4.3.2. Calculation of Symbiosis Coefficient

According to Formulas (8) and (9), the symbiosis coefficient of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD) in the Yellow River Basin was calculated, as shown in Table 8. The results all meet the feature that the sum of the symbiosis coefficients is 1 in Formula (10). In general, the average symbiosis coefficient of the Yellow River Basin is 0 < θ*<sup>M</sup> <sup>C</sup>* = 0.3885 < 0.5, 0.5 < <sup>θ</sup>*<sup>M</sup> <sup>E</sup>* = 0.6115 < 1, indicating that TEHQD has a relatively large impact on TCEE.

**Table 8.** Symbiosis coefficient of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD).


From a provincial perspective, the results show that, firstly, the symbiosis coefficient (θ*<sup>M</sup> <sup>C</sup>* ) of Qinghai, Sichuan, Ningxia, Inner Mongolia, Shaanxi, Shanxi, and Henan is between 0 and 0.5, indicating that TEHQD has a greater impact on TCEE. That means TEHQD can play a positive impact on TCEE. Its development process fluctuated from 2010 to 2019, which is related to multiple factors such as provincial tourism development, economic development speed, and environmental background. Secondly, the symbiosis coefficient (θ*<sup>M</sup> <sup>C</sup>* ) of Gansu and Shandong was between 0.5 and 1, indicating that TCEE has a relatively large impact on TEHQD. That is to say, the improvement of TCEE can promote the TEHQD to some extent. Among them, in recent years, Shandong province gradually changed into a TEHQD with a greater impact on TCEE, while Gansu province was in the promotion stage of TEHQD before 2014 (0 < θ*<sup>M</sup> <sup>C</sup>* < 0.5) and began to change into a TCEE with a greater impact after 2014. Thirdly, the symbiosis coefficient (θ*<sup>M</sup> <sup>C</sup>* ) of Inner Mongolia, Shaanxi, Gansu, and

Shandong was close to 0.5, which can be approximated as the state of interaction between TCEE and TEHQD, forming a relatively benign symbiosis state.

In conclusion, with the continuous development of economy, society, the demand of the nation, and people changing and under the influence of the national policies about the Yellow River Basin, tourism's carbon efficiency has improved, and the tourism economy is changing to high quality development. In this procession, the TEHQD has undoubtedly contributed to the local economy, environment, and other aspects. At the same time, the improvement of TCEE can not only benefit the carbon environment, but it can also play an important role in the efficient and high-quality development of tourism, thus promoting the TEHQD. It can be seen that TCEE and the tourism economy in the Yellow River Basin form a corresponding symbiotic interface in the symbiotic environment, influencing, promoting, and developing each other in the symbiotic state.
