Extraction of thalweg networks from DTMs: application to badlands
نویسندگان
چکیده
To study gully spatial patterns in the badlands using a continuous thalweg vector network, this paper presents methods to extract the badlands’ thalweg network from a regular grid digital terrain model (DTM) by combining terrain morphology indices with a drainage algorithm. This method will delineate a thalweg only where the DTM denotes a significant curvature with respect to DTM accuracy and relies on three major steps. First, discontinuous concave areas were detected from the DTM using morphological criteria, either the plan curvature or the convergence index. Second, the concave areas were connected using a drainage algorithm, which provides a continuous, thick, tree-structured scheme. We assumed that these areas were physically significant and corresponded to a gully floor. Finally, the thick path was reduced to its main course and vectorised to obtain a thalweg network. The methods were applied to both virtual and actual DTM cases. The actual case was a LiDAR DTM of the Draix badlands in the French Alps. The obtained networks were quantitatively compared, both with a network obtained using the usual drainage area criteria and with a reference network mapped in the field. The CI-based network showed the great potential for thalweg network extraction. Correspondence to: N. Thommeret ([email protected])
منابع مشابه
Terrain surfaces and 3D landcover classification from small footprint full-waveform lidar data: Application to badlands
This article presents the use of new remote sensing data acquired from airborne full-waveform lidar systems. They are active sensors which record altimeter profiles. This paper introduces a set of methodologies for processing these data. These techniques are then applied to a particular landscape, the badlands, but the methodologies are designed to be applied to any other landscape. Indeed, the...
متن کاملVery High Resolution Stereo Dtm Extraction and Its Application to Surace Roughness Estimation over Martian Surface
We have developed a processing workflow to extract very high resolution DTMs up to 0.5-4m grid-spacing from HiRise (Kim and Muller, 2007) and 12-18m gridded DTMs from CTX stereo pairs. This workflow relies on combining these data with the outputs of the UCL HRSC stereo processor, which is capable of producing 30-100m DTMs. This provides a unique capability to observe Martian topography at multi...
متن کاملUnmanned Aerial Vehicle (UAV) for Monitoring Soil Erosion in Morocco
This article presents an environmental remote sensing application using a UAV that is specifically aimed at reducing the data gap between field scale and satellite scale in soil erosion monitoring in Morocco. A fixed-wing aircraft type Sirius I (MAVinci, Germany) equipped with a digital system camera (Panasonic) is employed. UAV surveys are conducted over different study sites with varying exte...
متن کاملReconstruction of 2D river beds by appropriate interpolation of 1D cross-sectional information for flood simulation
The 2D numerical simulation of river flow requires a large amount of topographic data to build an accurate Digital Terrain Model which must cover the main river channel and the area likely to be flooded. DTMs for large floodplains are often generated by LiDAR flights. However, it is often impossible to obtain LiDAR data of permanently inundated river beds. These areas are often surveyed and dis...
متن کاملAn objective approach for feature extraction: distribution analysis and statistical descriptors for scale choice and channel network identification
A statistical approach to LiDAR derived topographic attributes for the automatic extraction of channel network and for the choice of the scale to apply for parameter evaluation is presented in this paper. The basis of this approach is to use distribution analysis and statistical descriptors to identify channels where terrain geometry denotes significant convergences. Two case study areas with d...
متن کامل