To effectively solve the problem of environmental pollution, the Chinese government has implemented an environmental supervision system since 2002. The environmental supervision system mainly uses the four functions of supervision, investigation, coordination, and emergency response to strengthen environmental protection supervision and law enforcement, respond to environmental emergencies, and coordinate cross-regional pollution disputes. As an important system design for China to control environmental pollution and promote the ecological transformation of economic development, the policy effect of the environmental supervision system deserves attention. This paper uses the difference-in-differences method to investigate the impact of the top-down environmental supervision system on air quality based on the 2000–2016 data for 285 prefecture-level cities in China. The results indicate that the annual average concentration of PM_2.5 decreased significantly after the implementation of the environmental supervision system. The dynamic analysis shows that PM_2.5 decreased most markedly in the first year after the implementation of the policy, and then the effect gradually weakened. Mechanism analysis suggests that the environmental supervision system can break the collusion between government and enterprise, encourage enterprises to carry out technological innovation, change pollutant discharge behavior and push local governments to adjust the industrial structure, enhance environmental protection awareness to reduce the PM_2.5 concentration, and improve air quality. Comparing different regions, the PM_2.5 in East China, North China and Northeast China are relatively high, and the pressure for air pollution control is great. Meanwhile, we find that the environmental supervision system has a significant station effect. Compared with other cities, the cities where the environmental supervision centers are located are more deterred by the environmental supervision, and their air quality has improved to a significantly greater degree. In the future, we should further strengthen the environmental supervision of high-pollution areas and non-station cities, and pay more attention to improving the long-term effect of the environmental supervision system.

With the rapid development of the economy, acid rain has become one of the major environmental problems that endanger human health. Being the largest developing country, the environmental problems caused by acid rain are of increasing concern with the rapid industrialization and urbanization in China. Recently, many researchers have focused on acid rain. To better understand the temporal and spatial dynamics of acid rain in China, the monitoring data on acid rain from 1998 to 2018 were studied using ArcGIS 10.2. The results show that the proportion of acid rain cities, the frequency, and the area of acid rain were decreasing, however, the situation still remains serious. Overall, the chemical type of acid rain was mainly sulfuric acid rain. However, the concentration ratio of decreased by 81.90% in 2018 compared with 1998, and presented a decreasing trend, which indicates that the contribution of nitrate to precipitation acidity has been increasing year by year. This research will help us to understand the distribution characteristics and causes of acid rain in China, and it may provide an effective reference for the prevention and control of acid rain in China.

According to the results of The Second Comprehensive Scientific Expedition on the Qinghai-Tibet Plateau, the balance of solid and liquid water on the Qinghai-Tibet Plateau is disturbed, and a large amount of solid water, such as glaciers and perpetual snow, is transformed into liquid water, which aggravates the risk of flood disasters in the Plateau. Based on the historical flood disaster records of the Qinghai-Tibet Plateau, this paper analyzed the temporal and spatial distribution characteristics of the flood disasters in the Plateau, and estimated the critical rainfall for the flood disasters combined with precipitation data from the meteorological stations in each basin of the Qinghai-Tibet Plateau. The results show that most of the flood disaster events in the Plateau are caused by precipitation, and the average annual occurrence of flood disasters is more than 30 cases and their frequency is on the rise. The high frequency areas of flood disasters in the Qinghai-Tibet Plateau are mainly in the Hehuang Valley and the Hengduan Mountains area; the secondary high frequency areas are located in the valley area of South Tibet and the peripheral area of the Hehuang valley. Finally, we found that the highest critical rainfall value of flood disasters in the Qinghai-Tibet Plateau is in the southern area of the plateau, followed by the eastern and southeastern parts of the plateau, and the lowest values are in the central, western and northern parts of the Plateau.

Surface albedo directly affects the radiation balance and surface heat budget, and is a crucial variable in local and global climate research. In this study, the spatial and temporal distribution of the surface albedo is analysed for Beijing in 2015, and the corresponding individual and interactive driving forces of different explanatory factors are quantitatively assessed based on geographical detectors. The results show that surface albedo is high in the southeast and low in the northwest of Beijing, with the greatest change occurring in winter and the smallest change occurring in spring. The minimum and maximum annual surface albedo values occurred in autumn and winter, respectively, and showed significant spatial and temporal heterogeneity. LULC, NDVI, elevation, slope, temperature, and precipitation each had a significant influence on the spatial pattern of albedo, yielding explanatory power values of 0.537, 0.625, 0.512, 0.531, 0.515 and 0.190, respectively. Some explanatory factors have significant differences in influencing the spatial distribution of albedo, and there is significant interaction between them which shows the bivariate enhancement result. Among them, the interaction between LULC and NDVI was the strongest, with a q-statistic of 0.710, while the interaction between temperature and precipitation was the weakest, with a q-statistic of 0.531. The results of this study provide a scientific basis for understanding the spatial and temporal distribution characteristics of surface albedo in Beijing and the physical processes of energy modules in regional climate and land surface models.

