Abstract: To quantitatively study the impact of short-duration high-strength human tourism activities on urban air quality, a novel model (EEMD-DCCA) integrating ensemble empirical mode decomposition (EEMD) and detrended cross-correlation analysis (DCCA) was proposed and applied to study the impact of the number of tourists in Wulingyuan scenic spot of Zhangjiajie on local atmospheric NO2 concentration in 2015. The high-frequency components of the number of tourists in Wulingyuan scenic spot and the concentration of NO2 in Zhangjiajie City were obtained firstly through EEMD. And then, DCCA method was used to analyze the correlation between high-frequency components of the number of tourists and NO2 concentration. The results show that there is a significant positive correlation between the two groups of the high-frequency components of the tourist number and NO2 concentration in Zhangjiajie, and the positive correlation has a long-term sustainability feature, which means that the rapid increase of the number of tourists in short-duration holidays will continue to affect the future change trend of NO2 concentration in a certain time scale. The research in Wulingyuan scenic area shows that the model proposed can provide a new research approach for quantitative assessment of the impact of tourism activities on the air quality of natural scenic spots.

Key words: tourism;NO2, ensemble empirical mode decomposition, detrended cross-correlation analysis; long term correlation