## 4 Results
### Spatiotemporal Changes in the Level of Urbanization and the Livelihood Level of Urban Residents
#### 4.1.1 Spatiotemporal Changes in the Level of Urbanization  
In 2004, areas with relatively high urbanization levels were distributed in developed industrial regions, such as Orkhon, Ulaanbaatar, Darkhan-Uul, Govisumber, Dundgovic, and Umunugovic. Orkhon is rich in copper and molybdenum mines, and has several factories (e.g., a logging plant, a carpet factory, and a food factory) (interview with Professor [PERSON], former director of the Institute of Geography and Geoecology MAS, 26 October 2017). In 2004, the per capita GDP of Orkhon was 3487.03 million tugrugs, which was more than five times the average level of Mongolia [36]. In addition, the five regions of Ulaanbaatar, Darkhan-Uul, Govisumber, Dundgovic, and Umunugovic are also rich in mineral resources, and industries are well developed [64; 65; 66; 67]. Moreover, most of these areas are located along the Trans-Mongolian Railway [68], and the convenience of transportation also supports the economic development of these areas. From Table 1, we know that per capita GDP has contributed to a higher urbanization level. Thus, the developed economies in these regions have increased the level of urbanization in these regions. However, in most other areas where agriculture and animal husbandry are the leading industries, urbanization levels are in the embryonic and preliminary stages due to poor economic development, such as Uvs, Govi-Altai, and Zavkhan [69; 70; 71].  
Since 2007, the urbanization level of the border areas has continuously improved (e.g., Govi-Altai, Bayan-Ulgii, Zavkhan, Umunugovic, Dornogovic, Sukhbaatar, and Dornod). The main reason has been the perennial opening of China and Mongolian border trade ports since 2005, which has promoted the development of mineral, tourism, transportation, and other industries in most parts of Mongolia [72]. The development of these industries has driven economic growth and increased the urbanization level of these regions. For instance, the Sibekulun port of Umunugovic is the only bilateral open port in Mongolia that corresponds to China's Ceke port. The economic benefits that have been brought by foreign trade between the Sibekulun and Ceke ports have spread to five of Mongolia's provinces: Umunugovic, Govi-Altai, Bayankhongor, Arkhangai, and Uvurkhangai [72; 73]. Additionally, the other seven provinces of Govi-Altai, Bayan-Ulgii, Dornogovic, Sukhbaatar, Dornod, Selenge, and Zavkhan have also boosted economic development by promoting border trade with China or Russia [72; 73], which increased their urbanization level from 2007 to 2016 (Figure 2C-E).  
From 2010 to 2013, the level of urbanization in the regions with a rich coal industry (e.g., Umunugovic, Ulaanbaatar, and Selenge) was further improved by the development of the coal industry. For example, in Umunugovic, the per capita GDP in 2010 and 2013 reached 3,906.24 and 6817.46 million tugrugs, respectively, which was more than 1.2 and 1.4 times, respectively, the average level of Mongolia [74; 75]. The level of urbanization of Umunugovic also rose from the developing stage to the developed stage (Figure 2C,D). However, after 2015, coal demand continued to decline, and the development of the coal industry was sluggish [76], which seriously affected the economic development of some regions in Mongolia, such as Umunugovic. In 2016, the per capita GDP of Umunugovic was 4406.13 million tugrugs [9], which was significantly lower than the average level ofMongolia. The urbanization level of Umnugovic also fell from the developed stage to the developing stage (Figure 2E). In contrast, regions such as Ulaanbaatar and Selenge maintained a relatively high level of urbanization through developed light industry [9].