Evaluating Perceptions of the Natural Environment in Relation to Outdoor Activities for a Healthy and Sustainable Life: A Delphi Methodological Approach

Abstract

In recent years, many studies have been carried out regarding the benefits that nature could bring to people’s well-being. The research presented here applies the Delphi methodology to design a survey aimed at assessing the links between the natural environment, well-being and leisure, enriching the existing body of knowledge. Eighteen experts participated in this study with an integrated approach to sustainability terms. Two rounds of queries were put to the panel of experts between February and July 2021. In the first round, the experts identified the key aspects to be considered when studying the perception of natural environments related to well-being through outdoor activities. In the second query, the experts assessed the importance, relevance and clarity of the questions to be included in the survey. The survey was designed based on the results of these two rounds of queries. This methodology aims to gain a better understanding of the interrelation between people and the natural environment in order to determine the mechanisms by which a relationship with nature can improve people’s health, well-being and sustainable behaviours. The Delphi method could be employed for global research to validate this survey.

1. Introduction

The loss of human contact with nature has led to research on the benefits of connection with the natural environment for human well-being [1,2]. The benefit of a relationship with nature for physical and mental health is well recognised [3,4]. The confinement suffered by the population due to the COVID-19 pandemic has highlighted the positive effects of the natural environment on people’s health [5,6,7].

A look back at the research on restorative natural settings reveals that the topic has received increasing attention [8,9]. Results from previous research show how contact with nature can promote faster recovery than in other environments [10]. However, most of the research until now has focused mainly on psychological well-being [11,12,13].

The natural environment offers the possibility of practicing outdoor activities to provide people with positive experiences [14]. People enjoy the most natural, revitalising and restorative places [15], particularly when performing some kind of activity [16]. General satisfaction with life and specific satisfaction with quality of life and leisure are associated with opportunities to carry out activities in nature [17]. Those activities associated with greater personal participation in the natural environment bring better results in terms of individual well-being [18,19].

Some researchers have found a positive link between psychology and sustainable behaviours [4,20]. Most of the correlates of sustainable behaviour are indicators of quality of life [21]. From a biophilic perspective [22], people’s recognition of the well-being produced by being part of nature likely results in their becoming concerned for the natural environment for their own benefit, which is key to a sustainable future. Feeling that one; is part of nature can explain the positive benefits of experiences in the natural environment [23]. People who are more closely in contact with nature tend to seek out more experiences with nature and benefit from the well-being it brings [24]. Awareness of these impacts in turn serves as an anthropocentric motivation to care about the well-being of the natural environment and to promote sustainable behaviours. We need to be aware of the value of the natural environment for recovering the essence of being human and to ensure the sustainability of natural ecosystems. This study takes a positive approach to the natural environment and overlooks the adverse consequences of human interaction with nature, including phenomena such as floods, tornadoes and droughts.

The studies conducted so far in this field present different approaches and are mostly observational; there are very few primary investigations. There is very little research on the causality of the relationships between contact with nature and health [4]. The most recent studies focus on surveys of participants engaged in the activity of forest walking and show high rates of well-being and connection to nature in women and in the southern hemisphere [25], while in Italy [26], about 40% of the participants in forest therapy suffer from a chronic illness that requires daily medical treatment.

Contact with nature as a preventive and restorative function could improve quality of life and lead to better personal health [27]. This element should be integrated into the planning and design of healthy urban spaces with green areas that facilitate well-being and quality of life for citizens [28].

A more therapeutic and social approach to environments that foster well-being and sustainability is required for a population in demographic transition. Studies are necessary to determine the optimum frequency of activities in the natural environment to ensure people’s integral well-being in order to quantify the necessary dose of nature [29,30] and determine the associated value of the economic benefits. Factors such as proximity to the natural environment and accessibility to the resources needed to bring about sustainable behaviours could be leveraged to promote the pattern of sustainable behaviour and provide a ‘nudge’ in bridging the gap between awareness and sustainable actions, although this has yet to be studied.