Forests are major sources of energy, timber and non-timber forest products, medicinal and aromatic plants, hydrological functions, biodiversity conservation, and also fundamental sources of revenue collection to the nation. Studies indicate that forests could significantly enhance economic growth and create employment opportunities for local communities under intensive management. This paper aims to predict the contribution of the forest sector to the national economy. The economic facets of forestry considered in this paper are revenue generated from timber, non-timber forest products (NTFPs) and medicinal and aromatic plants (MAPs), and protected areas. The ARIMA model was used to forecast the economic contribution of the forestry sector. The study found that the total revenue generated from the selling of timber and fuelwood (USD 50.19 million) was higher than the total revenue collected from protected areas (USD 37.58 million) and NTFPs/MAPs (USD 6.9 million) in the past 15 years. The model projected that the mean revenue for the timber and fuelwood sale will USD 3.5 million for the next ten years. Similarly, the mean revenue will be generated about USD 0.5 million and USD 6.2 million from NTFPs/MAPs and protected areas, respectively, for the next ten years. The study limits to take account the in-kind use of forest products such as timber, fodder, fuelwood, etc., as used by community people within a forest users' groups. Thus, practicing sustainable forest management, enabling policy documents, establishing forest-based industries, establishing forestry nurseries, conducting agroforestry practices, and tenure security could enhance the forestry sector's economic aspects.

The catering industry is an important industry related to the growth of the national economy and the needs of daily life. After 2012, the central government has successively introduced and implemented a series of policies to limit the official consumption and catering waste. These policies have had a huge impact on China's catering industry, especially the development of high-end catering. Based on expert scoring and interviews with government managers, the catering industry organizations, catering enterprises, researchers and consumers, this paper studies the impacts of the policies before and after 2012 on the sustainable development of the catering industry. The results show that: (1) Policies after 2012 have been very strong in their strength and duration, and this can ensure that the policies can effectively perform their restraint and management functions in the long term. (2) As affected by policies after 2012, the frequency and amounts of public expenditures in China have dropped significantly, and mass consumption is developing faster. (3) The impact of policies on income is quite controversial. On the whole, the policies have continued to promote the increasing of catering income after 2012, and have played a significant role in optimizing the catering structure and reducing food waste. However, the policies have had little effect on the improvement of industry standards and environmental protection. (4) The sustainable development of the catering industry requires the efforts of the government, industry organizations, restaurants and consumers. Steady income growth, a reasonable and healthy industry structure, sound industry standards, and low food waste are important standards and goals for the sustainable development of the catering industry.

The degradation of the eco-environment has been a challenge for sustainability in resource-based cities around the world. Although much attention has been drawn to this issue, few insights have been acquired regarding the spatial differentiation and mechanism of the factors influencing habitat quality in resource-based cities from the perspective of the interactions of natural and human factors. Using Tangshan City as a case study, this paper evaluates habitat quality by integrating Ecosystem Service Value Assessment and the InVEST-HQ model, identifies the spatial distribution of Tangshan's habitat quality with spatial auto-correlation, and explores the influencing factors and their mechanism of influence on the spatial differentiation with the geographical detector model and Space production theory. The results show that: (1) The total value of the habitat quality in Tangshan City in 2019 was 3.45×10¹⁰ yuan, and the habitat quality value was 24435.05 yuan ha^–1. The habitat quality value presents a clustered distribution pattern of “hot in the north and the south, cold from the center to the west”. (2) On the county scale, Qianxi County had the best habitat quality and Lubei District had the worst habitat quality; Shangying Township had the highest average habitat quality and Kaiping Street had the lowest average habitat quality in the township unit. (3) The results of geographical detectors show that natural environmental conditions are the important basic factors affecting the spatial differentiation of habitat quality in Tangshan City, while urbanization and industrialization factors are the most important external forces driving the spatial differentiation of habitat quality. The contributions of average elevation, average slope, raw material industrial density, and population density to the spatial differentiation of habitat quality are all above 0.40. The interactions of any two factors on habitat quality are enhanced. Areas with concentrated populations, rich industrial resources, and convenient transportation become low-value habitat quality areas; while areas with beautiful landscape patterns, abundant precipitation, and a comfortable climate become high-value habitat quality areas. Space production theory can be used to explain the mechanism of the formation of the spatial differentiation of habitat quality.

