## 3 Spatiotemporal Differentiation of Coupling Coordination Degree between Tourism and Urbanization  
### Time Series Changes of Coupling Degree between Tourism and Urbanization  
The mean values of tourism development and urbanization evaluation index, development degree, coupling degree, and coordination degree, according to the tourism and urbanization index of the Yangtze River Delta Urban Agglomeration from 2008 to 2018, are shown in Figure 2.  
In terms of the evolution characteristics of time series, the mean value of tourism and urbanization evaluation of the cities in the Yangtze River Delta Urban Agglomeration gradually increased every year from 2008 to 2018. The level of urbanization is higher than that of tourism, with the coupling degree exhibiting an upward trend with a slight fluctuation. The mean value of the coupling degree in all regions is between 0.8 and 1 and highly coupled, indicating a strong correlation between tourism and urbanization. Urbanization provides special funds for tourism development, improves infrastructure construction, and expands tourism demands. Through industrial integration, tourism development can expand employment, improve population structure, optimize land resource allocation, and enhance urbanization levels. To facilitate the 2009 Shanghai World Expo, the Yangtze River Delta region jointly launched 55 Expo-themed experience routes and nearly 100 experience sites in the Yangtze River Delta Urban Agglomeration. Subsequently, it is seen that both the tourism evaluation index and the coupling degree are high, while the mean value of the coordination degree between tourism and urbanization in the Yangtze River Delta Urban Agglomeration is between 0.4 and 0.5, which reflects moderate coordination.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Coupling Degree (C)** & **Coupling Level** & **Coordination Degree (D)** & **Coordination Level** \\ \hline
0–0.20 & High decoupling & 0–0.20 & Serious disorder \\
0.21–0.40 & Decoupled & 0.21–0.40 & Reasonable disorder \\
0.41–0.60 & Low coupling & 0.41–0.60 & Moderate \\  & & & coordination \\  & & & Favorable \\
0.61–0.80 & Moderate coupling & 0.61–0.80 & coordination \\
0.81–1.0 & Highly coupled & 0.81–1.0 & Strong coordination \\ \hline \hline \end{tabular}
\end{table}
Table 2: Types of coupling degree and coordination degree.  
Figure 2: Trends of evaluation index and development, coupling, and coordination degrees of tourism and urbanization.  
The comprehensive parameter curve of tourism development and urbanization shows that the evaluation index of tourism generally presents a slow annual growth trend, while the evaluation index of urbanization generally presents a continuous growth trend. The growth of tourism is slower than that of urbanization because the regions that lack tourism resource endowment cannot optimize the use of the dividend effect of urbanization, failing to innovate advantageous tourism products. At the same time, the gap between tourism development and the urbanization evaluation index has widened because the urbanization growth rate is relatively fast, and the development of tourism in some regions fails to keep pace with the times, presenting a low-quality development situation where supply exceeds demand. Alternatively, areas that originally had better tourism development failed to pay attention to the environment, affecting the local ecological resources. In the future, based on ecological concerns, it is necessary to increase investment in special funds, high-quality professionals, and infrastructure provided by urbanization. It is imperative to implement new visions and constantly develop new tourism products in line with market demands to steadily improve the coordination between tourism and urbanization.