The ecological approach to visual perception developed by Gibson [31] focuses on the point of view of the active perceiver in order to explore and detect the properties of the natural environment. Perception and action are therefore part of the perceptual system of the environment [32]. Research studies on environmental perception based on images and photographs are static and do not incorporate the dynamics of experience in relation to the natural environment, so the results of these studies have been questioned [33]. Emotions play a pivotal role in the affective connection with nature and can predict sustainable behaviours. The analysis of these emotions can contribute to understanding people’s relationship with nature and its relationship with sustainable behaviours. The way people perceive and evaluate the natural environment [34] could affect their health [35].

According to the existing research [36], the connection with nature may be associated positively with concern for the biosphere and negatively with selfish concern [37]. Values can be predictive of environmental beliefs, norms, intentions and sustainable behaviours. Based on the literature review and the knowledge gaps identified, this research contributes to enlarging the existing body of knowledge by providing a new methodology with multidisciplinary approaches and the items validation process, offering new methodological applications and conclusions.

This work contributes to addressing the knowledge gap regarding the effects of contact with nature according to people’s socioeconomic and cultural profile, lifestyle, personality, state of health, type of natural environment, type of contact with nature and type of outdoor activity. It also uncovers some of the mechanisms by which nature can affect people’s health and their relationship with nature [38].

The objective of this study is to assess the positive impact of activities in the natural environment for people’s integral well-being by integrating multidisciplinary approaches.

In recent years, interest in the restorative function of natural environments has advanced, thus offering an excellent opportunity for this study to integrate the research fields of environmental psychology, leisure and public health [39].

The research addresses well-being in a more comprehensive sense, taking into account the psychological, physical, emotional and social well-being that may derive from the experience of activities carried out outdoors in natural settings [40].

The research started before the onset of the COVID-19 pandemic and concluded at the end of the pandemic situation in Spanish regions.

The study is presented with an ecological approach to perception [31] from a transactional perspective [41], integrating the affective experience with the cognitive processes of active people in natural settings.

The research aims to answer three key questions:

(a)

What are the most relevant socioeconomic, health-related, environmental and social factors involved in the positive perception of nature in outdoor activities?

(b)

What is the positive impact of different activities in natural environments on well-being?

(c)

Is the Delphi method adequate in developing a questionnaire to determine the factors involved in the positive perception of nature in outdoor activities?

2. Materials and Methods

A search of the open information was previously carried out in the scientific journal search engines related to the objective of this research. A long list of bibliography and scientific articles were identified, of which some of the most interesting have been referenced in this document.

This study was conducted considering the Nature Connection Index [42], and the theory of Values, Beliefs and Norms (VBN) [43]. An analysis was carried out of the existing literature on the services offered for people’s well-being by natural ecosystems.

This study applies a positive integrated approach to analyse the effects of nature on human health and well-being from different disciplines.

The research expects to find contact with nature to be a moderator and mediator through outdoor activities for comprehensive well-being.

Moderators are independent variables that interact and are relevant for the study of the links between nature and health [44]. Connecting with nature can reduce the negative impact of stress, adversity and environmental or social risk [45]. The positive impact of contact with nature on well-being can vary according to age, sex, residence, socioeconomic profile, culture, personality, or other factors.

Studies with mediators and moderators are very practical, as they are intervening causal variables that explain why or how one variable affects another, and they provide information on the mechanism of action [44]. Thus, outdoor activities offer the opportunity to come into contact with nature and promote physical activity.

The reliable and often-used Delphi method of expert consensus was applied to integrate knowledge of a topic from different perspectives. Twenty-five professional experts from the areas of health, psychology, leisure and entertainment, and the natural environment were invited to participate. Finally, 18 experts agreed to collaborate in the study and contributed their knowledge and experience to configure the final survey.

The queries for the 18 participating experts were organised into two rounds of questions to build the survey necessary for the research.

In the first round of queries, the experts were asked about the essential aspects to be considered in the survey, while in the second they were asked to assess the degree of relevance and importance of the questions suggested and their clarity.

The online survey was prepared with the results of the queries evaluated by the interdisciplinary panel of experts and worked on a snowball sampling. Answers were completely anonymous.

The online survey methodology has a series of advantages that have been positively valued in this research, including its lower cost, ease of use, the simplification of fieldwork logistics and the possibility of reaching population segments that are difficult to access through personal and telephone surveys [46].

