چكيده لاتين :
Wetlands are among the Earthʹs most productive ecosystems, with high biological productivity and richness. In addition to ecological values, wetland systems directly support millions of people and provide goods and services to the adjacent areas.
Anzali International Wetland, located in Gilan province in north of Iran, has always been recognized as one of the major sources of drinking water for the adjacent inhabitants and provided them with food and many other services. Historical relationship between the wetland and local people has resulted in a special way of life so that the wetland has always been a part of identity and domestic culture of the area.
Unfortunately in recent years, population growth and consequences of several developments in the area has resulted in high pressure on the wetlandʹs natural resources which are exploited rapidly in an unsustainable and unsupervised manner. Human activities such as industrial and urban development, introducing exotic species, and specially road construction has resulted in contamination of rivers in the wetlandʹs basin and rapid changes in land use of adjacent areas which destroyed the balance of the wetland and changed it drastically so that it will dry very much faster than its natural succession.
Itʹs important to help decision makers understand that beside economic benefits from developments in areas such as Anzali wetland, important environmental values are irreversibly destroyed. So changing such values to monetary figures may be a good strategy to make it clear that environmental values are not priceless. So environmental economic can serve environmentalist as a tool to get to this aim, which is carried out by valuation techniques. These techniques can provide useful evidence to support such policies by quantifying the economic value associated with the protection of biological resources.
Environmental valuation can be defined as the attempt to assign quantitative and monetary values to goods and services provided by environmental resources or systems, whether or not market prices are available to assist us. In this research, it is attempt to quantify a part of Anzali wetlandʹs environmental values as a precious and unique ecosystem that should be preserved for the future generation.
Anzali International Wetland is a coastal liman, or lagoon, in the Caspian Sea near Bandar-e Anzali, in the northern Iranian province of Gilan. Although its total area is around 193km2 It was partially registered (150km2) as a Ramsar site in June 1975 in accordance with the Convention on Wetlands of International Importance. However, due to a range of influences related to human activity, the water quality of the Wetland deteriorated and, as a result, in 1993 Anzali Wetland was designate as a wetland on the Montreux Record. Because the non- use values of wetlands are usually overlooked and less integrated into decision makings, in this research, it was attempted to estimate and introduce this type of Anzali wetlandʹs values. For this purpose, contingent valuation (CVM) method was used to determine the wetlandʹs existence, option and bequest values by means of assessing public opinion through a questionnaire.
The statistical survey has been carried out by use of internet. The questionnaires were sent to members of 10 general Persian mail groups in Yahoo which consisted of 3000 email addresses, among which 102 questionnaires were answered and turned back that is equal to 3.4 % from the total mailed questionnaires. Contingent valuation (CV) has been used to reveal preferences for environmental goods that are not directly observable from market transactions. The contingent valuation method (CVM) is a stated preference method for valuing changes in the provision of nonmarketable goods (e.g. environmental amenities). Basically, CVM is a survey-based methodology which relies on obtaining monetary estimates for the economic value of a specified change in the provision of the environmental good of interest, which typically is not traded in the conventional markets. CVM consists in the construction of hypothetical markets (also called elicitation scenarios) where the individualsʹ valuation of the good is elicited. Monetary estimates are obtained either as individualsʹ Willingness to Pay (WTP) or Willingness to Accept (WTA). WTP measures the amount of income a person is willing to forego in exchange for an improved state of an environmental good.
The Willingness to Pay (WTP) was calculated by use of econometrics methods and Eviews software which uses a Logic model. The results of the model are shown in the following table.
Table 1: Results of Logic model used for Anzali Wetland Valuation
Variable Coefficient t-value Significance
Constant 1.03653700 5.280672 0.0000
Bid 0.00000924 2.948499 0.0032
Education -0.02388500 -1.702914 0.0886
Income 0.00000018 0.891433 0.3727
Log likelihood: -65.29070
Mean dependent var: 0.843137
S.E. of regression: 0.356283n
Sum squared resid: 12.31297
Total obs:102
75000 ,
f --7 = 8803.92 Rials =0.9 US$
0J 1 + exp{- (intrecpt - pX)}
Above equation shows the expected value of truncated mean WTP, which represents the existence value of the Anzali Wetland. It was calculated by numerical integration, ranging from 0 to maximum bid after parameters from Logic models were estimated using the ML method. The socioeconomic term of h was estimated and added to an adjusted intercept together with the original intercept term ofa .
Because the offered prices have been for an unlimited duration of time and presently paid, the respondents have considered discount rate in their minds. According to the results, the mean WTP for existence value of Anzali Wetland was calculated 8803.92 Rials yearly.
In this research, the existence value of Anzali Wetland for people was calculated according to their Willingness to Pay in a hypothetical market in which the benefits would be non-use ones. The results of this research indicates that despite Iran being a developing country with medium to low income levels, the evidence suggested that people are willing to pay for preserving environmental amenities. This supports the idea of Amirnejad, et al. who calculated the existence value of North Forests of Iran.
This research indicates that by raising the offered price, the respondents show more willingness to pay for preservation of Anzali Wetland. This may be because of the following reasons:
Firstly, estimation of Willingness to Pay is done for an unlimited period of time whereas in other researches, it has been calculated for a year or a month.
Also it seems that in Iranian culture, lower price has an impression of being worthless, so the respondents show more willingness to pay by raising the offered prices.
This research also indicates a negative relationship between years of education and respondentsʹ willingness to pay, which can be due to having less time for visiting the site and also lack of environmental attitude in educated people of Iran.
At last, there is a positive relation between the respondentʹs level of income and the wetlandʹs value for them, which can be due to the absence of economic pressures and many other socio- economic factors related to economic welfare.
However, the measurement of monetary values associated with environmental benefits can be very difficult, especially in the case of little known resources, such as biodiversity. Besides the limitations in existing knowledge about the association between ecological functions and economic benefits, there are fundamental methodological limitations. The underlying assumption is that people are able to translate a wide range of environmental criteria into a single monetary amount representing the total value to them of a particular resource, which is not true for all of the respondents.
While ecosystem valuation is certainly difficult, it has become essential for the decision-makers who face the tradeoffs among different functions of ecosystems on the one hand and the competing demand on the resources at their disposal, on the other. This is very important and vital for Anzali Wetland because the decision makers have to face the tradeoffs between the competing demands of developments in the wetland basin and on the other hand, preserving it as a valuable asset for the future generation so it is necessary to undergo more comprehensive studies to estimate the Total economic values of the wetland and hand over the results to the decision makers as different alternatives to compare the development and preservation scenarios. It is important to note that preserving the wetland and its related values is not achievable by setting a protected buffer and it is necessary to run the investigation in its whole basin.