Wetland is a unique natural landscape pattern, which provides a variety of important functions and services for human societies. With the rapid develop of the economy and accelerated urbanization, the inland wetlands are faced with series of problems, including reduced area, weakened wetland functions, and deterioration of the wetland ecosystem environment. Therefore, it is necessary to quantitatively assess the ecological health of China's inland wetlands, which is key to the sustainable development of ecosystems. However, most assessments of wetland ecosystems only examine single wetlands or watershed wetlands, and there are few assessments of wetland health at the national level. In this paper, based on land cover data, climate data, and social and economic data, an assessment system of inland wetland health is established by using the Pressure-State-Effect-Response (PSER) model, which includes 15 assessment indicators. Analytic hierarchy process (AHP) was used to define the indicator weights. Then we assessed the ecosystem health of the inland wetlands of China in 2010 and 2018, which produced three main results. (1) Unlike ecosystem health evaluated by administrative districts, wetland ecosystem health (WEH) evaluation based on the grid could provide additional details of wetland health. (2) The area of inland wetlands increased by 16328 km² in 2018 compared to 2010, and the average wetland ecosystem health index in 2018 was 3.45, compared to an index value of 3.24 in 2010. (3) In 2018, wetlands in the better, good, moderate and poor conditions represented about 26.3%, 46.4%, 26.9% and 0.5% of the total, respectively. These results provide a practical guide for protecting and managing wetland system resources and reliable information for land use planning and development.

The community forest program in Nepal is one of the successful conservation initiatives. Tree species in a forest ecosystem have a fundamental role in maintaining the vegetation structure, complexity, and heterogeneity. This study analyzes the composition and regeneration of tree species in five community forests (CFs) of the sub-tropical region, Lamjung district, Nepal for preparing baseline data for long-term research projects and helps the community to manage their CFs scientifically. Tree species data were generated by stratified random sampling using 35 quadrate plots (size: 20 m × 20 m). The density of adult trees in the forests ranged from 575 Ind ha^–1 (Tilahar CF) to 1196 Ind/ha (Deurali Thadopakha CF). The sapling ranged from 2533 Ind ha^–1 (Tilahar CF) to 4000 Ind ha^–1 (Thuliban CF) and seedling from 19583 Ind ha^–1 (Tilahar CF) to 37500 Ind ha^–1 (Thuliban CF). Similarly, the adult tree basal area varied from 28.34 m² ha^–1 (Tilahar CF) to 49 m² ha^–1 (Deurali CF). The adult tree diversity index (Shannon-Weiner's H) also ranged from 1.08 (Thuliban CF) to 1.88 (Tilahar CF). The tree species such as Sapium insigne, Ficus benghalensis, Lagerstroemia parviflore, Albizia sp. and Pinus roxburghii were weak regeneration. In general, the forests have good regeneration status except for Tilahar Community Forest, but based on the DBH size class distribution diagram, there is no sustainable regeneration. Among the five community forests the DBH size of adults was significantly different, and the DBH of Deurali Thadopakha was the lowest. But only few species have good regeneration and most of the species have weak, poor to no regeneration. The dominancy of fewer species like Shorea robusta, Castanopsis indica, and Schima wallichii accordingly maintain the overall regeneration of tree of CFs, so further plantation needs to be done inside the CF by triage accordingly those species whose regeneration has poor.

Determining how to achieve sustainable development and protection of historical districts is a worthwhile research topic. As a vital way to update urban space, tourism development in historical districts is an effective tool for redistributing urban functions and increasing urban vitality. This paper takes the Insa-dong in South Korea as a case study for the evaluation of tourist satisfaction in historical districts, based on 550 questionnaires. The questionnaire contains 33 evaluation indicators, and the subjects′ subjective judgment and satisfaction with Insa-dong are measured in the form of the Likert scale. Using SPSS to analyze tourists' satisfaction with historical districts, this studyfinds that: (1) The tourist satisfaction evaluation of Insa-dong includes six dimensions in total: “Embodiment of historical elements”, “The blend of tradition and modernity”, “Industry distribution and type”, “Consumer demand”, “Street layout and function” and “Landscaping”. (2) “The blend of tradition and modernity” has the highest weight while “Industry distribution and type” has the lowest one in the analysis of factors influencing overall satisfaction. (3) The analysis of the common factor weights and the common factor satisfaction levels shows that “The blend of tradition and modernity” and “Street layout and function” are the parts that need to be improved. “Consumer demand” also has a lot of room for promotion. The research results will be beneficial for enhancing the tourist experiences of historical districts and they provide a theoretical basis and practical experience reference for effective protection and sustainable development of historical districts.

