2.1 Sustainable tourism and community-based ecotourism initiatives

The term sustainable tourism (ST) itself emerged from the broader sustainability movement, “sustainable development”, which was thought to the first introduced in the early 1970s, and then officially popularized in the late 1980s through a report by the World Commission on Environment and Development (popularly known as the Brundtland Report) (Weaver, 2006). This report defined sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (World Commission on Environment and Development [WCED], 1987, p. 43). Based on this classic concept, the ST is thought of as the application of the sustainable development idea into the tourism industry, that is, “the needs of the present tourists and host regions while protecting and enhancing opportunities for the future” (UNWTO, 1998, p. 21, cited in Nguyen, Young, Johnson, and Wearing, 2019). To become popular as current, this discourse has gone through many different stages and statements depending on the specific author’s view and field, and it is still evolving. Initially, the ST field seems to be a broad conceptualization covering three issues: environment, society, and economy (Bramwell, Higham, Lane, & Miller, 2017). From here, alternative forms of tourism, such as ecotourism or CBET, were formed to achieve sustainable goals in tourism (Ruhanen, Moyle, & Moyle, 2019). However, due to its infancy, it was plagued by definitional debates, many different perspectives, and misunderstanding of the nature and orientation of this concept (Bramwell & Lane, 2013).

During the early 2000s, with technological advancements alongside broader societal trends, this period witnessed an explosion and an increasing interest in sustainability. In turn, tourism has enormously increased its sustainability engagement by developing a more sustainable product range, assembled with different sustainability criteria, such as a friendly environment or products produced by local people (Ruhanen et al., 2019). Organizations worldwide, such as the United Nations (UN) and the UNWTO, stepped in with tougher measures and sustainability criteria through global summits or congresses. Notably, one of the considerable efforts to promote sustainability in tourism during this period was the publication of the guidebook ‘Indicators of Sustainable Development for Tourism Destinations’ edited by the UNWTO (2004, cited in Agyeiwaah, McKercher, and Suntikul, 2017). With a length of more than 500 pages alongside 13 aspects and 40 specific criteria, this manual covers all areas of tourism towards sustainable development, from macro issues, such as governance, climate change, environmental pollution and nature conservation, to micro problems such as local livelihood, seasonality, or the authenticity of a tourist destination (Agyeiwaah et al., 2017).

It has become almost universally recognized as a truly unique desired process by academics and developers (Weaver, 2006). The ST has regularly been attached to general expectations, including environmental preservation, biodiversity, equality between stakeholders and host-guest nexus, the promotion of human welfare and local community, cultural conservation, empowerment for vulnerable groups, transparency in policy, and many others (Bramwell & Lane, 2013; Fennell, 2005; UNWTO, 2017). However, many experts have argued that achieving all sustainability criteria is near impossible and argued that it should replace or revise for more suitable. (Marzo-Navarro, Pedraja-Iglesias, & Vinzón, 2015) implied that “we are overwhelmed by too many indicators”. Similarly, Agyeiwaah et al. (2017) criticized it as ineffective mainly because it is simply too broad, comprehensive, and ambitious. Moreover, many indicators are inconsistent and not similar, so implementing sustainability principles is difficult. For example, economic sustainability can be measured immediately, while others, such as social and cultural aspects, may only be measured over many years (Agyeiwaah et al., 2017). Thus, it has been recognized that it should offer specific criteria based on each destination’s specific context and time-related circumstances (Bramwell & Lane, 2013) rather than general ones.

Therefore, this study is based on the triple bottom line (TBL) sustainability framework (economic, environmental, and social), but with minor revisions to match the reality in Vietnam. Accordingly, this study supplements two elements to create a new research framework consisting of five main components: economic benefits, environmental conservation, cultural preservation, community participation, and empowerment (Figure 1). We argue that all five aspects will contribute to sustainability in CBET sites. In terms of measuring, such factors have been widely addressed.

First, the economic benefits are considered the priority to local communities, which should be distributed fairly (Choi & Sirakaya, 2006). CBET can bring direct and indirect economic benefits to local residents. On the one hand, it can promote local employment and income opportunities and diversify livelihoods that improve residents’ quality of life (Lee, 2013; Ohe & Kurihara, 2013). On the other hand, CBET can enhance the local economy by selling local products and small shops around the destination. In this vein, economic benefits are not only for those who participate directly in the programs but also for the community as a whole.

