Soil Conservation Service (SCS) curve number (CN) is used to calculate the potential runoff value in ungauged catchment basins. The CN method was applied to calculate the runoff in the catchment basin of the Yamula Dam which is located on the Kizilirmak River in the semi-arid climate of the Central Anatolia Region of Turkey. The analysis of the relation between the land use change and the change of the curve number (change of the runoff values) in the catchment basin can be calculated through geographic information system (GIS) techniques by using the data obtained from satellite images. Using GIS analysis with Python language, SCS-CN technique was applied to study area efficiently. The estimated CN values indicate an uptrend in proportion to the increase in the water level and agricultural lands in the catchment basin. This change is relevant to the land use/land cover (LULC) and the land inclination and in connection with the morphological structure of the soil.