This study opted for the non-probabilistic snowball sampling technique, the most common in online studies due to its low cost, high potential for viral dissemination, simplicity and accessibility. This is not to overlook its main challenges, which include biases, the difficulty of achieving an adequate sampling frame, the exclusion of non-digitised groups, low total response rates, the dropout rate during its completion and the control of the sample. These limitations can affect the reliability and validity of the research findings. It is essential for researchers to be cognizant of these challenges and to deliberate on hybrid or alternative sampling methodologies as a means of improving these issues [47,48].

The first phase of the method consists of sending the survey to the closest personal contacts and encouraging them to answer it. They in turn forward it to their contacts and disseminate it on their social networks, and so on. This means that the number of contacts in each step increases exponentially. However, the reality is that most contacts do not respond and—at most—forward the invitation to some of their contacts, making it necessary to personalise the sending process to encourage the recipient to complete it. This improves the average response rate, which goes from 10% in the best case of a non-personalised online delivery to 70% [46] if the sending is customised.

With this snowball sampling technique, this research obtains a number of responses that are sufficiently representative of the population in terms of autonomous regions, socioeconomic profiles and outdoor activities. The technique of semi-structured interviews was conducted with representative groups that were not covered by the responses received before.

3. Results

3.1. Questionnaire Design

Before the implementation of the Delphi method for the preparation of the questionnaire, the information sources, methodologies and documents were investigated to reveal the state of the art of the subject in question.

Twenty-five experts were initially selected to be part of the Delphi panel of experts based on their expertise in the subject of the study. Each of the experts selected was personally invited to be part of the panel and to collaborate in the creation of the questionnaire anonymously and without any incentive. In the communication containing the invitation, each expert was informed of the objective of the study. The purpose of this first questionnaire was to obtain a list of basic questions to ask the various target audiences in order to evaluate the positive impact of the natural environment on people’s well-being while engaging in outdoor activities.

Finally, 18 professional experts confirmed their participation in the study. The panel of experts was therefore composed of leading professionals and academics from various representative sectors related to the natural environment, well-being and leisure. The experts who collaborated are university-educated Spanish professionals over the age of 45 with a doctoral degree.

The distribution of the participating experts by areas of work is shown in Figure 1, with the percentage of women in each area. Forty-two percent of the experts have knowledge and experience in the field of the natural environment, thirty-two percent from the well-being field and a final twenty-six from the leisure field. The natural environment area has the lowest percentage of women, at 38%.

Two rounds of queries were then carried out by electronic messaging with the panel of experts requiring half an hour’s dedication in each round. Each expert contributed with their vision and knowledge on the matter. The query periods started in February and ended in July 2021 and included both queries.

3.2. First Round of the Panel of Delphi Experts: Essential Aspects

In the first round, the experts were asked about the essential aspects to be covered by the survey in order to achieve the research objectives. This was carried out by preparing a prior document with the proposed aspects regarding the initial knowledge of questions that were shown in previous investigations to be key for the person’s relationship with nature in outdoor activities.

The first query is as follows: “Please indicate and express what aspects you would ask about to assess a person’s well-being when in contact with nature in outdoor activities, in the following relationship sections”:

• In relation to their knowledge of the environment.
• In relation to their needs, interests and motivations to carry out the activity.
• Based on their expectations.
• Regarding their customs and habits.
• Regarding their emotional state.
• Regarding their health.
• Regarding their attitudes and sustainable behaviours in the natural environment.
• Regarding their sensitivity and connection with nature.
• Other aspects.

The responses received for each section were analysed by the experts who gave their opinion of the implication in the field of well-being, leisure and the natural environment. The graph in Figure 2 illustrates this implication measured by the total number of words in each section, including any repeated words. Section D corresponding to customs and habits received the most contributions and was the one with the fewest attitudes and sustainable behaviours in relation to the natural environment.

Experts in the natural environment made the most contributions to health-related aspects. Experts in the wellness area spoke more about the cognitive aspects of the natural environment. Experts in the area related to leisure made more contributions in relation to customs and habits.

