Mapping of erosion rates in marly badlands based on a coupling of anatomical changes in exposed roots with slope maps derived from LiDAR data

Abstract

Black marls form very extensive outcrops in the Alps and constitute some of the most eroded terrains, thus causing major problems of sedimentation in artificial storage systems (e.g. reservoirs) and river systems. In the experimental catchments near Draix (France), soil erosion rates have been measured in the past at the plot scale through a detailed monitoring of surface elevation changes and at the catchment scale through continuous monitoring of sediment yield in traps at basin outlets. More recently, erosion rates have been determined by means of dendrogeomorphic techniques in three monitored catchments of the Draix basin. A total of 48 exposed roots of Scots pine have been sampled and anatomical variations in annual growth rings resulting from denudation analysed. At the plot scale, average medium-term soil erosion rates derived from exposed roots vary between 1·8 and 13·8 mm yr −1 (average: 5·9 mm yr −1 ) and values are significantly correlated with slope angle. The dendrogeomorphic record of point-scale soil erosion rates matches very well with soil erosion rates measured in the Draix basins. Based on the point-scale measurements and dendrogeomorphic results obtained at the point scale, a linear regression model involving slope angle was derived and coupled to high-resolution slope maps obtained from a LiDAR-generated digital elevation model so as to generate high-resolution soil erosion maps. The resulting regression model is statistically significant and average soil erosion rates obtained from the areal erosion map (5·8, 5·2 and 6·2 mm yr −1 for the Roubine, Moulin and Laval catchments, respectively) prove to be well in concert with average annual erosion rates measured in traps at the outlet of these catchments since 1985 (6·3, 4·1 and 6·4 mm yr −1 ). This contribution demonstrates that dendrogeomorphic analyses of roots clearly have significant potential and that they are a powerful tool for the quantification and mapping of soil erosion rates in areas where measurements of past erosion is lacking.

Dynamics of gully side erosion: a case study using tree roots exposure data

“…Dendrogeomorphic analysis enabled reconstruction of a 41 year chronology of erosion processes (AD 1972(AD -2013 and discovered 23 event years. Dendrogeomorphic studies of erosion processes usually use anatomical analysis of coniferous species [14,40,41]. This preference comes from the quite clear visible anatomical reaction of tree roots on exposure.…”

“…Models are constructed using geodetic measurements, photogrammetry e.g. [12,13] or laser altimetry [14]. The third type of methods is based on mathematical models of erosion processes e.g.…”

Response of anatomical structures in tree roots to an erosion event on the southeastern Tibetan Plateau

“…Moreover, the existing microscopic approaches and proposed equations (Gärtner, 2007) have been checked for accuracy against other systematically measured rates of erosion at the same sites (Corona et al, 2011). The advantage of using exposed roots compared with common erosion measurement techniques is that the area's erosion rates, as well as its variations in erosion rate, can be determined from a spatial and a temporal point of view, especially in regions lacking detailed historical records (Bodoque et al, 2005).…”

“…This tool is one of the most accurate nonsystematic sources of data for dating events with annual or even seasonal precision over several centuries (Corona et al, 2011). Dendrogeomorphology uses different A C C E P T E D M A N U S C R I P T…”

Direct Measurements of Bedrock Incision Rates on the Surface of a Large Dip-slope Landslide by Multi-Period Airborne Laser Scanning DEMs

“…The evaluation of the erosion rate is important in the study of landform evolution, slope and channel interactions, landslide effects, sediment transport processes, and so on. The methods for calculating the erosion rate include the cross section measurement method [15,16], the erosion pin method [17], radiometric dating [18][19][20][21][22][23][24][25], the river suspended-sediment discharge technique [26,27], dendrogeomorphological methods (based on tree-ring analysis from exposed roots) [28,29], interferometric synthetic aperture radar (InSAR) [6],…”