City clusters in China: air and surface water pollution

growth over the past two decades, accompanied by the development of large-scale industries and services. In the course of this expansion, medium-sized cities and small towns have sprung up around the larger cities, forming city clusters, often with similar or interdependent economies. The development of city clusters in China is somewhat similar to the formation of the megalopolis in the United States, as described by Gottmann (1961). However, there are some differences in terms of the number of cities in an area, their infrastructure, and the services they provide to the region, as compared to the US. City clusters in China tend to be much more concentrated and densely populated, with little room for natural areas; for example, the distance between cities is often less than 10 km in the Pearl River delta. In the city of Guangzhou, spacing between residential buildings is so restricted that they are often referred to as “handshaking” buildings. Also, there is no clear, functional division of infrastructures among the cities, due to a lack of coordination between city planners. Cities within a cluster often compete for avail353