Abstract
River terraces are one of the typical and widespread Quaternary fluvial landforms in Latvia. Until recently, distinguishing and mapping of these features have required extensive field surveys. However, the availability of high resolution digital elevation models (DEM) derived from airborne laser altimetry and application of modern geographic information systems (GIS) provides sufficient background to resolve these tasks. In this study, we apply an integrated methodology based on using of remote sensing, i.e. laser scanning or Light Detection and Ranging (LiDAR) data and combining of semi-automated TerEx tools for the detection of fluvial terraces in DEM. The empirical tests performed using the tools in the study area reveal that the application of TerEx gives the reliable results. However, presence of minor landforms which increase the topographical roughness of the surface directly influence the quality of extracted data, thus leading to the necessity of additional manual editing. The obtained data indicate that the terrace sequence in the Augšdaugava spillway valley consists of eight different terrace levels – T1 to T8. Only terraces T1 and T2 are easily recognizable in the study area, whereas the upper terraces do not have explicit edges.
Highlights
Fluvial terraces are rather common landscape elements of many watercourses located in different regions across the entire planet
The main goal of the study presented in this article was to apply an integrated methodology based on using of remote sensing (LiDAR) data and combining of different semi-automated geographic information systems (GIS) analysis tools for the detection, delineation and mapping of fluvial terraces in digital elevation models (DEM)
This study suggests the novelty of using high-resolution DEM for processing data on elevation with GIS tools to identify and delineate geomorphological features
Summary
Fluvial terraces are rather common landscape elements of many watercourses located in different regions across the entire planet These relief features associated with river valleys are typical and widespread Quaternary fluvial landforms in Latvia too [1]. Stream terraces can be characterized as geomorphological units of river valleys that developed through the fluvial morphogenesis, i.e. downcutting of water stream into a previously formed floodplain [2]. This process leads to the formation of a distinctive step-like topographic cross profile, where terraces are situated at a higher elevation above the current floodplain. Fill terraces typically are developed in valleys as a response to stabilization or rise in base level and are characterized by thick deposits of alluvial material covering terrace surfaces [4], [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
