Introduction
Wetlands and aquatic ecosystems represent invaluable national and international assets that necessitate rigorous conservation, particularly from an environmental perspective. Often compared to rainforests in terms of ecological significance, wetlands rank among the world’s most productive ecosystems, harbor immense biodiversity, and cover approximately 6% of the Earth’s surface. Beyond their ecological roles, they constitute a priceless heritage due to their substantial economic, cultural, scientific, and recreational potential. The Hamun Wetland, the largest of its kind in eastern Iran, is no exception; throughout its lifecycle, it has undergone profound transformations.
The degradation of biodiversity within the Hamun Wetlands disrupts their ecological functions, inevitably leading to a decline in both the quantity and quality of ecosystem services provided to society. Such hazards impose deleterious effects on human settlements, inflicting widespread economic, social, and environmental damage while accelerating desertification processes. Consequently, mobile sands (shifting dunes) represent a critical natural hazard, posing a significant threat to human communities.
Under these circumstances, the restoration of the Hamun Wetland transcends being a mere environmental option; it is a strategic imperative for achieving sustainable development and ensuring regional socio-economic stability. This paper focuses on the vital necessity of restoring the Hamun Wetland, exploring its significance through two interconnected lenses: the economic and the environmental. From an environmental perspective, restoration ensures the recovery of critical ecosystem services, such as natural water purification, soil stabilization, dust mitigation, and the preservation of regional and global genetic diversity. The primary objective of this study is to provide an analytical framework—grounded in the latest scientific evidence and techno-economic assessment models—to examine the impacts of the Hamun International Wetland’s desiccation on the livelihoods of Sistan’s inhabitants, assess their willingness to participate in conservation and restoration efforts, and evaluate the potential for the repatriation of displaced populations to their ancestral lands.
Methodology
The Contingent Valuation Method (CVM) constructs a hypothetical market for environmental goods or services, utilizing survey-based questionnaires to elicit individuals’ willingness to pay (WTP) for changes in the provision or quality of such goods. The primary objective of this method is to derive a precise estimation of the benefits stemming from alterations in the supply level or pricing of non-market public goods and services. Within economic theory, changes in consumer welfare are quantified by estimating compensating and equivalent variations, which serve as indicators of WTP for specific goods. This is typically operationalized using double-dichotomous choice questionnaire data, wherein respondents are presented with a binary choice—‘yes’ or ‘no’—to a proposed monetary value. Furthermore, Logit, Tobit, and Probit models are employed to estimate regression functions with binary dependent variables; research consistently indicates that the results derived from these models do not exhibit statistically significant differences.
In this study, a double-dichotomous choice (DDC) questionnaire was designed to conduct interviews and elicit the WTP of individuals for the conservation of the Hamun Wetland. This ensured that respondents were provided with accurate and sufficient information to fully comprehend the hypothetical market scenario. The questionnaire consisted of two sections: the first section captured the socio-economic profile of the respondents, including variables such as occupation, education level, household size, income, and various other demographic characteristics. The sample size of 385 participants was determined using the Cochran formula, based on data derived from 74 pilot questionnaires.
Results
The Likelihood Ratio (LR) statistic in the Sistan region was found to be 33.77. Since this value exceeds the provided p-value, the overall estimated model is statistically significant at the 1% level. For the estimated Logit model, a McFadden’s pseudo-R^2 value of 40% is considered highly satisfactory, given the number of observations of the dependent variable. The estimation results of the Logit model indicate that the coefficients for the explanatory variables—gender, net income, bid amount, and overall attitude—are significant at the 5% level. The mean household size was 3.5, and the average annual payment per household for the wetland conservation was 17,047.87 Rials. Overall, the findings suggest that the economic status of the community may exert a positive influence on the regional environment and the level of participation in the conservation and maintenance of these resources. However, it should be noted that this study focuses on the socio-economic impacts on the preservation and restoration of the Hamun Wetland and does not account for diplomatic considerations. There remains a critical need for governmental intervention to secure water rights; only through such measures can comprehensive wetland conservation efforts be realized. If these actions are implemented, the livelihoods of the local population will be revitalized through restored water flows in the wetland, and the problem of dust storms will be substantially mitigated.
Discussion and Conclusion
The estimated coefficient for the ‘bid amount’ variable in the Sistan region was found to be negative, indicating that under the hypothetical market scenario, an increase in the proposed bid amount leads to a decrease in the probability of a ‘yes’ response regarding willingness to pay (WTP). Based on the marginal effect analysis, a 10,000 Rial increase in the proposed bid reduces the probability of accepting the payment for wetland conservation by 24.3%. Conversely, the coefficient for the ‘income’ variable is positive, suggesting that an increase in individual income enhances the probability of WTP for wetland protection. Specifically, for every one million Rial increase in income, the probability of accepting these payments increases by 2.22%. The positive coefficient for the ‘overall environmental attitude’ variable indicates that individuals with more positive environmental attitudes exhibit a higher propensity to pay; the marginal effect shows that an increase in this variable leads to a 3.5% increase in the probability of accepting the proposed amounts. Furthermore, the positive coefficient for the ‘level of familiarity with the Hamun Wetland’ suggests that individuals with greater familiarity are more likely to respond affirmatively. Higher levels of public awareness and cognition regarding the Hamun Wetland increase the probability of WTP by 33%. Finally, the positive coefficient for the ‘number of wetland visits’ reflects the community’s interest in and perceived importance of the environment; an increase in the frequency of visits to the Hamun Wetland is associated with a 14% increase in the probability of willingness to pay.