As the COVID-19 pandemic continues to spread, the global tourism industry is facing enormous challenges. There is an urgent need to explore an effective path for tourism to recover and revitalize. With the normalization of the epidemic, tourism destinations will pay more attention to the prevention, warning, and coping strategies of the epidemic, and this focus will also be evident in the study of tourism destination resilience in the post-epidemic period. Some studies on the epidemic and the resilience of tourism are currently underway, but few of them are integrated with research on the resilience of tourism destinations in the post-epidemic period, although no systematic research ideas or methods have been found. Based on resilience theory, this paper summarizes the general research ideas and develops an epidemic resilience model suitable for urban tourism destinations. The present study also proposes a set of research methods based on the index system to analyze the resilience and its spatiotemporal dynamic characteristics of tourism destinations in the post-epidemic period. The methodology can be divided into three stages: Firstly, construct the conceptual model and evaluation system for tourism destination resilience; Secondly, select case sites for empirical analysis, measure the resilience of tourism destinations, and analyze the characteristics of spatiotemporal differences and subsequent factors of influence; And finally, establish an adaptive management mechanism for tourism destinations to use in response to the epidemic and in guiding the formulation of post-epidemic recovery policies.

Willingness to Pay (WTP), Willingness to Work (WTW) and Willingness to Accept Compensation (WTA) are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services and residents' willingness to contribute to and receive compensation for tourism ecology. The objectives of this study are to estimate the residents' willingness to pay, work and accept compensation for conservation at Sanjiangyuan National Park, and to analyze the relationship between residents' attitude towards tourism ecology and the ecological assets of the National Park based on a standard questionnaire survey. The dichotomous choice Contingent Valuation Method (CVM) was employed to determine the willingness. The survey conducted in 2018 collected WTP, WTW, WTA, socio-demFographical information, social trust and resident perceptions toward tourism impacts and relevant management strategies from 244 residents in two counties. Based on generalized linear modeling, income and education level are important for residents' WTP and WTA, but other social characteristics, such as gender and age, do not have significant effects. The social trust is found to be a significant factor on residents' willingness, despite the limitation on education level. Also, government funding is associated with residents' inclination to WTP, WTW and WTA, but the support levels differ among the two counties due to geographical and social heterogeneities. The estimated WTP, WTW and WTA for the Sanjiangyuan National Park in 2018 were 1.2448×10⁷ yuan, 1.247×10⁶ hours and 2.3232×10⁷ yuan yr^–1 based on the survey and published demographics. This study, for the first time, estimates the WTP, WTW and WTA for the Sanjiangyuan National Park and informs ecological conservation managers and policy makers. Ultimately, to maintain the long-term benefits arising from sustainable development, compensation should be specifically tailored and site-dependent, and development measures based on local resources should be adopted by governments to actively support eco-tourism activities.

Tourists are the main body of tourism activities, and studying the environmental cognition of tourists is beneficial for the environmental management of scenic spots. In this article, data obtained by questionnaire were used to compose a data matrix of 169×10 dimensions, and the cognitive level of ecotourists for the tourism environment was measured by two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA) in Luya Mountain Nature Reserve. This analysis revealed three main points. (1) TWINSPAN divided all the samples into the strict environment protection type, the ordinary environment protection type, the occasional environment protection type, and the natural enjoyment type. Both the strict and ordinary environment protection types agreed with biocentrism and had a consciousness regarding the protection of nature, but the former advocated that tourism activities should be restricted in nature reserves, while the latter did not agree with restrictions on tourism activities. The occasional environment protection types denied biocentrism; on the one hand, they thought that nature should serve human beings, but on the other hand, they showed a tendency toward environmental protection. The natural enjoyment type argued that natural resources should be maximized to meet human needs. (2) There were significant correlations between the first axis of the DCA and gender, age, education, number of trips, and cognition of nature reserve function, and the second axis of DCA was significantly correlated with gender, age, and education level. Under the impact of all the factors in the DCA figure, ecotourist types transitioned gradually from the first type to the second, the third, and the fourth types along the diagonal line, and accordingly, their cognitive level for the tourism environment was reduced slowly. (3) For nature reserves, the strict environment protection type had 74 people, who was the most popular. The ordinary and occasional environment protection types had 43 people and 31 people, respectively, who should be strived to raise environmental awareness. The natural enjoyment type had 21 people, who must be systematically educated.