APPLICATION OF GIS PROCEDURE FOR RIVER TERRACE EXTRACTION FROM A LiDAR- BASED DIGITAL ELEVATION MODEL: THE SAVA RIVER VALLEY NW OF ZAGREB, CROATIA

Abstract

River terraces and fl oodplains indicate channel-sediment dynamics and represent important landform features, which can be used to untangle the evolutionary history of climate and tectonic conditions in a certain area. With the availability of high-resolution topographic data, it has recently become feasible to apply GIS procedures for the identifi cation of these subtle landform features. In this study, the TerEx Toolbox, a GIS extension for semiautomatic terrace extraction was applied on the LiDAR based DEM of the Sava River, west of Zagreb in Croatia. The aim of this research was to compare results obtained by TerEx to the existing geological map from the 1970s, which shows sediments of the recent fl ow (routinely fl ooded area) and two abandoned Holocene river terraces in the study area. The TerEx output was validated using hillshaded DEM, a historical map of the study area, orthophoto imagery, topographic cross sections and fi eld investigations. TerEx has successfully extracted Holocene terraces and risers shown on the geological map but in some parts of the study area, their position and extent was diff erent. The presented study shows that results obtained by TerEx, in particular if used in combination with other data sources, can eff ectively focus fi eldwork and contribute to new unbiased interpretation of terrain morphology.

An index to assess the extent and success of river and floodplain restoration: Recognising dynamic response trajectories and applying a process‐based approach to managing river recovery

“…The Sava River has been rationalized considerably (Figure 5) during the 19th and 20th centuries. The total floodplain area and active channel area (anastomosing river channel, comprising meanders separated by large vegetated islands, see Trenc, Matoš, Velić, & Perković, 2019 for details) has been reduced as part of Sava flood regulation (using stabilized stone banks and embankments). Here the main parameters used to assess NCI were channel and island areas in an originally anastomosing system west of Zagreb.…”

Tectonic Geomorphology of the Karangsambung Area, Central Java, Indonesia

“…The river terrace deposits (T-1 to T-4) are composed of a layer of cobble, gravel, sand, and overlying soil (see Figure 14). River terraces and floodplains indicate channel-sediment dynamics and represent important landform features, which can be used to untangle the evolutionary history of climate and tectonic conditions in a certain area (Trenc et al, 2019). Regional tectonic strength significantly impacts river terraces' formation, similar to the Manas River in China (Zhijun Gong, 2014).…”