The experts identified a new section to include in the survey regarding the use of technology during activities in natural environments.

Thanks to the contributions received from the members of the panel of experts, the proposed questionnaire was prepared and presented to the experts for its assessment in the second round of queries.

3.3. Second Round of the Panel of Delphi Experts: Questionnaire

The second query was as follows: “Please indicate in the blue boxes the degree of RELEVANCE and IMPORTANCE of each question for the study, and its CLARITY, on a scale of 1 to 5, with 1 is the lowest and 5 is the highest. If you consider any question redundant, please indicate this in the comments column”.

The items considered in the proposed questionnaire valued by the experts are as follows:

• On the need to carry out any activity in natural environments.
• The priority of activities in nature over other types of leisure.
• The type of activity in contact with nature.
• The type of natural environment.
• The situation and proximity of the natural environment.
• Accessibility to the natural environment.
• The frequency of the activity.
• The duration of the activity.
• The activity is carried out in company or alone.
• The highlights of the experience in the relationship with nature.
• Satisfaction with the activity.
• Proposals to improve the activity.
• Activity recommendation and reasons.
• Wondering if contact with nature influences physical and emotional well-being.
• More identified with an anthropocentric or biophilic sense of nature.
• Information media for discovering the natural environment.
• Valuation of the natural environment.
• How to improve the quality of the natural environment.
• Knowledge of species in the natural environment.
• Knowledge of legal protection standards for the natural environment.
• Reason for doing outdoor activities in contact with nature.
• Requirements of the natural environment to achieve the objective.
• Emotional state before starting the activity.
• Emotional state when performing the activity.
• Emotional state after performing the activity.
• Senses most used in activities in contact with nature.
• If it is more rewarding on a sunny day.
• If the activity in contact with nature is therapeutic.
• Health benefits.
• Share the experience on social networks.
• Mobile phone disconnection when in nature.
• Use of mobile devices to know the natural environment, take photos and videos in nature, to check your vital signs or other health indicators.
• The cost of the activity an obstacle.
• Influence of the COVID-19 pandemic in increasing activities in natural environments.
• About daily sustainable behaviour.
• About ecological awareness.
• About how this activity has changed the relationship with nature.
• About environmental concerns.

The figures below (Figure 3, Figure 4, Figure 5 and Figure 6) show the aggregated items by field of study (behaviour, culture, health, leisure, and relationship with nature). These fields are the conceptual grouping of the actual questionnaire items (

Table 1. The aggregated items by field of study.

Field of Study	Questionnaire Items
Relationship with nature	1–6; 10–13; 16–22; 26–27; 33; 37
Leisure	7–9; 30–33
Health	14; 23–25; 28–29
Culture	15; 38
Behaviour	35; 36

). The behaviour field refers to sustainable proactive actions to safeguard the natural environment. In the average score for the mean and variance of the experts’ evaluations of the questions to assess the relevance, importance and clarity of each of the questions, a value of 1 is the lowest and 5 is the highest on the Likert scale. Complementary to this aggregate information, Appendix A provides the score for each question.

Figure 3 shows the relevance of the questionnaire items. The well-being experts give the maximum mean value (4.6) with the highest degree of agreement (variance 0.6) for relationship with nature. For the other fields of study (leisure, health, culture and behaviour), the evaluations by the leisure experts have the greatest mean value and greater agreement than the other experts.

Regarding the importance of the question items (Figure 4), the well-being experts give the maximum mean value (4.9) and the highest degree of agreement (variance 0.2) to the health field. For the other fields of study (relationship with nature, leisure, culture and behaviour), the evaluations by the leisure experts have the greatest mean value and are more in agreement than the other experts.

Finally, in regard to the clarity of the questionnaire items (Figure 5), the natural environment experts give the maximum mean value (4.7) and have the highest degree of agreement (variance 0.6) for the leisure field. For the other fields of study (relationship with nature, health, culture and behaviour), the evaluations by the leisure experts have the greatest mean value and are more in agreement than the other experts.

The natural environment experts give the lowest values for the relevance (3.8) and importance (3.9) of culture items (Figure 6).

