عنوان مقاله [English]
Experts monitor and value the flow of goods and services produced by wetlands, some of which are traded in markets. Many other goods and services are not marketed, but economists have developed techniques to estimate the economic value of goods and services, which have complex economic and biological relationships. Market goods and services provide personal benefits, while nonmarket goods and services primarily benefit society. To estimate these values, economists have developed methods for valuing nonmarket goods. However, differences in methods, physical characteristics, and location of wetlands in the socio-economic landscape and background contribute to further differences in wetland value. This study aims to identify the type of wetland and the functions of the Qarah Qeshlaq wetland index to enable sustainable development and operation of the wetland through zoning and to determine the value and supply of ecosystem services through planning and management of the wetland. This indicates that ecological resources of this region should be allocated to intrinsic functions with a total net benefit measured by assessing the economic benefits of each usage minus the costs. Ultimately, these services and benefits are assigned to the community.
Materials and methods
The study area of the Qarah Qeshlaq wetland (22,000 ha) is located between the provinces of East and West Azerbaijan and on the edge of Bonab and Miandoab cities (37° 13' 25" N, 45° 51' 38" E). On the other hand, it is situated on the southern shore of Lake Urmia at an elevation of 1270 m above sea level (Fig. 1). This wetland includes part of the estuary of the Zarrineh Rud, Sufi Chai, Mordagh Chai, Lilan Chay, and Haji Mosayeb Chai rivers, as well as Neor Chai, which varies in proportion to the peak discharge of the above-mentioned rivers.
InVEST3.7.0 is free software available under open source license. Updated versions of the tool are released approximately every three months, which include updated science or new models. First, the main InVEST models were created in ArcGIS. But now almost all models are executable in an independent form and there is no dependence on other software.
This model was developed to study the fish production and their economic value in an area. Water temperature and aquaculture conditions are the main factors considered. This model provides the most accurate results using on-site temperature parameters and aquaculture operations as inputs. The model was implemented in four steps:
1) Modeling from growth stage to exploitation of aquatic species;
2) Calculating the total weight of fish produced by multiplying the number by the weight of the fish, thus eliminating the fish with lower weight and those eliminated due to natural mortality;
3) Harvesting all fish on the farm at the same time and restarting the farm after a user-defined downturn; and
4) Assessing the processed harvest as an optional and final step of the model.
This study has used a conditional valuation method to value the indirect services of the Qarah Qeshlaq wetland. A questionnaire was used to determine people's willingness to pay under hypothetical market scenarios. We used a logit regression model to examine the effects of different explanatory variables on willingness to pay.
Conditional Valuation Method is the only method used to estimate unused values. The amount that people were willing to pay for environmental protection was directly asked using a questionnaire. According to Venkatachalam (2004), willingness to pay is the lowest value individuals place on environmental goods. This method seeks to predict people's willingness to pay considering hypothetical market scenarios.
The results of Aquaculture service modeling
1) Depending on the scale and capacity of rearing in each farm, juvenile fish up to 0.06 kg were released, leading to the production of larger fish up to 1.4 kg as fishery product. Table 1 shows the numbers and pieces of fish. The release period in each farm ranged from 20 to 70 days per year.
2) The amount of fish produced is estimated to be 280 tons per year or one breeding period after calculating the total weight of fish produced by multiplying the number of fish by their weight and eliminating lower weight fish and fish with natural mortality. Finally, all fish in the farm were harvested at the same time.
3) Reducing the inflow of the above two rivers into the Qarah Qeshlaq wetland will not only affect the water quality of the wetland, but also the volume of water in the wetland, which will also negatively affect the performance of fish farming during this period. In other words, the number of farms is reduced from 14 to 13 plots, and water quality affects the performance of the Qarah Qeshlaq and Neor Chay wetlands, reducing from 200,000 to 167934 plots over a year.
4) In terms of crop production, fish farming currently produces the most, followed by the Qarah Qeshlaq wetland, while Neor River and water supply canals are in the last place. Fig. 3 depicts the mean and standard deviation of each farm, with farms 3 and 8 having relatively high production compared to the others. The river is less productive due to the lack of human intervention and the releasing of juvenile fish into the river.
The study area is the Qarah Qeshlaq wetland, with an area of 22 thousand hectares. About 60% of this wetland is in East Azerbaijan province, and 40% of it is located in West Azerbaijan. There are 13 types of land use in the area of the Qarah Qeshlaq wetland, which shows the diversity of land use and the active presence of human factors over nearly 22,000 hectares. Around 46% of the area is used for agricultural purposes, and about 28% of the land contains saline and infertile soil. The level of land use, its importance, and the geometric form have been effective in threatening the Qarah Qeshlaq wetland ecosystem. In this regard, residential centers, as the center of threat, and the access road, as the development of the threat, have contributed the most to the change in land use. Among 14 land uses in the study area, 8 land uses are considered as habitats, of which agricultural lands are habitats for ewe and chicken, barren lands, pastures, salt marshes, and floodplains are habitats for waterfowls, and river, water supply channel, and Qarah Qeshlaq wetland are habitats for aquatics. Considering the average income of each household, the willingness to pay was 50000000 Rials for the villages of Qarah Qeshlaq, Ahmadabad, Salarabad, and Majidabad, with 307 native households, leading to a total amount of 6975418531 Rials for one month. The willingness to pay was 259781500 Rials for 500 non-native people, leading to a total value of 7235200031 Rials. However, based on international calculations, the economic value of the Qarah Qeshlaq wetland was estimated at 227773688 dollars per year, whose significant difference shows less attention to ecosystem services during the lifetime of this wetland.