GIS-Based IDW Mapping of Soil Index Properties: A Case Study of Elazığ Center

KARABAŞ B., Akbulut N., demirtaş o.

Dicle Üniversitesi Mühendislik Fakültesi Mühendislik Dergisi, cilt.17, sa.1, 2026 (TRDizin)

Özet

In this study, Geographic Information Systems (GIS)-based Inverse Distance Weighting (IDW) spatial mapping of soil index properties was conducted for a 133.65 km² study area using borehole data obtained from the city center of Elazığ. Data from between 33 and 210 selected boreholes were evaluated, and spatial prediction maps were generated based on the Unified Soil Classification System (USCS), Atterberg limits, water content, and groundwater distribution. The results indicate that ML, GM, and CL soil classes are dominant at shallow depths (1.5–4.5 m), while the GM soils coexist with MH soils at intermediate depths (7.5–9 m). At greater depths (15 m), ML, SM, and GM soil types become dominant again. Water content values predominantly range between 11% and 20% across the study area, whereas other ranges (0–10%, 21–30%, and 31–44%) exhibit depth-dependent variations. Overall, the distribution suggests that low to moderate water content predominates and that the groundwater potential of the study area is limited. Based on liquid limit, plastic limit, and plasticity index values, two distinct soil zones were identified using IDW-based spatial prediction maps.