عنوان مقاله [English]
In today’s complex and growing world, population growth, changes in the patterns of consumption and quality of life in rural areas have led to many environmental problems. One of the most important problems derived from this issue is the production of rural wastes and their inappropriate management. In the past to the present, waste management has been carried out in an improper and insanitary way, such as removing wastes from residential areas, dumping them on the roadside and burning them. Waste disposal in the aforementioned methods is not only the solution to the problem in the right way, but also the transformation of one type of contamination to another one. This method of waste disposal which is conducted without observing the technical principles, environmental standards and conditions of the region, will create the possibility of environmental, economic and social harms to the region and threaten the rural environment. The solution to this problem is to locate appropriate landfills for rural wastes. This research has selected the southern Soma village in the city of Urmia as the area of interest or study area of this research, considering the above mentioned topics.
Material and Methods
In this research, which is an applied research in terms of the objective, and a descriptive-analytical one in terms of nature, Multi Criteria Evaluation method (MCE) and Geographic Information System (GIS) have been used to identify suitable waste disposal sites. Multi Criteria Evaluation (MCE) is a method used to combine data in terms of their importance in a particular decision-making process. Conceptually, MCE methods including weighting, scoring or quantitative and qualitative ranking of criteria are for demonstrating their importance with regard to one or a set of goals (Ian 2010: 239).
Considering the objective of this study and the analysis tools, the implementation stages of the research are as the following:
- Identifying the required parameters
- Preparing and producing the parameters
- providing the geodatabase and managing the data
- Standardizing the sub-parameters
- Weighting the parameters
- Overlaying the layers
Results and Discussion
Identifying the Determinants
Based on the determinants and according to the Boolean logic, the areas of the South Soma village are either suitable (1) or unsuitable (0) for burying waste materials. The result of this action showed that nearly 70 percent of the village’s area is not suitable for waste burial. In fact, based on the environmental standards of the Environmental Conservation Organization (ECO) of Iran and the related resources, no waste burial should be done in 70% of the village’s area and these areas have been identified as the restricted areas for landfill.
The first phase of locating landfill site
Based on the statistical information of the landfill locating map, 88.92% of the total area of the village is not suitable for waste disposal. Due to severe and hard conditions of the region, the major part of the suitable lands have also many limitations and might be exploited for waste burial only with high economic costs .Therefore, waste disposal in the lands of this zone is practically unjustifiable economically or the topographic situation of the region makes it very difficult to exploit these lands. Accordingly, if we add the limited suitability zone lands to unsuitable and determinant zone, 94% of the village’s area is not suitable for waste burial, and only about 6% of the total area of the village can be used for burying waste materials.
The second phase of locating landfill site: The use of the slope control layer
Accordingly the slope parameter was overlaid on the landfill suitable zone. The slope factor managed to place about 2% of the total 6% of the suitable zone in the medium and low suitability zone, therefore, about 4% of the total area of the village with suitable slope and less than 15% will be suitable for landfill.
In the present research, the suitable landfill sites were identified using Multi-Criteria Evaluation and Geographic Information System. To do this, the suitable lands were proposed for landfill by producing the maps of constraints, geomorphology, climate, water resources, socio-economy, environment and geology-hazards. The results of the first phase showed that about 88.92% of the total area of the village was not suitable for landfill and the determinants and severe geographical conditions are the main obstacles for waste disposal in these areas. Based on the first phase of site location, only 6% of the total area of the village was identified to be suitable lands for landfill. In the second phase, the sites proposed in the first phase were screened again by applying slope control layer. The results of this overlay showed that by applying slope, 2% out of the total 6% suitable area in the previous phase were placed in moderate and low suitable zones. Accordingly, in general, 4% of the total area of the village with a slope of less than 15% were proposed for landfill.