactions between urbanization, land, water and carbon and their combined effects on Beijing-Tianjin-Hebei urban agglomeration

As one of the most important fast developed regions, the Beijing-Tianjin-Hebei (BTH) urban agglomeration plays an important role in global development due to its great socio-economic benefits. However, the dramatically fast development causes series of resources and environments problems including serious shortage of resources. Despite broad studies exploring the impacts of urbanization on some particular resources, little is known about the simultaneously combined effects of urbanization on different resources. In this paper, we took the BTH urban agglomeration as a pilot study and simultaneously explored the combined impacts of urbanization on land, water and energy. First, we developed a dynamic index to quantify the interaction between urbanization and resource from the view of resource supply and demand. Second, we investigated the combined impacts of urbanization on different resources. We found that (1) on aggregate level, the interactions between urbanization of the whole BTH and land, water and energy were all mainly "strong concordant" and "weak concordant"; (2) on city level, the interactions between urbanization and land, water and energy varied between different cities, and most cities faced the alternation occurrence of "weak stressed", "strong stressed", "weak concordant" and "strong concordant". Particularly in some cities (Shijiazhuang, Handan, Chengde, Hengshui, Xingtai, Tangshan, and Baoding) in Hebei province, they ever faced "strong stressed" interaction in some years; (3) the combined stressed effects by land, water or energy were found at city level, and most cities within the BTH were stressed by more than one resource in some years. Our findings highlight that it is imperative to comprehensively evaluate the interactions between urbanization and resources from different spatial scales and the nexus of different resources for decision-makers.