1. Introduction
Throughout history, humans’ relation with water has been very important, and with population growth and urbanization, the demand for water resources has increased [
1]. Over the last decades, some regions have encountered severe drought that influenced water supply security [
2]. Water crises affect many parts of the world and by 2050, more than 40% of the world population is expected to be living in water-stressed regions [
1]. Turkey is one of those water-stressed regions. Because of overpopulation and the overconsumption of water for irrigation purposes, the pressure on water resources has increased in Turkey [
1]. Furthermore, because of climate change, the water cycle has been broken, and while this problem caused floods in some places, it caused drought in other places [
1]. Because of overpopulation, urbanization and industrialization, water pollution has increased and clean water resources have decreased. Based on the Intergovernmental Panel on Climate Change (IPCC) report [
3], because of climate change, water scarcity will increase in many regions of Turkey. With the increase in temperatures and the decrease in the amount of precipitation, barren areas will increase in Turkey [
4]. Water management is not only important for agriculture and industry, but it is also important for sustainability of the ecosystems [
1]. The city of Ağrı, where this study was conducted, is located in the east border of Turkey. This city is famous for its long and harsh winters. Agriculture and animal husbandry are the most important sources of livelihood in the city. A large river passes through the middle of the city. Although there are water supplies such as rivers, streams and lakes, the problem in this region is the insufficient water management strategies because of financial problems and lack of awareness of water conservation in the society. Water pollution is an important problem. Insufficiency of the water treatment system and lack of environmental awareness of people cause water pollution in the rivers, lakes and streams in the city [
5].
As mentioned above, the study area has several environmental problems and people are not aware of these problems. Therefore, this study is important to develop the sustainable water consumption behaviors (SWCB) of pre-service teachers as they will be role model to the society in the future.
To achieve SWCB, it is necessary to increase water supply through desalinization and recycling waste water, to reduce water demand, and to conserve water resources [
6]. In addition to sustainable water management strategies, it is essential that individuals’ SWCB should be increased [
7]. Moreover, understanding the factors leading to SWCB such as environmental attitudes, values and beliefs can improve water management strategies, policy development and education [
8,
9].
Education for sustainable development (ESD) is a key strategy to increase public awareness and training related to sustainability and to empower everyone to make informed decisions regarding sustainability issues [
10,
11]. ESD focuses on major social, economic and environmental problems [
10]. ESD can be provided in all levels of education from early childhood to higher education and improves knowledge, skills, attitudes and values to contribute to sustainability [
12,
13]. According to Chawla [
14], environmental characteristics that influence pro-environmental behaviors are shaped by several factors which are childhood experiences in nature, pro-environmental values held by the family, pro-environmental organizations, role models (friends and teachers) and education. Teachers touch millions of people’s life and shape their worldviews, values and attitudes and help individuals to take actions for the environment [
10]. Teachers have a significant role in bringing major changes in society and creating a sustainable future [
15]. The first goal of ESD is to provide quality basic education. Therefore, teacher availability and teacher quality are important in ESD [
10]. The second goal of ESD is to reorient education programs to address sustainability principles [
10,
11]. In other words, there is a need to reorient teacher education programs to reach the sustainability goals. At this point, teacher education for ESD is important to shape future generations’ worldviews, attitudes and abilities for a sustainable future [
11]. There is a need to develop teachers’ knowledge, skills, attitudes, behaviors and values for sustainability issues [
10]. Moreover, teachers should be equipped with necessary competencies related to ESD (e.g., knowledge, emotions, values and ethics and action) [
16]. Future teachers should also have the necessary values, beliefs, awareness and responsibility to take action for sustainability [
17,
18]. For this reason, factors such as beliefs, attitudes, and values have an influence to shape individuals’ sustainable behaviors. That is to say, these socio-psychological factors play an important role in promoting environmentally responsible behaviors [
19]. As the literature reveals, only attitude and knowledge variables are not effective to explain sustainable behaviors (e.g., [
20,
21]). More knowledge on and improved attitudes toward environment do not always lead to behavior change. Other factors such as beliefs, values and norms should also be addressed to understand sustainable behaviors [
19].
The Value-Belief-Norm theory (VBN), which constituted the framework of this study, is one of the most important theories that explain environmental decision making and pro-environmental behaviors [
19]. VBN focuses on values, beliefs and personal norms (PN) and it is accepted as a value theory [
22,
23]. Therefore, VBN is a useful theory to explain sustainable behaviors [
19]. More specifically, the current study examines pre-service teachers’ SWCB through the application of the VBN theory. In the literature, there is a considerable number of studies investigating the energy conservation, eco-friendly and sustainable behaviors of different samples such as college students, customers and teacher candidates (e.g., [
17,
19,
24,
25]). However, not many studies have yet focused on the SWCB through socio-psychological factors. For this reason, in this study, we explore factors affecting SWCB by using VBN theory.
