Remzi Karagüzel

Combining AHP with GIS for landfill site selection: a case study in the Lake Beyşehir catchment area (Konya, Turkey).

Landfills are the most common method for the disposal of municipal solid waste (MSW) in Turkey. However, determining the location of landfill sites is a difficult and complex process because it must combine social, environmental and technical parameters. Additionally, it depends on several criteria and regulations. The main objective of this study was to select of a landfill site for the Lake Beyşehir catchment area. The Beyşehir Lake is the largest freshwater lake and drinking water reservoir in Turkey, but there is no controlled landfill site in the region. Therefore, the landfill site should be determined such that the lake is protected. To determine the most suitable landfill site, an analytical hierarchy process (AHP) was combined with a geographic information system (GIS) to examine several criteria, such as geology/hydrogeology, land use, slope, height, aspect and distance from settlements, surface waters, roads, and protected areas (ecologic, scientific or historic). Each criterion was evaluated with the aid of AHP and mapped by GIS. Data were assorted into four suitability classes within the study area, i.e., high, moderate, low and very low suitability areas, which represented 3.24%, 7.55%, 12.70% and 2.81%, of the study area, respectively. Additionally, 73.70% was determined to be completely unsuitable for a landfill site. As a result, two candidate landfill sites are suggested and discussed. The final decision for landfill site selection will require more detailed field studies.

Solid waste disposal site selection with GIS and AHP methodology: a case study in Senirkent–Uluborlu (Isparta) Basin, Turkey

The appropriate site selection for waste disposal is one of the major problems in waste management. Also, many environmental, economical, and political considerations must be adhered to. In this study, landfill site selection is performed using the Geographic Information System (GIS), the Analytical Hierarchy Process (AHP), and the remote sensing methods for the Senirkent–Uluborlu Basin. The basin is located in the Eğirdir Lake catchment area, which is one of the most important fresh water in Turkey. So, waste management must be regulated in the basin. For this aim, ten different criteria (lithology, surface water, aquifer, groundwater depth, land use, lineaments, aspect, elevation, slope, and distance to roads) are examined in relation to landfill site selection. Each criterion was identified and weighted using AHP. Then, each criterion is mapped using the GIS technique, and a suitability map is prepared by overlay analyses. The results indicate that 96.3% of the area in the basin is unsuitable; 1.6%, moderately suitable; and 2.1%, most suitable. Finally, suitable regions in the basin are determined for solid waste landfill disposal and checked in the field. The selected and investigated regions are considered to be suitable for the landfill.

Groundwater balance estimation and sustainability in the Sandıklı Basin (Afyonkarahisar/Turkey)

The Sandıklı (Afyonkarahisar) Basin is located in the southwest of Turkey and is a semi-closed basin. Groundwater is widely used for drinking, domestic and irrigation purposes in the basin. The mismanagement of groundwater resources in the basin causes negative effects including depletion of the aquifer storage and groundwater level decline. To assure sustainability of the basin, determination of groundwater budget is necessary. In this study, the water-table fluctuation (WTF) and the meteorological water budget (MWB) methods were used to estimate groundwater budget in the Sandıklı basin (Turkey). Conceptual hydrogeological model of the basin was used for understanding the relation between budget parameters. The groundwater potential of the basin calculated with MWB method as 42.10 × 106 m3/year. In addition, it is also calculated with simplified WTF method as 38.48 × 106 m3/year.

Assessment of trace metal contents in water and bottom sediments from Eğirdir Lake, Turkey

The concentration of metals (Pb, As, Co, Cu, Ni, Zn, Fe and Mn) was investigated in water and sediment samples of Eğirdir Lake. The Lake is the second largest fresh water lake of Turkey and it is used as drinking water in the region. The anthropogenic pollutants are primary sources of trace metals which are negatively affected lake water quality. These negative effects were observed in both lake water and bottom sediments. According to obtained data, Pb, Cu, Ni, Fe and Zn have significant enrichment in sediments samples. In addition, the hydrodynamic model of the lake was determined as effectively for Pb, Co, Cu, Ni, Zn, Fe and Mn accumulations. Also, the effect of anthropogenic pollutants was found to be more dominant than geogenic effect in metal accumulation of the lake bottom sediments. Therefore, anthropogenic pollutants within the lake basin should be consistently controlled for the sustainable usage of the lake.

Surface runoff and carbonates-based definition of protection zones for Egirdir Lake in western Turkey

Freshwater of Isparta and Egirdir is supplied from the Egirdir Lake, which is the second largest freshwater lake of the Lakes District in Western Turkey. The Egirdir Lake has been studied within the framework of the Basin Protection Plan Special Provisions of the Egirdir Lake. The impact of runoff is taken into account in determining protection zones of the surface water reservoirs in Turkey. An approach that emphasizes the impact of groundwater flow in addition to the surface runoff has been adopted in this study. Water in Lake Egirdir is often classified as the Class II water according to terrestrial water resources quality criteria in Water Pollution Control Regulation of Turkey. The geological and hydrogeological studies reveal a significant amount of groundwater recharge into the Egirdir Lake through carbonate rocks and alluvial deposits outcropping in the basin, which is why Egirdir Lake still has a less contaminated water quality in spite of heavy pollutants. For this purpose, groundwater flow is prominently used in defining protection zones and surface runoff as well. The inner protection zone, which is defined as the 50-day travel time, and the outer protection zone, defined as the 400-day travel time, were estimated by infiltrometer and pumping tests in alluvium. Pumping tests results were used for the determination of hydraulic conductivities and groundwater levels for the determination of hydraulic gradients. Protection zones in karstic areas are based on the vulnerability map and large karstic springs.

A new hydrogeologically based approach to determining protected areas in drinking water supply reservoirs: a case study in the Ağlasun sub-basin (Burdur, Turkey)

This study covers the hydrogeologically based works taking place in the drinking water reservoir drainage basin in the Ağlasun Sub-basin to ensure water quality. The geological units in the Ağlasun Sub-basin are grouped under two units as allochthonous and autochthonous. Autochthonous units are composed of Erenler limestone, Yazir Formation inside reef limestone, the Ağlasun Formation seen as flysch and alluvium. Allochthonous units are composed of Akdağ limestone and ophiolitic complex. Autochthonous-positioned limestones with their dissolution cavities are classified as karstic aquifers. There is no hydraulic relationship between autochthonous-positioned limestones and drinking water reservoir. Allochthonous-positioned limestones are classified as karstic aquifers having large number of spring discharges. In the studied basin, a groundwater vulnerability map has been prepared which is an effective tool in determining the water resource protection areas. The DRASTIC method was used when preparing the groundwater vulnerability map. The Groundwater Depth, Net Recharge, Aquifer Type, Soil Media, Topography, Vadose Zone Effect and Hydraulic Conductivity parameters were used to form thematic maps and were evaluated with the help of ArcGIS technology. The most sensitive areas to groundwater are distinctively the areas covered with alluvium and allochthonous limestone. Springs discharging from these sensitive areas recharge the stream that connects to the reservoir. It is therefore understood that the traditional protection areas determined after the maximum water level are inadequate in protecting the water quality in a drinking water basin. In addition to existing protection zones, this study suggests “hydrogeologically based new protection areas” which also include streams flowing into the reservoir.