The highest evaluation by the leisure experts is for the importance of behaviour items (5.0), with all the experts agreeing, and for the clarity of culture items (5.0) (Figure 6).

Regarding the aggregated evaluation, the mean highest relevance was obtained for the leisure field (4.6), with the greatest degree of agreement (variance 0.5). The mean highest importance is the relationship with nature field, with the best evaluation (4.5) and degree of agreement (variance 0.8). Finally, the mean highest clarity (4.7) and the greatest degree of agreement (0.7) is the leisure field (Figure 6).

In the second query, the evaluations and comments in the answers were added together, and the questions were reformulated to produce the final survey for the study.

In Question 6, which had a variance in the clarity of the question of 3.12, it was specified as “Is it accessible to anyone?” to make it clearer.

Question 10 was not included, as the experts’ observations showed they considered it to be very open, with a variance in clarity of 2.24.

A final question related to socioeconomic aspects was included in the final design of the survey.

Thanks to the Delphi methodology used by the panel of experts, the survey was ready in 2021, and two waves were launched with a good number of responses. Two more waves were carried out to reinforce the responses with direct interviews in the population segments that were less represented in the online responses.

4. Discussion

Recent studies show that a physical connection to nature improves human cognition and social skills and physical, psychological and mental health. They also reveal that a psychological connection with nature has a positive impact on sustainable behaviours and values, as well as improving mental and physical health [49]. Participation in simple nature-related activities also contributes significantly to nature conservation and sustainable behaviour [50]. Studies have identified the relationship between connection to nature, concern for the environment and sustainable attitudes. This is why this research is so important for designing a questionnaire to establish the relationship between outdoor activities and connection with nature and its impact on human well-being for a sustainable life, according to peoples’ socioeconomic profiles.

There is a lack of information on other types of activities and connection with nature, so the questionnaire proposed by the experts is highly relevant at this time. As it is designed to be answered by people in any country without regard to gender or social status, knowledge of the issue can be obtained on a global level.

More than half the questions on the proposed questionnaire concern contact with nature. The experts’ average score for the relevance of the items points to the conclusion that health and leisure questions are the most important reasons for outdoor activities and for assessing the positive perception of nature. Sustainable behaviour and culture are also relevant.

The least variability in the relevance of the questions is found in the leisure items, followed by contact with nature and health. The importance assigned by the expert group to the issues is equal on average for all the topics, except for the items related to culture, which are slightly lower.

The use of the Delphi method is recommended for studies with little prior empirical evidence [51]. The Delphi method is a structured communication technique frequently employed in research to gather expert opinions and achieve a consensus on specific topics [52]. It is widely applied across various fields, including health sciences, ecology and information systems, due to its ability to handle complex issues and reduce ambiguity through expert input [53].

The Delphi method is effective in reaching a consensus among experts by using multiple rounds of questionnaires, which allows for refinement based on feedback. This iterative process helps develop reliable and valid questionnaires. The method’s anonymous nature encourages candid feedback and reduces the influence of dominant individuals, while allowing more inclusive participation [54]. The method has been approved for the design and validation of a new questionnaire to provide a suitable tool for future studies.

The Delphi method has recently been used with good results for the validation of questionnaires related to the psychological connection with nature [55]. However, it does have some limitations: it can introduce representativeness biases if the selection of experts is not carried out with care and attention; the two rounds for the iterative feedback and analysis require time; the reporting quality is crucial; and the attrition and participation rates must be considered when assessing the reliability of results [53,56].

The literature proposes a panel size between 8 and 23 experts from the different stakeholder groups involved in the study [57]. Eighteen experts were selected on the basis of their professional experience [58] and not for their scientific output, unlike in other works [59]. The composition of the expert panel determines the results of the research technique applied [60], and the panel must be representative and have years of experience. In this case, professionals with a high degree of experience and from diverse and complementary fields were chosen to represent the group of people who carry out activities in nature: practitioners of sports such as hiking or skiing, environmental managers, health personnel, etc. The results of the three groups of experts were similar, with environmental managers giving the lowest scores for all items and with the greatest variability. The leisure experts responded very similarly to the well-being experts, except for the questions related to culture and sustainable behaviour, which the leisure experts rated more highly.

