The production of waste has caused environmental crises that pose serious threats to the life of creatures on Earth. This study aimed to evaluate the strategy and location of waste disposal site in Kiyan watershed with an emphasis on EIA through survey-analytical method. Based on the locating process, a suitable landfill site of 10 hectares was selected in the village of Karke-oliya. As basalt-andesite rocks have high permeability and are resistant to erosion, the proposed area has high environmental capacity for waste disposal. Data from the Meteorological Organization show the prevailing wind direction within the study area is northwest. The western wind dominates, and since the villages of the study area are northwest and west of the landfill area, the effects of the landfill's unpleasant odor will be far off. In addition, since the area is enclosed in terms of topography, which can be seen in the transverse and longitudinal profiles of the region, the effect of the displacement of lightweight waste by the wind has been neutralized. It is important to note that the suggested burial ground is far from natural drainage, which makes the area suitable for landfill for hydro geological watershed purposes. The results of the environmental impact assessment also showed that the project has a positive impact of about 45%. Therefore, the proposed site is well-suited to environmental standards.
1. Introduction
Among the problems we face are waste disposal, Infiltration of leachate from landfill into the ground and its arrival in groundwater aquifers. Due to the presence of pollutants such as hydrocarbons, heavy metals and the like, water and soil resources are contaminated, which is one of the most important environmental hazards. Studies show that the geological and hydrogeological conditions of the landfill play an important role in the spread of pollution (Stevanovic, 2019). The location chosen for the landfill should be examined from various aspects such as geology, natural drainage of the area, accessibility to the site, and location measurement. The relationship between structural elements and groundwater capacity showed that Tectonic factors are the main reason for the expansion of structural features and elements (Yazdani and Aryamanesh, 2013). Therefore, before choosing a place for landfilling, the status of groundwater and the type of use of groundwater in the area should be specified. On the other hand, due to the growing need of society for groundwater and the possibility of using this water for drinking, their contamination, even in small amounts, can be problematic. In landfills, the proposed methods and other methods must be used to prevent leachate from entering groundwater, and either dispose of or purify it. Because Kian city does not currently have a landfill and the waste is currently disposed of in an open area near one of the historical hills of the area, locating the landfill is very important. Therefore, the purpose of this study was to strategically evaluate the location of waste disposal in Kian district.
2. Materials and Methods
2.1. Location using Geographic Information System (GIS)
The steps of the location process using the GIS are:
1- Recognition 2- Determining effective data and parameters 3- Studying the characteristics of the study area 4- Collecting and preparing data 5- Preparing maps 6- Weighing maps 7- Combining maps 8- Final maps. The locating process is done by classifying and evaluating different classes related to each of the parameters in the GIS environment (Eftekhari et al., 2019).
2. 2. Hierarchical analysis model (AHP)
The AHP model is one of the most efficient multi-criteria decision-making techniques presented by Thomas L. Saati (1980), This model is based on a pairwise comparison of factors and allows managers and decision makers to consider different scenarios. This technique is one of the most comprehensive systems designed for decision making with multiple criteria, because it provides the possibility of formulating complex natural problems in a hierarchical manner (Ramesht et al., 2013).
2.3. Research method
In the multi-criteria decision literature, several methods have been proposed in weighting the criteria based on the judgments of decision makers. These methods include ranking, grading, pairwise comparison, and balance-permutation analysis. Weighting methods are based on the capabilities of computer software and compatibility, which enabled them in multi-criteria decision analysis based on GIS (Parhizkar and Gilande, 2006). After determining the criteria for locating and classifying maps into different classes on the basis of the impact of the parameters, the importance of each parameter in the weighting format must be specified according to their effectiveness in order to prepare the final map.
3. Results
Based on the results obtained from the location process using the AHP model in GIS environment, several sites were identified in the area, among which one case was selected as a suitable landfill for municipal waste due to hydrological and watershed management characteristics. The proposed land area is 10 hectares. Since the area is enclosed in terms of topography, the effect of lightweight waste movement by the wind is neutralized and is away from natural drainage, which makes the area, in terms of hydrogeology, suitable for waste landfill.
3.1. Environmental Impact Assessment (EIA) with a rapid impact assessment matrix
Environmental Impact Assessment of Kian Waste Landfill Using Rapid Matrix Method shows that the effects in both construction and operation stages are moderately negative and have a positive effect (18). Effects on construction and operation in the physical/ chemical group, have been mostly due to the deformation of the earth and the creation of landscape pollution and soil pollution on a local scale. In the construction and operation phase in the biological/ ecological group, negative effects such as reduced diversity and density of drought plants can be mentioned.
4. Discussion and Conclusion
Based on the locating process, a suitable landfill site of 10 hectares was selected in the village of Karke-Oliya. Due to the fact that the bedrock is basalt-andesite area and these rocks are resistant to erosion and medium permeability, they have the potential for waste disposal; therefore, the proposed area has high environmental capacity for waste landfill.