基于环境污染型企业的中国城市网络空间结构研究

城市网络的环境效应是当前城市网络研究中相对较被忽视的研究议题。通过对2001年和2020年环境污染型上市企业数据的收集和分析，揭示基于环境污染型企业的中国城市网络总体演化格局，在此基础上进一步探索城市之间通过污染型机构-非污染型机构联系而产生的污染转移网络空间特征。结果表明：(1)基于环境污染型企业的中国城市网络总体呈现出从东部发达地区向中西部欠发达地区不断扩张的趋势，网络分层结构日趋明显，不同层级城市网络在地理空间上表现出一定的异质性。(2)环境污染型企业城市网络具有典型的“核心-边缘”结构，高位序节点城市数量相对稳定，中低位序节点城市数量增长较快，各城市组团分布呈现出日益明显的地域性集聚特征。(3)企业污染转移网络同样呈现出不断扩张的态势和日益明显的层级结构，跨省转移成为城市网络污染转移的主导模式，行政边界效应并不明显。(4)城市网络污染转移空间指向性明显，主要表现为沿海发达城市向内地工业型城市、区域中心城市向周边城市以及同类资源型城市之间的空间转移，反映出城市经济制度差异等因素对城市网络环境污染转移的影响。研究结果对于环境污染型企业的空间治理提供了重要的启示。

The spatial structure of the urban network of environmentally polluting enterprises in China

Urban network has become a focus of analysis in geography, urban studies and other related disciplines. However, the environmental effect of urban networks is a relatively neglected topic in the current research on urban networks. By collecting and analyzing the data of listed environmentally polluting enterprises in 2001 and 2020, this paper reveals the structure of the urban network of China′s environmentally polluting enterprises using the method of social network analysis. It further explores the spatial characteristics of the inter-city network of pollution transfer generated through the connections between polluting and non-polluting affiliates of these enterprises. The results show that: (1) the urban network of environmentally polluting enterprises has exhibited a trend of expansion from the eastern developed regions to the underdeveloped regions in central and western China. An increasingly clear hierarchical structure of the urban network can be identified, with different levels of the network showing a certain degree of heterogeneity in terms of geographic pattern. (2) The urban network of environmentally polluting enterprises displays a typical "core-periphery" structure. The number of high-ranking nodal cities is relatively stable, whereas that of middle- and low-ranking cities is growing rapidly. The distribution of cities in different clusters shows an increasingly obvious pattern of regional agglomeration. (3) The pollution transfer network of enterprises exhibits a similar pattern of continuous expansion and an increasingly obvious hierarchical structure. Inter-provincial transfer becomes the dominant model of pollution transfer, whereas the impact of administrative boundary is not significant. (4) The transfer of pollution within the urban network demonstrates an obvious spatial directivity, which is mainly transferring from the economically advanced coastal cities to the inland industrial cities, from the regionally central cities to their surrounding small- and medium-sized cities, and between similar resource-based cities. The spatial pattern of pollution transfer within the urban network reflects the impacts of urban economic development, industrial structure, resource condition and inter-regional institutional disparity. This study enriches the theoretical and empirical understanding of the environmental effects of urban networks. The results also offer some valuable references for the spatial governance of environmentally polluting enterprises.