Compared to the results shown in [51], the means obtained for the different aspects of the items are similar and, although the variability is a little higher, the standard deviation is less than 1.5 [61]. All item groups had mean scores above 3.5 for relevance and importance and low variability. Questions 6 and 11 showed high variability in terms of their clarity, so it was decided to include some clarification to the words’ accessibility and satisfaction to make them more easily assessable by the respondent.

The expert assessment using the Delphi method is therefore suitable for the design and evaluation of the questionnaire, thus verifying the validity of the content and ensuring the validity of the construct [58] by clearly defining the objective to be evaluated and the appropriateness of the questions. The method represents a valuable instrument for achieving expert consensus across a range of research domains [62].

Other research techniques such as focus groups supported by multi-method material or the use of neuroscience could be complementary in the specific population. However, the cost of research is much higher, and it is beyond the scope of this paper.

Leisure patterns changed during the COVID-19 pandemic [63], from people participating in more home-based leisure to outdoor leisure between the two waves. It was also found that participating in more outdoor leisure activities contributes to greater well-being [64,65]. By having their outings reduced to only essential activities, city dwellers realised that they wanted green spaces of different sizes within the fabric of cities to allow them to exercise and relax and enjoy the outdoors, contact with nature and relationships with other people [66].

Studies related to nature and well-being are numerous since COVID-19, but there are research gaps [67], such as the identification and analysis of health-promoting sustainable behaviours other than physical activity or the mechanisms underlying the heterogeneity in the nature–health relationship based on human, natural and geographical characteristics. The future of humanity requires adapting individual and organisational behaviour to be environmentally sustainable. This could be evidenced with the questionnaire that is the subject of this work.

The practical implications of the results of this work are a set of recommendations for decision makers in public health, urban planning and education and for raising public awareness of the benefits of the natural environment. These recommendations include improving green infrastructure [68], promoting outdoor activities in contact with nature to improve well-being [69] and ensuring equitable access to parks and natural areas for all communities [70].

For the future, the remote participation of experts in the Delphi method makes it a practical choice for a global study. Future research endeavours could concentrate on methodological enhancements, integration with quantitative methods and leveraging technology to enhance the efficiency and effectiveness of Delphi studies. These efforts could expand the method’s utility and address current challenges in its application [52,53,62].

5. Conclusions

The application of the Delphi methodology has been useful for configuring the survey as a tool to assess how outdoor activities in contact with nature influence people’s well-being. Most of the items stated by the group correspond to questions about activities in contact with nature. The average score given by the experts to the relevance of the items leads to the conclusion that questions about health and leisure are the most important reasons for outdoor activities and for assessing the positive perception of nature. Behaviour and culture are also relevant. The experts contributed key aspects to the development of the survey, namely the importance of the questions included for the object of the study, the length of the questionnaire, its wording to ensure it is easily understood by the respondents, and its attractiveness, to avoid participants abandoning it during the completion process.

The survey was designed using the Delphi method, with the participation of 18 experts in the field of the natural environment, well-being and leisure. This allowed the integration of the different visions of the complex reality of the natural environment. The composition of the panel of experts determines the results of the research technique applied. The panel managed to converge on the selected questions in two rounds. Only one question on the questionnaire had to be reformulated, and one question was eliminated due to the comments of a majority of the experts. An improvement in the quality of the research is expected as a result of these questionnaires.

The online survey contributes to facilitating the process (data collection, dissemination and subsequent processing) and reducing the overall associated cost. Other research techniques such as focus groups with the support of multimedia material or the use of neuroscience could be complementary methods in the specific population; however, this would increase the cost of the research and is beyond the scope of this study.

As this questionnaire has a large number of questions, the number of responses obtained indicates that the problem is of interest to people and that the time seems right to consider an in-depth study of these issues. Finally, COVID-19 reinforces the interest in this area of research.

In the future, the Delphi method could be employed in collaboration with experts from various locations using remote technology for global research, with a focus on enhancing the iterative process, expert engagement and leveraging technology to improve the quality of Delphi studies. These endeavours could enhance the utility of the method and address current challenges.