**5.3 Improvement of regional carrying capacity under sustainable development goals**

Use comparative advantage, guide population and industry to move to the area with higher carrying capacity. Northeast China is rich in resources and has the resource base to develop the primary industry and the secondary industry. However, after the service industry of the tertiary industry has become the main engine of economic development, most areas in northeast China are affected by natural and climatic conditions, which makes it difficult for them to gather and attract more population and industries, and resource-based cities that used to absorb a large number of jobs are gradually facing the pressure of population outflow. In the future, it needs to guide the migration of population and industries to the big cities in northeast China, improve the core carrying capacity of big cities, and develop the industries of higher education, scientific research, military industry and heavy industry with northeast characteristics in big cities. In other large areas, at least in the short term, resource-based cities in northeast China, as an important energy supply base, still need to continue to assume the responsibility and pressure of supplying resources and energy in order to ensure the rigid demand for resources and energy and national strategic security.

In the long run, we should strengthen the endogenous driving force of economic growth in resource-exhausted cities by cultivating diversified industrial systems. Utilize local advantages to develop diversified industries. Take Fuxin, a coal city in Liaoning province, as an example, it has vast land and great agricultural development potential, and the agricultural products processing industry is booming. Fuxin is rich in fluorite resources, and the fluorine chemical industry based on this raw material has begun to develop. Taking coal gangue produced in coal mining process as raw material, a number of building materials enterprises are emerging gradually. In view of the increasingly depleted resources, we should plan ahead to promote the development of emerging industries. For example, Volvo's plant in Daqing, is a model for the introduction of new industries. Daqing, which has no automobile industry base at all, has initially set up a high-end automobile factory, injecting new vitality into this increasingly exhausted resource-based city. In 2017, Daqing exported more than 25,000 vehicles, with an export volume of \$897 million, accounting for 74% of the city's total exports. Therefore, it is feasible to construct capital intensive industries such as automobiles in remote, cold and remote areas due to their low labor cost, high degree of automation and low transportation cost.
