Why is the industrial zone in the city always in the east of the city? Is it the monsoon?

First of all, correct your statement that "the industrial zone of a city is always in the east of the city" is incorrect. In fact, the industrial areas in most cities are not in the east of the city. For example, Shanghai's traditional industrial zones are generally located in the west, north and south of Shanghai's urban area, but the eastern part of the urban area has the least traditional industries (now Pudong New Area is developing high-tech industries with less pollution). Another example is Chongqing, which is dominated by heavy industry. Among its major heavy industries, the steel and machinery industries are mainly located in the southwest of the city, and only the chemical industry is located in the northeast.

There are many factors to be considered in the industrial layout of a city, such as terrain conditions and traffic conditions. At the same time, pollution factors should also be considered according to the nature of industrial categories. Generally speaking, the industries polluted by smoke and dust should be arranged in the downwind direction of the city (if the wind direction in Xia Dong is opposite, the industries polluted by smoke and dust should be arranged in the crosswind direction), and the industries mainly polluted by water bodies should be arranged in the downstream of urban rivers.

Take Chongqing as an example. Chongqing belongs to monsoon climate zone, with southeast monsoon prevailing in summer and northwest monsoon prevailing in winter. Therefore, enterprises with important pollution cannot be located in the northwest and southeast, and the iron and steel industry is mainly polluted by smoke and dust, so it is more reasonable to locate in the southwest (crosswind direction) of the city. At the same time, because the main iron mines and coal mines in Chongqing are located in the southwest of the city, there is a more important consideration to locate steel enterprises in the southwest. The layout of iron and steel enterprises can be close to mines in the southwest. At the same time, in the Jiulongpo area in the southwest of the city, the Yangtze River forms a natural harbor here, which is conducive to the transportation of ore and steel.

The chemical enterprises in Chongqing are mainly distributed in the northeast of the urban area, because on the one hand, it is in the crosswind direction, and the smoke from chemical plants will not float to the urban area. At the same time, the Yangtze River in Chongqing flows from southwest to northeast, and arranging chemical plants downstream of the urban area will not cause water pollution to the urban area.

The layout of Shanghai has the same consideration. For example, Baosteel, a large steel enterprise, is located at the intersection of Huangpu River and Yangtze River in the north of the city. The first consideration is the convenience of shipping (the iron ore used by Baosteel is mainly imported and shipped by sea), and the second is that it will not cause smoke pollution to the urban area because of its northerly direction.