Second, a fundamental characteristic of CBET initiatives is that the quality of the natural resources and wild species can not only be damaged, if possible, but also may be preserved by tourism (Choi & Sirakaya, 2006). Tourism activities not only raise awareness about environmental protection for guests but also for the indigenous people, who play an important role in keeping the surrounding environment clean and sustainable. Furthermore, tourism revenue helps improve local facilities and nature conservation funds (Kiss, 2004).

Third, CBET activities encourage local people to value their cultural heritage via the cultural exchange between host and guest. This also helps the local community to improve their awareness and understanding of the different cultures of different regions. Moreover, besides the types of goods, intangible services such as cultural identity and the indigenous lifestyle of the local community become attractive features for tourists. In this sense, they can be resilient and maintain ancient cultures and traditional festivals. CBET also provides opportunities for locals to increase their social or traditional cultural identity and promote the community’s social coherence (Choi & Sirakaya, 2006).

Fourth, community participation is the most important dot to destination governance, which is recognized as a central key to achieving sustainable goals (Bramwell, 2011; Hall, 2011), especially in CBET projects. Research by (Gurung & Seeland, 2008) has shown that community participation ensures that ecotourism activities engage and cooperate between local communities, local authorities, and tourists to meet local needs while delivering conservation benefits. Involvement of local communities contributes to tourist satisfaction and ensures continuity of ecotourism activities (Stone & Wall, 2004).

Fifth, empowering vulnerable groups, especially women, remains an essential principle of ecotourism (Honey, 2008). This principle of ecotourism supports the defense of democracy and human rights movements and leads to greater empowerment of vulnerable groups who comprise the majority of local communities (Honey, 2008). Furthermore, many advocates of social equality applauded ecotourism due to its potential to create social benefits for improving vulnerable groups’ lives and empowering local communities’ rights (Scheyvens, 1999).

2.2 Applying the AHP method in tourism studies

The AHP is a general measurement theory and the widest application in multicriteria decision making, which Thomas Saaty developed in the 1970s. This model refers to decision-making based on several criteria, where each will be measured in a hierarchical structure according to its importance (Saaty, 1977). To identify the relative importance of several criteria, the pairwise comparisons method is often used at each level of the AHP (Ma et al., 2018). The AHP has many advantages in the decision-making process (Masroor et al., 2021) by transforming qualitative data into quantitative measurements (Saaty & Vargas, 2012). The approach has brought a wide variety of potential applications in academic fields and seems to be an effective instrument for bringing together the theory and practice of modelling (Saaty, 1979). Indeed, the AHP offers scholars a substantially different approach to addressing the problems of decision making, planning, conflict resolution, and forecasting through ratio scales in diverse areas, especially socio-economic, political, and technological fields (Saaty & Vargas, 2012). In recent years, this framework has contributed, for example, to sustainable solid waste management (Tsai, Bui, Tseng, Lim, & Tan, 2021), water quality management (Singh et al., 2021), the safety assessment of chemical plant production process (Song, Jiang, & Zheng, 2021) , effective management of water resource (Masroor et al., 2021), and solutions for the development of a green bond market (Tu, Rasoulinezhad, & Sarker, 2020).

In the tourism industry, this approach is considered an essential tool in identifying sustainability in tourism destinations (Tseng et al., 2018) and forecasting tourism demand (Athanasopoulos, Ahmed, & Hyndman, 2009; Hu, Qiu, Wu, & Song, 2021). In previous documents, this method was often combined with other packages, such as fuzzy theory (Tseng et al., 2018), SWOT analysis (Wickramasinghe & Takano, 2009), or the geographic information system (GIS) technique (Abed, Monavari, Karbasi, Farshchi, & Abedi, 2011) to quantify “equivocal concepts related to subjective human judgements in an uncertain environment” (Tseng et al., 2018). In recent decades, among different multiple criteria decision analysis (MCDA), the hierarchical process (AHP) has been an effective and widely used method in ecotourism (Chandio et al., 2013; Wong & Li, 2008). Bunruamkaew and Murayama (2012) applied the AHP method according to five criteria: landscape and nature, wildlife, topography, accessibility, and community characteristics to define ecotourism sites in Surat Thani province, Thailand. In India, research by Kumari, Behera, and Tewari (2010) applied the AHP method to identify potential ecotourism destinations based on wildlife, ecological value, ecotourism attractiveness, environmental resiliency, and ecotourism diversity. Gourabi, Ramezani, and Rad (2013) also applied AHP and GIS to ecotourism potential based on eight thematic groups, including sunny days, temperature, relative humidity, slope, direction, soil texture, water resources, and vegetation density in Iran. Nahuelhual, Carmona, Lozada, Jaramillo, and Aguayo (2013) combined GIS and participatory methods, including Delphi and AHP, to map recreation for ecotourism development at the municipality level. Dhami, Deng, Burns, and Pierskalla (2014) applied AHP to identify and map ecotourism sites in forested areas in West Virginia in the United States.

