Wykorzystanie programów QuantumGIS i SAGA GIS do budowy cyfrowego modelu wysokościowego zlewni Grajcarka
Use of QuantumGIS and SAGA GIS software to build Digital Elevation Model of Grajcarek catchment

Summary/Abstract: In this paper use of 1:10 000 scale topographic maps and open-source GIS software to build Digital Elevation Model (DEM) with 5-meters resolution was analysed. DEM was built from contour lines vectorised in Quantum GIS using five different interpolation methods available in SAGA GIS: Ordinary Kriging, Ordinary Kriging with Block Kriging, Thin Plate Spline (Local), Thin Plate Spline (TIN), Multilevel B-Spline Interpolation. Special attention was given to the accuracy of DEM's built with those methods. DEM's were analyzed by crossvalidation of their surface with elevation points vectorised from topographic maps, which were not used in DEM interpolations. Correctness of generated drainage network was also investigated. Although construction of DEM in presented way is very time-consuming, it is often the only way to build high-resolution DEM of small catchments or other spatial units, which could be used in large-scale hydrological or geomorphological modeling.

• Details
• Contents