*5.3. Analysis of Sustainable Development Measures Based on the Entropy Weights and Time Sequence Changes of the Indicators*

The entropy weights of number of travel agencies, passenger-kilometers by highways and passenger-kilometers railways were largest among the supportive entropy input index in Dunhuang tourism destination ecosystem between 2000 and 2012 (Table 4). These indicate that significant increases of these three indexes had played an important role in strengthening the supportive entropy input system. However, the entropy weights of annual water supply were the smallest, and the entropy weights of passenger-km by civil aviation was smaller, showing some negative effects caused by the sharp decline of annual water supply and decrease of passenger-km by civil aviation in the Dunhuang tourism destination ecosystem. Those two indexes restricted the development of the supportive entropy input system. The shortage of water resources is a limiting factor for development of Dunhuang being located in the arid oasis area of northwest China. The transport passenger-kilometers focused on railways and highway, however, civil aviation supplemented the railway and highway with the development of the economy. The positive aspects of transport (railways, highway and civil aviation) and travel agencies should be improved for the supportive entropy input, as well as coordinating the relationship between water resources and to safeguard water supply by increasing effective use.

The entropy weights of number of visitor arrivals and water used by tourists were largest among the stressful entropy output index during the study period (Table 4). The value of those two indexes significantly increased the pressure of stressful entropy output index of Dunhuang tourism destination ecosystem. Those two indexes should be paid much attention, the number of visitor arrivals reasonably controlled and tourists guided on water use.

The entropy weights of industrial wastewater discharged and total wastewater discharged were largest among the consumption metabolism index of entropy between 2000 and 2012 (Table 4). Those indicate that the significant increases of wastewater discharged was strongly influenced by the consumption metabolism index of entropy and increasing the pressure on ecological environments of the tourism destination. The value of entropy weights for waste discharge by tourists was larger than that of carbon emissions, which indicates that the consumption metabolism of tourism destination is influenced more by increase of waste discharge by tourists than carbon emission by tourism. Given these circumstances, scientific controls should be put in place for the waste discharge of tourists.

The value of entropy weights for two indexes (proportion of industrial solid waste treated and utilized and investment in anti-pollution projects as percentage of GDP) were largest among regenerate metabolism index of entropy (Table 4). These show that those two indexes greatly impact the potential of regenerate metabolism system. Pollution should be controlled paying attention to the ecological security of the tourism destination, increasing investment in anti-pollution projects as a percentage of GDP and increasing proportion of industrial solid waste treated and utilized. The values of entropy weights were smallest in regenerate metabolism index of entropy, which include direct engaged persons in tourism industry as percentage of employees, rate of harmless garbage disposal and gardens per capita. These indicate improvement in the potential of regenerate metabolism system by increasing the direct engaged persons in the tourism industry as percentage of employees, improving the rate of harmless garbage disposal and increasing the gardens per capita.


**Table 4.** Information entropy and entropy weights of the sustainable development potential evaluation indicators for the tourism destination ecosystem in Dunhuang.

#### **6. Conclusions and Discussion**

The analysis of the tourist destination ecosystem entropy change indicates an increase in the diversity and complexity of Dunhuang tourism destination's socio-economic ecosystem with the rapid development of the tourism industry; the demands placed on the natural ecosystem have increased. However, the pollution problems have been controlled, as shown by the overall upward trend for regenerate metabolism during the study period. The vitality of the tourism destination

ecosystem was obviously strengthened from 2008. Based on the score of sustainable development potential for the tourism destination ecosystem between 2000 and 2012, the pressure on the natural ecosystem was increased, while the carrying capacity of its socio-economic system also strengthen. The regenerate metabolism system increased due to significant conservation achievements and development of the eco-environment in the Dunhuang tourism destination ecosystem. According to the entropy weight of this indicator and its impact on the sustainable development potential of Dunhuang tourism destination ecosystem, the countermeasures are as follows: Increase the potential of the supportive entropy input system by increasing the travel agencies and transportation; Reduce the pressure on the consumption metabolism system by decreasing the total wastewater discharged and industrial wastewater discharged; Enhance the potential of regenerate metabolism by focusing on the ecological security of the tourism destination, increase investment in anti-pollution projects as percentage of GDP and improve proportion of industrial solid waste treated and utilized.

The paper summarizes the former research results, and then further demonstrates by entropy change analysis, information entropy and negative entropy of dissipative structure system for evaluating the tourism destination ecosystem's sustainable development evolution feasibility. The numerical values show the orderly level of the tourism destination ecosystem demonstrating the system sustainable development potential. Combining the entropy weight of index and times series index will be more targeted for improving measures of Dunhuang tourism destination ecosystem's sustainable development. According to the data's availability, the article selects indexes focusing on supportive, stressful, consumed and regenerate indexes. The tourism destination ecosystem as a society-economics-environment artificial compound ecosystem, the tourists and local residents are significant participants and propellants of tourism sustainable development [27]. Their appreciation of tourism sustainable development plays an important role in system improvement; thus the indexes which are in line with their values should be chosen. On the other hand, using information entropy from the perspective of the development of tourism destination ecosystem evolution to analyze tourism destination sustainable development potential, it is beneficial to vertically analyze a single tourism destination. There are disadvantages in horizontally comparing tourism, and therefore this research must be improved.

#### **Acknowledgments**

This research is supported by China Scholarship Council (CSC), The Fundamental Research Funds for the Central Universities (lzujbky-2013-m02), Natural Science Foundation of China (41471462, 41461119).

#### **Author Contributions**

Huihui Feng, Xingpeng Chen, Peter Heck and Hong Miao designed the paper and all contributed to data collection and calculation.

#### **Conflicts of Interest**

The authors declare no conflict of interest.