Despite such significant contributions, there is still a lack of research on the AHP method application in the CBET in Vietnam. This study aims to explore the capability of AHP for assessing the sustainability of CBET sites, and for this study, Thua Thien Hue province, Vietnam, has been taken into consideration. Through the AHP method, a useful tool including criteria of the sustainability of CBET zones will be established as a valuable tool for the decision-makers to identify suitable ecotourism locations. No such works relevant ecotourism field have been reported in the study area. Thus, this is both crucial and pioneering work in this field of study, with the potential of significantly contributing to ecotourism site development.

3.1 Search for the potential ecotourism destinations

Thua Thien Hue province in Central Vietnam is renowned for the complex of Hue Ancient Capital, a UNESCO world heritage site with a range of scenic beauty destinations, such as tombs and ancient pagodas systems with extensive historical architecture (People’s Committee of Thua Thien Hue province [PCTTH], 2017). Further, Thua Thien Hue is known for its famous festivals and Nha Nhac (royal music). With the diversity of traditional craft villages and the preservation of cultural and historical values, tourism (in general) and CBET (in particular) are integrated into strategies for economic development, poverty alleviation, and local livelihood improvement (PCTTH, 2021). It is not surprising that tourism has been identified as a key financial sector based on its significant contribution to GDP in recent years. The determination of the main research sites was considered based on an analysis of five criteria of CBET, including tourism activities associated with nature, cultural activities, participatory activities, etc. of local communities, bringing economic benefits and empowering vulnerable groups such as women and ethnic minorities. Based on these criteria, the study conducted consultations with experts of the Department of Tourism and some pilot trips to select appropriate destinations in ecotourism regions, including the lagoonal area, coastal area, highland and remote highland areas with four specific destinations of Hong Ha, Loc Binh, Quang Loi and Thuong Lo. The general background is described in Table 1.

The four study sites are located in different regions and have unique tourism features. Loc Binh and Quang Loi are located in coastal areas, where three local rivers merge to form the largest lagoon system in Southeast Asia (Tam Giang – Cau Hai lagoon) before emptying into the East Sea. The remaining two locations belong to the two poorest mountainous districts in this province, characterized by agricultural lifestyles of ethnic minority groups. All four areas are located in rural areas. The Thuong Lo village is considered the first CBET model of the province since the early 2000s, followed by Quang Loi, while Hong Ha and Loc Binh have just been established in recent years. At first glance, although it was formed the earliest, income from tourism in the Thuong Lo destination appears low compared to other places, especially emerging tourist areas like Loc Binh. In short, the diversity of geographical locations, ethnic minority representation, history, and different types of services meet our objectives and guarantee equality and dialectical views.

3.2 Identification of criteria for the sustainability of ecotourism destinations

As noted, the province is most renowned for the UNESCO world heritage site of Hue Ancient Capital has been world heritage listed by UNESCO (PCTTH, 2017), with Thua Thien Hue known for its famous festivals and Nha Nhac (royal music).

