مکان یابی مناسب جهت دفن بهداشتی زباله های شهری با استفاده از سنجش از دور و GIS (مطالعه موردی: شهر گنبد کاووس)

Background and purpose: Finding a suitable location for the solid wastes is necessary for urban development projects. The Gonad city with a population of 131 108 people will produce 120 tons of garbage per day. This amount of wastes is buried in two temporary sites (adjacent of the river) and a permanent. Wastes leachate infiltration into the ground water river cause pollution and other environmental problems is due to wrong solid waste site selection. Aim of this study is Landfill Site Selection for solid waste of Gonbad City, based on the geomorphologic features using geographical information system (GIS). Materials and methods: In this study, the key criteria involved in the landfill site selection were identified based on area morphological characteristics. Data, including satellite imagery LandSAT ETM +, IRS, photo mosaic as Google Earth location based, topographic maps, slope, DEM, underground water depth, ways network, hydrography networks, geomorphology, geology, soils maps and wind direction data, as entry criteria were transferred to the GIS database. In the present study we used two combined technologies (remote sensing and GIS). Mathematical method of weighting was used. Then, weighting of each parameter is done based on Index Overlay. Then, after scoring data to integrate the layers and obtain the appropriate results, Index Overlay was used. Results: Initially Boolean logic, and later fuzzy logic model with user based membership functions with WLC and OWA methods, were used to site selection. Through field visits, three locations for comparison and evaluation through weighting of parameters based on Index Overlay process were selected and ultimately by doing closer studies on the selected locations and exerting appropriate weights on each of the locations, prioritize sites for sanitary landfill, were marked on the map. Finally, appropriate locations for municipal solid waste as raster pixel size of 30 x 30 m were determined. All three locations were selected for evaluation of waste disposal. According to surveys and maps of GIS, the results showed that the No. 1 location for different reasons, compared with No. 2 and the current waste disposal site, is more appropriate. Conclusion: Evaluation of Geomorphologic and topographic characteristics of the study area showed that the underground water level is a key factor in this site selection in the North East study area that in Site Number One is greater than other areas.