2. Theoretical Approach: VBN Theory
The VBN theory proposed by Stern, Dietz, Abel, Guagnano and Kalof [
26] forms a link among the values theory (e.g., [
22,
23]), the norm activation theory and the beliefs. The VBN theory connects these three constructs through a causal chain of five variables that are values (biospheric, altruistic and egoistic), environmental beliefs, PN for pro-environmental behaviors and environmental behaviors. [
26]. Within environmental beliefs awareness of consequences (AC) and ascription of responsibility (AR) are considered [
17,
25,
26]. Specific to this current study,
Table 1 shows the variables and definitions based on the VBN theory. According to Stern and his colleagues [
26], each variable in the chain is related to each other and is directly linked with the next variable. The authors suggest that environmental behaviors result from PN, such as feeling moral obligation to act for the environment, and these norms are activated through environmental beliefs (AR and AC beliefs). AC beliefs refer to being aware of the consequences of the environmental threats and AR beliefs refer to the sense of responsibility to act for reducing these threats [
26,
27]. Steg et al. [
25] pointed out that AC and AR beliefs could be behavior-specific. In this study, AR and
AC beliefs were considered within the beliefs related to water consumption behaviors. Based on the VBN theory, AR and AC beliefs are also dependent on general beliefs on human-environment relationship and value orientations [
26]. Therefore, beliefs are highly significant in the VBN theory as they directly influence norms, and indirectly and directly influence environmental behaviors [
28].
Another VBN factor utilized in this study is values. Stern, Dietz and Kalof [
29] described values as biospheric value orientation (BV), feeling concern for non-human species and the biosphere; altruistic value orientation (AV), reflecting concern for the welfare of other people; and egoistic value orientation (EV), feeling concern for the environment for their own sake. According to the
VBN theory, values are associated with each variable (AC, AR, PN and pro-environmental behavior) in the chain [
29]. For example, in order to change the current norms, individuals’ biospheric value orientation (BV) sho-uld be fostered first [
19]. PN as another factor in the VBN theory was developed to predict humans’ target behavior based on the norm activation theory [
30]. The theory indicates that pro-environmental behaviors can occur when people feel a moral obligation to perform the behaviors and when they realize the adverse consequences of their actions for the environment (AR and AC beliefs) [
17,
25,
31].
The VBN theory has been widely used to explain the relationship between the socio-psychological factors and pro-environmental behavior and has been applied to various populations. For instance, it has been used to understand energy conservation behaviors (e.g., [
17,
25,
32,
33]), customers’ eco-friendly behaviors (e.g., [
24,
34,
35]) and university students’ sustainable behaviors such as food and energy consumption and transportation choices (e.g., [
19]). In these studies, the VBN theory was tested to reveal what predictor variables (values, beliefs, attitudes and PN) explain pro-environmental behaviors. On the other hand, water conservation behaviors have been studied within different disciplines such as psychology, sociology, political science and economics [
36].
In the literature, various psychological determinants such as attitudes, beliefs, PN, environmental values, environmental concern, self-efficacy and motivation have been studied in order to predict water conservation behaviors (e.g., [
7,
36,
37,
38,
39,
40,
41,
42]). Kang et al. [
38] examined consumers’ SWCB by creating a model examining how water beliefs (e.g., utilitarian water belief, ecological water belief) affect attitude, subjective norm, perceived control and moral obligation related to water consumption and how they respectively affect SWCB. The authors have not tested the VBN theory yet. They developed a comprehensive model to explain water consumption behaviors. They explored the significant effects of utilitarian water belief, ecological water belief and water resource concern on consumers’ perceptions and SWCB. In another study, Schultz and his colleagues [
37] examined the impact of norm-based messages on the water consumption behaviors of residents. The authors measured residents’ environmental beliefs, attitudes, conservation behavior, personal values and personal water conservation norms. They found that normative messages might have an impact to reduce water consumption and that the residents holding strong PN about SWCB were influenced less by normative messages than the residents with low PN.