Although various attributes in tourism, especially the ST, have been investigated previously, the complex reality and multi-goals of the CBET initiative have led to a broad range of challenges for scholarly authors (Budeanu, Miller, Moscardo, & Ooi, 2016). Based on the literature, this study provides a set of 17 criteria that represent five aspects: environmental conservation (A1), cultural preservation (A2), community participation (A3), economic benefits (A4), and empowerment (A5), as indicated in Table 2. To avoid subjective attributes to this study, the criteria were trial-tested by some local respondents and then confirmed by local authorities to obtain the final measures for guaranteeing reliability. A community-based approach to tourism recognizes the need to promote the quality of life of people, their culture and the conservation of resources (Scheyvens, 1999). The environmental issue is a crucial aspect of the tourism sector. CBET can effectively incentivise communities to take conservation action directly or indirectly (Kiss, 2004). For example, tourism incomes are very high that “people deliberately protect biodiversity to protect that income” (Kiss, 2004, p. 234). To achieve this goal, raising awareness of both the community (C1) and visitors (C2) are the factors mentioned in the previous literature (Honey, 2008; SNV, 2007). In addition, reducing and minimizing the negative impacts of the tourism industry on the environment (C3) are also goals of any CBET project. From another perspective, tourism, especially in the CBET field, comprises a complex set of social and economic activities that use large amounts of local resources and involve various functions and stakeholders (Tsai et al., 2021). CBET may enhance the social attachment and opportunities for villagers to increase their social or traditional cultural identity (Choi & Sirakaya, 2006). By assessing residents’ (C4) and visitors’ (C5) perspectives on cultural education, managers can understand the residents’ perceptions of tourism impacts and how it influences their culture and life (Lee & Jan, 2019). Moreover, cultural exchange (C6) also plays an important role in a tourism destination’s cultural preservation and community norms (Cuong, 2020).

Community participation also contributes to sustainability in a destination. The participation of local communities in tourism planning (C7), especially CBET projects, is both a mandatory criterion and a tourism product (Thái, 2018). In the former, their participation ensures fairness and transparency in tourism activities (C9) and guarantees the most profit belongs to them under legal policy (C10). The latter is a way to showcase their unique culture and their hospitality, thereby promoting more tourists (C8). To avoid the traps of many past ventures, which disempowered local communities, Scheyvens (1999) proposed four levels of empowerment in the framework: psychological, social, political and economic empowerment. This aspect is applied to emphasize the importance of local communities having a level of control over and benefit-sharing from tourism in their respective areas (Scheyvens, 1999), especially for vulnerable groups like women (C16), and poor and ethnic minority households (C17). While some authors emphasize the CBET potential in the cultural heritage of local peoples, their involvement and their environments, others mention economic benefits and profits from tourism. Economic benefit for the local community is an important aspect of CBET sustainability (Marzo-Navarro et al., 2015). Kernel (2005) has argued that the economic aspect of tourism development involves maximizing profits derived from tourism, based mainly on the tourist arrivals in specific destinations that are important for both private sectors and local community groups (C14). CBET is also implemented based on bringing economic benefits to the communities involved in tourism, especially those living in/around protected areas. This approach advocates promoting recycling and saving energy (C13) to maximize economic benefits for local communities (Weaver, 2006). Finally, supporting local economic development (C15) involves increasing the number of jobs (C11), creating a fund for environmental protection incomes (C12) and considering salaries (Tseng et al., 2018).

3.3 Identify criteria priority (weight)

As analyzed earlier, the AHP creates decision-making issues in hierarchies. In this study, we apply AHP to evaluate its relative value through three basic steps.

Step 1: Identifying the goals and the criteria and organizing them into a hierarchy

The simplest form of the customary AHP consists of three levels of goals, aspects and decision alternatives. In the study, the goal is a sustainable ecotourism index (SEI) at the top level, followed by a second level consisting of five main criteria by which the alternatives (are case studies), located in the third level, will be sorted out (Figure 2). Such hierarchical systems have advantages in judging the importance of the elements in a given level with respect to the components in the adjacent level above (Saaty & Vargas, 2012). It also provides an overarching overview of all issues after complete structuring. After that, a set of 17 sub-criteria with five main criteria (aspects) is identified and systematically organized in a hierarchy, as shown in Table 2.

