Document Type : مقاله پژوهشی
The rapid increase in population, economic and technological development along with changing consumption patterns lead to production of large amounts of waste in rural areas. This has caused a serious crisis in human societies. Currently, there is no integrated management of rural waste and rural waste has been converted to non-degradable waste with long-term survival. This waste remains in villages and rural areas for long time and gives villages an ugly face and it results in different types of air, water, and soil pollution. Thus, protecting the environment of rural areas is of significant importance for rural development requirements. In this paper we attempted to impose a variety of spatial analysis operations, along with the use of GIS technology and AHP model in order to locate the optimal boundaries - with the least adverse environmental impacts - in rural areas used for waste disposal.
2. Study Area
Khaf, the border counties of Khorasan Razavi that is located between latitudes of 34°01'“N to 34°59'“N and longitudes of 59°28'“E to 60°55'“E is located on 250 km southeast of Mashhad in Iran's eastern border, adjacent to Afghanistan in a relatively broad plains.
3. Material and Methods
In this paper, a descriptive - analytical method is applied based on the purpose of the study. In this paper, status quo analysis and data modeling procedures are used. To do this, first, we created database of GIS consisting of spatial data and descriptive data in forms of algorithm, spatial data (slope, land use, distance of faults, stream, roads and water sources, groundwater levels, etc.) of 10 Villages of Khaf city (with an approved pilot plan) from corresponding maps and by using ArcGIS software. Also, descriptive data were digitalized and stored to provide analysis capabilities. Then, a questionnaire was designed and completed by 30 people including three groups of university professors, consultant engineers of rural pilot projects preparation, and experts of Housing Foundation of Islamic Revolution. Ultimately, using weight of the layers in AHP model, and GIS database with overlapping operations of different maps in locating, landfill in rural areas were identified compared with current and proposed location of (approved by plane pilot) rural waste disposal.
The main research question of the present study is that what factors influence the location of landfill in rural areas? And to what extent the current and proposed waste disposal site in the villages under study is in compliance with positioning of landfill in GIS environment?
4. Results and Discussion
Selecting a landfill is the most important step in developing a satisfactory plan for waste disposal. While preparing the master plan, the sanitary landfill, if possible, should be determined and purchased. The most important factor in a successful operation of a landfill is its appropriate site selection. Many factors should be evaluated for the suitability of a landfill. Type of selected terrain has a direct impact on designing, exploitation operation, and required tools.
11 experimental parameters used in landfill location are:
«Slope, distance from historical centers, distance from fault, distance from the watercourse, distance from the ways of communication, material of mother stone, lands use, distance from population centers, distance from the drinking water wells, level of underground waters, and the soil depth.»
In the evaluation performed, soil depth with coefficient of 264.0 has had the greatest impact on positioning of landfill and land use with coefficient of 014.0, has had the lowest impact. In a comparative study between the existing landfill in rural locations with optimum positioning obtained by the software, it is identified that landfill in Chaman Abad-Vali Abad village is located in quite appropriate area and as for two villages, Syjavand and Chahzoul in appropriate area while landfills in other sample villages are located in fairly proper and improper areas.
Research findings show that using this method and in case of multi-options and a large number of criteria the final option can be selected accurately. Logical and accurate weighting should be done for criteria and options to select the ultimate site and prioritization of landfills can be conducted accurately. The results can be used in regional planning to minimize urban and rural settlements damages. The results of this research can be planned with environmental and socio-economic perspectives and considerations and lead to a sustainable development.
According to the studies and results obtained during the research process, the following suggestions are offered:
To identify suitable landfills in the rural areas, one of the best models is AHP model, which along with other models (ANP) and using ArcGIS software paly an important role for making decisions and guiding future development in rural areas;
Rural plans consultants' coordination with local officials, particularly, rural Islamic councils and county rural municipality administrators is necessary to select and transfer landfill space because, finally, implementation of this project goes back to the local authorities. This place for waste disposal for a number of villages in a given geographical area is homogeneously identified.
Positioning landfills in rural areas is not a particular case for a particular village but a suitable location can be used for a collection of villages. Determining a suitable location for homogeneous rural areas and interval of garbage collecting that is economical.