The studies in the literature showed that the VBN theory is successful in explaining various pro-environmental behaviors; however, there are not enough studies to explain SWCB through the VBN theory. Thus, the current study contributes to the literature in several ways. First, based on the literature mentioned above, we constructed a theoretical model, which is shown in
Figure 1. We tested this model using the structural equation modeling (SEM) analysis. Then, we conducted mediation analysis with the bootstrapping method. In this way, the relationships in the model were better understood. Most researchers addressed the indirect effect on specific pro-environmental behaviors through mediation of the variables in the VBN model [
25,
43,
44]. Therefore, we investigated meditation analysis among variables, since several researchers reported that values and behaviors might be mediated by other factors like beliefs and PN [
25,
44]. In line with the literature review, we tested the mediation effect on SWCB.
Based on the model, we hypothesized that:
BV and AV have a positive impact on AC.
EV has a negative impact on AC.
BV and AV have a positive impact on PN.
EV has a negative impact on PN.
BV and AV have a positive impact on SWCB.
EV has a negative impact on SWCB.
AC has a positive impact on AR.
AR has a positive impact on PN.
PN has a positive impact on SWCB.
The mediation effects among variables:
AR indirectly influences SWCB through PN.
AC indirectly influences PN through AR.
AC indirectly influences SWCB through PN and AR.
Values indirectly influence AC through AR.
Values indirectly influence SWCB through PN.
Values indirectly influence SWCB through AC, AR and PN.
5. Discussion and Conclusions
The results of this study have both theoretical and practical importance. In the literature, the VBN theory has mostly been used to predict general pro-environmental behaviors (e.g., [
24,
34,
35,
43]), specifically energy conservation behaviors (e.g., [
17,
25,
32,
33]), and college students’ sustainability behaviors (e.g., [
19]). However, there is a lack of studies predicting SWCB of pre-service teachers using the VBN theory. Theoretically, this study focused on Turkish pre-service teachers’ SWCB by testing the VBN theory.
According to the descriptive results, the pre-service teachers were aware of the consequences of their actions on water resources and they accept responsibility towards unsustainable water consumption. They also had a sense of moral responsibility to save water. Moreover, they held higher BV and AV than EV. The reason for high scores in these socio-psychological factors may be the environmental consciousness of participants, which can be attained through mass media, and environmental and sustainability education courses. Environmental and sustainability education courses have recently been involved in the teacher education programs in Turkey (e.g., [
53,
54]). Therefore, pre-service teachers are required to take these courses.
However, it was found that the pre-service teachers in the current study had a low level of SWCB, although they had positive beliefs and values. The reason behind this result can be socio-economic factors as these participants are studying in a rural city and they come from the rural cities in the east of Turkey. More than half of the participants’ family income is minimum wages, and most of them had parents with low level of education. Family education is important since most of the pro-environmental behaviors are shaped in the family [
14]. Therefore, one of the reasons for showing low SWCB can be family education in the current study.
There are also other factors that influence especially water conservation behaviors (e.g., [
36]). These factors can be water prices, family income, age, education and household size. In the literature, there are different results about these determinants. For example, several researchers explored that higher income homes consume more water than lower income homes (e.g., [
55,
56]). According to some researchers, well-educated people consume more water than less educated people (e.g., [
57,
58]). In this study, the socio-economic status of the pre-service teachers is not high. Therefore, apart from these socio-economic factors, there might be other factors that influence the pre-service teachers’ water consumption behaviors in this study. These factors could be water prices and location. Water and waste water prices for citizens living in the east of Turkey are a little cheaper compared to other cities in the west (e.g., [
59]). Corral-Verdigo et al. [
60] pointed out that water prices are significantly related to water consumption behaviors. Several studies also (e.g., [
61,
62]) argued that an increase in water prices decreases water use of people. On the other hand, some studies (e.g., [
63,
64]) pointed out that demand for water use is poorly sensitive to water price. As Carter and Milon [
65] emphasized, increasing water prices may not influence sustainable water use; however, it may help increase the awareness of people about their amount of water use. Water price is a debatable issue. Therefore, the relationship between water prices and water consumption behaviors can be investigated in the future studies.
Based on the SEM analysis in the current study, the relationship between PN and SWCB was found to be quite high. Similar results were found in the literature (e.g., [
40,
66]), and PN was accepted as an inner motivator. That is, when people hold a strong PN for water conservation, they display the behavior even if other people do not display the behavior [
37,
67]. Similarly, Corral-Verdugo and Frias-Armenta [
40] conducted a study with Mexican residents and they found that there was a positive relationship between PN and water conservation behaviors. In this sense, there is a need to establish PN which can be improved through environmental and sustainability education [
68].