Step 2: Comparing pairwise criteria

First, a 9-point scale is used to identify the relative importance of each attribute, as introduced by Saaty and Vargas (2012) (see Table 3). Data was collected using semi-structural questionnaires by two groups. To maximize the efficiency of the group decision-making process using the AHP survey, purposeful sampling was used to identify key informants and local experts in both the private and public sectors. Specifically, two tourism professionals from Hue University (top 10 ranking in Vietnam), two from the department of tourism, two from the department of rural development of Thua Thien Hue province, four district managers and eleven local key informants were interviewed. The team of experts conducted their comparative assessments for each pair of aspects. The inputs were analyzed to determine the relative priority of each aspect. Concurrently, they also proposed views concerning adding or removing some criteria in the general aspect set.

The judgement matrice forms are illustrated in Table 4. Each matrix is denoted with the equation W = (C_ij)m*n, where Cij denotes the weighting given to criterion C_i and criterion C_j for target W (Ma et al., 2018).

Next, the validity of the judgement matrices was examined by a consistency test as Saaty’s suggestions that includes three most important indexes: the Random Index (RI), Consistency Ratio (CR), and a Consistency Index (CI). As suggested by Saaty and Vargas (2012), the values of the RI are available in Table 5. The CI value is calculated based on λ_max (Equation 1), as illustrated in Equation 2. Meanwhile, the CR index measures how far a decision maker’s judgements are from perfect consistency (Kim, Park, & Choi, 2017), which is calculated as Equation 3. The judgements are consistent and acceptable if the CR value is less than 0.1. Conversely, if the CR is more than 0.1, it indicates an inconsistent judgement (Kim et al., 2017). In those cases, it will be revised until it meets the requirement.

Where: λ_max indicates the principal eigenvector, n is the matrix size, a_ij denotes an element of the pairwise comparison matrix, and w_j and w_i represent the j^th and i^th element of values of eigenvector, respectively.

Where: CI is the consistency data of the judgement matrices; RI is the average random consistency index; CR is the consistency ratio.

Step 3: Calculating weights of indicators at each level

After passing consistency tests, the weight of each aspect (W_i) in the matrix will be calculated as a mathematical formula, as Equation 4 shown below.

Where:

${\sum }_{i=1}^{n}Wi=1;$W_i denotes the weight vector of i^th aspect; n is the number of weighted aspects, and b_ij is the importance of aspect b_i relative to aspect b_j.

3.4 Determining the sustainability index of each destination

To determine the sustainable ecotourism index of each tourist destination, the study carried out three steps: (1) definition of the sustainable ecotourism index, (2) data collection, and (3) data analysis.

4.1 Weighting aspects of sustainable ecotourism from AHP analysis results

In this study, the AHP method supports three main results. First, it converts the responses (countable or uncountable) into AHP numbers that can compare between attributes (aspects) (Table 7). Then, an interrelationship matrix of the aspects is generated, and the weights of each aspect (W_i) are determined (Table 8). Accordingly, environmental conservation (A1) is determined to be the highest weight (0.28), followed by economic benefits (A4=0.22), community participation (A3=0.20), and empowerment (A5=0.13). The CI and RI values are 0.02 and 1.11, respectively. The CR value is calculated as 0.002, lower than the 0.1 threshold, which indicates that this judgement matrix is consistent and acceptable.

4.2 Descriptive sustainable ecotourism indicators in destinations

Regarding environmental conservation, the analysis results in Table 9 show that lagoon and coastal tourist destinations have high and very high scores, while tourist destinations in mountainous areas have medium to high scores. Notably, some indicators of tourists’ awareness of the environment or reduction of environmental impacts in the mountainous regions are at low to moderate levels, respectively (2.85 and 2.95).

4.3 Ranking the sustainability level of tourist destinations

After obtaining the weight of aspects, the SEI is calculated to identify the sustainability level in each tourism destination. The results indicate that the sustainability level differs between tourism destinations, as shown in Table 10. Overall, respondents evaluated that Quang Loi is ranked as the region with the mos sustainable tourism with an SEI score of 4.25, followed by Loc Binh (3.90) and Thuong Lo (3.46). Meanwhile, Hong Ha is considered less sustainable (SEI<3.4). Notably, this result illustrates significant gaps between the relative sustainable values of each aspect separately. Accordingly, the environment perspective (A1) has the highest SEI, ranging from 1.4 to 2.33. In contrast, the indicators of empowerment for the local community (A5) are the lowest, not exceeding the 0.92 threshold. This means that respondents consider five factors to be of unequal importance in contributing to the sustainable value. We will analyze the issues intensively in the next section.