• Energy Research
• 15. Life on land close

Due to hectic city lives and the growing health concerns in light of the global pandemic, mountain tourism has become increasingly popular worldwide, which has increased the related research. Based on traditional bibliometric laws, such as those authored by Price, Bradford, Lotka, and Zipf, this study acquired 1413 mountain tourism journal articles via bibliometric analysis and identified the most influential journal articles, researchers, and countries in mountain tourism research as indexed in the Web of Science (WoS) database during 2010–2020. The keyword analysis revealed mountain tourism’s emerging research topics, including climate change, sustainable development, sustainability, sustainable tourism, protected areas, rural tourism, and conservation. The most influential journal was Sustainability in the mountain tourism. The research results showed that China, the U.S., and Romania produced the most significant mountain tourism articles indexed in the WoS. Most developed countries in Europe had the highest average and average normalized citations, which indicated that they may have more influence in this field as compared to other countries. Some developing countries, such as India, Nepal, and China, had higher citations, average citations, and/or average normalized citations than other countries. The main research trend was the sustainable development aspect of mountain-based tourism during the COVID-19 pandemic. We identified the research gap in WoS; although there is some research shedding light on tourism via bibliometrics, mountain tourism bibliometric analysis and science mapping via VOSViewer is scarce. The paper summarizes the critical aspects of the current discussion of sustainable mountain tourism, such as transport and coopetition (i.e., combing with cooperation and competition) in mountain tourism areas. The results indicated that government agencies and destination managers need to strike a balance between sustainable mountain tourism development and environment and natural landscape conservation after COVID-19.

We argue that environmental legislation and regulation of more developed countries reflects significantly their moral values, but in less developed countries it differs significantly from their moral values. We examined this topic by using the keywords “sustainability” and “sustainable development”, studying web pages and articles published between 1974 to 2018 in Web of Science, Scopus and Google. Australia, Zimbabwe, and Uganda were ranked as the top three countries in the number of Google searches for sustainability. The top five cities that appeared in sustainability searches through Google are all from Africa. In terms of academic publications, China, India, and Brazil record among the largest numbers of sustainability and sustainable development articles in Scopus. Six out of the ten top productive institutions publishing sustainable development articles indexed in Scopus were located in developing countries, indicating that developing countries are well aware of the issues surrounding sustainable development. Our results show that when environmental law reflects moral values for betterment, legal adoption is more likely to be successful, which usually happens in well-developed regions. In less-developed states, environmental law differs significantly from moral values, such that changes in moral values are necessary for successful legal implementation. Our study has important implications for the development of policies and cultures, together with the enforcement of environmental laws and regulations in all countries.

In this study, the root sources contributing to the urban heat island (UHI) effect between megacities, such as Hong Kong and Shenzhen, were integrated and compared using satellite remote sensing data. Classification and multilayer perceptron regression tree (CARTMLP) algorithms were used to classify land use. The radiative transfer equation method was applied to retrieve the land surface temperatures (LSTs) in the study area. Multiple linear regression analysis was applied to determine the relationship between land-use types and UHIs. The experimental results show a large area of relatively high temperature dispersed within Shenzhen, and comparatively small areas highly centralized in Hong Kong, with the retrieved LST in Hong Kong lower than that in Shenzhen. In addition, the surface temperature of large complex buildings decorated with high-albedo materials in Hong Kong was higher than in Shenzhen (e.g., Hong Kong International Airport, 25.12 °C; Shenzhen Bao’an International Airport, 23.38 °C), with artificial heat being an important contributor to these differences. These results also imply that high-albedo materials are sufficient to alleviate high temperatures. These findings are integrated to propose an organic combination strategy for reducing UHI effects in urban areas in megacities worldwide, such as Hong Kong and Shenzhen in China.