Concerning the results related to values, it was found that EV was not related to AC, AR, PN and SWCB. Some studies showed a significant and negative relationship between EV and pro-environmental behaviors (e.g., [
17,
43]). Aprile and Fiorillo [
36] explored that EV and AV are the positive drivers of water conservation behavior. However, in the current study, it was indicated that having EV such as authority, social power and wealth had no influence on SWCB. On the other hand, it was explored that BAV had a significant and positive relationship with SWCB. In this study, the pre-service teachers’ mean scores for AV and BV were higher than their EV. That is to say, they seemed to attribute a higher value to the impact of environmental problems on other people and non-human beings. Moreover, in this study, the BV and AV were clustered. Several researchers also pointed to the combination of BV and AV (e.g., [
28,
52]).
Some empirical studies supported that individuals who have BV and AV tend to show more pro-environmental behaviors [
17,
36,
43,
69]. In the current study, it was explored that BAV is indirectly related to SWCB through beliefs (AC, AR) and PN. Stern and Dietz [
52] described that values can be directly or indirectly related to pro-environmental behaviors through beliefs. In this sense, this study supported the indirect relationship between BAV and SWCB. It means that the pre-service teachers who give importance to social justice, equality and world peace (AV) and who respect earth protect environment (BV) and are aware of the impact of their actions on water resources. Thus, they take the responsibility in terms of water consumption problems. They also have a higher level of moral obligation to behave sustainably and they tend to show more SWCB. This result is slightly different from other studies (e.g., [
43]). Liu et al. [
43] found that AV has a significant positive influence on the pro-environmental behaviors, while BV does not have a positive significant relationship with pro-environmental behaviors. On the other hand, in their study, EV was found to have a negative significant influence on the pro-environmental behaviors. In another study, Şahin [
17] found that BV orientation made the highest contribution to the explanation of energy conservation behavior of pre-service teachers. In our study, a direct relationship with any type of values was not found. The reason may be related to the context. Liu et al. [
43] explored pro-environmental behavior as a general manner, and Şahin [
17] explored the energy conservation behavior. In the context of sustainable water consumption in our study, values contributed to the model indirectly. However, future studies with different samples from various different universities located in different regions are needed to generalize this finding.
Lastly, in this study, mediational effects were investigated and the results revealed that the model for SWCB was supported with the VBN theory. The results suggest that BAV leads to increased awareness of the consequences of water conservation and a greater sense of responsibility for sustainable water use. Furthermore, an increased sense of responsibility leads to an increase in PN for sustainable water use, which in turn leads to an improved SWCB. These results are in parallel with those of several previous studies conducted on various environmental behaviors [
19,
25,
43,
44,
70,
71] explained the willingness to reduce car use with the VBN theory, and the mediation analysis showed that the causal chain model worked for the model. This mediation results suggest that sustainable water use behavior is complex in nature and a number of variables affect this behavior directly and indirectly. Considering this result, environmental education practices focusing on water conservation should aim to improve BAV, awareness of the consequences of wasteful water use, sense of responsibility for sustainable water use, and personal moral obligation for water conservation. In this way, SWCB can be improved among pre-service teachers.
As a result, this study revealed that the VBN theory was successful in explaining the SWCB of the pre-service teachers. The results give educators, researchers and policy makers some insights to develop pre-service teachers’ SWCB, while considering values, PN, beliefs and attitudes. In Turkey, the elementary science education curriculum has recently been changed and now it includes some objectives related to sustainable development [
53]. However, these objectives are limited to objectives regarding the use of natural resources sustainably and especially supporting recycling practices [
53]. However, water issue is not sufficiently covered in the curriculum. In the curriculum, there are only objectives related how the water cycle works and there are no explanations about the impact of climate change on water resources and how to conserve water supplies [
53]. These issues should be covered in the curriculum in detail. There should be environmental and sustainability courses in the elementary education. Students should even take these courses from early childhood to higher education. There is a need to increase the awareness of students related to sustainable water consumption and to develop their SWCB. Pre-service teachers are the key agents to shape future students’ awareness, values, attitudes, beliefs and behaviors related to water conservation. For this reason, the number of environmental and sustainability education courses should be increased in teacher education programs to influence the SWCB of pre-service teachers positively.
The limitation of this study is that the data were collected in one university located in the east of Turkey. Therefore, it may not be generalized to other regions. Therefore, there is a need to conduct this study with pre-service teachers from different disciplines in higher education and more samples from different regions of Turkey. Moreover, this study can be conducted with elementary school teachers to explore their values, beliefs, norms and behaviors related water consumption. It is necessary to conduct more studies within the context of sustainable water consumption to produce additional theoretical and practical results.