Short Communication: TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences

Schwanghart, Wolfgang; Scherler, Dirk

doi:10.5194/esurf-2-1-2014

Cited by 880 publications

(779 citation statements)

References 37 publications

Supporting

Mentioning

708

Contrasting

Unclassified

Order By: Relevance

“…A software implementation of the CRS algorithm is available for the MATLAB software TopoToolbox at https: //github.com/wschwanghart/topotoolbox (Schwanghart and Scherler, 2014). The software allows for the tuning of several parameters.…”

Section: Resultsmentioning

confidence: 99%

Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques

2017

Self Cite

View full text Add to dashboard Cite

Abstract. The analysis of longitudinal river profiles is an important tool for studying landscape evolution. However, characterizing river profiles based on digital elevation models (DEMs) suffers from errors and artifacts that particularly prevail along valley bottoms. The aim of this study is to characterize uncertainties that arise from the analysis of river profiles derived from different, near-globally available DEMs. We devised new algorithmsquantile carving and the CRS algorithm -that rely on quantile regression to enable hydrological correction and the uncertainty quantification of river profiles. We find that globally available DEMs commonly overestimate river elevations in steep topography. The distributions of elevation errors become increasingly wider and right skewed if adjacent hillslope gradients are steep. Our analysis indicates that the AW3D DEM has the highest precision and lowest bias for the analysis of river profiles in mountainous topography. The new 12 m resolution TanDEM-X DEM has a very low precision, most likely due to the combined effect of steep valley walls and the presence of water surfaces in valley bottoms. Compared to the conventional approaches of carving and filling, we find that our new approach is able to reduce the elevation bias and errors in longitudinal river profiles.

show abstract

Section: Resultsmentioning

confidence: 99%

Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques

2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…3, using TopoToolbox2 (Schwanghart and Scherler, 2014). For the case in which δ = 1.5 the scaling between channel slopes and catchment drainage areas, the slope-area exponent θ , is equal to −0.42, and for δ = 1.3, θ is equal to −0.23 (Fig.…”

Section: Erosion By Sediment Transportmentioning

confidence: 99%

Numerical modelling of landscape and sediment flux response to precipitation rate change

et al. 2018

View full text Add to dashboard Cite

Abstract. Laboratory-scale experiments of erosion have demonstrated that landscapes have a natural (or intrinsic) response time to a change in precipitation rate. In the last few decades there has been growth in the development of numerical models that attempt to capture landscape evolution over long timescales. However, there is still an uncertainty regarding the validity of the basic assumptions of mass transport that are made in deriving these models. In this contribution we therefore return to a principal assumption of sediment transport within the mass balance for surface processes; we explore the sensitivity of the classic end-member landscape evolution models and the sediment fluxes they produce to a change in precipitation rates. One end-member model takes the mathematical form of a kinetic wave equation and is known as the stream power model, in which sediment is assumed to be transported immediately out of the model domain. The second end-member model is the transport model and it takes the form of a diffusion equation, assuming that the sediment flux is a function of the water flux and slope. We find that both of these end-member models have a response time that has a proportionality to the precipitation rate that follows a negative power law. However, for the stream power model the exponent on the water flux term must be less than one, and for the transport model the exponent must be greater than one, in order to match the observed concavity of natural systems. This difference in exponent means that the transport model generally responds more rapidly to an increase in precipitation rates, on the order of 10 5 years for post-perturbation sediment fluxes to return to within 50 % of their initial values, for theoretical landscapes with a scale of 100 × 100 km. Additionally from the same starting conditions, the amplitude of the sediment flux perturbation in the transport model is greater, with much larger sensitivity to catchment size. An important finding is that both models respond more quickly to a wetting event than a drying event, and we argue that this asymmetry in response time has significant implications for depositional stratigraphies. Finally, we evaluate the extent to which these constraints on response times and sediment fluxes from simple models help us understand the geological record of landscape response to rapid environmental changes in the past, such as the Paleocene-Eocene thermal maximum (PETM). In the Spanish Pyrenees, for instance, a relatively rapid (10 to 50 kyr) duration of the deposition of gravel is observed for a climatic shift that is thought to be towards increased precipitation rates. We suggest that the rapid response observed is more easily explained through a diffusive transport model because (1) the model has a faster response time, which is consistent with the documented stratigraphic data, (2) there is a high-amplitude spike in sediment flux, and (3) the assumption of instantaneous transport is difficult to justify for the transport of large grain sizes as an alluvi...

show abstract

“…We use the ice thickness and bedrock elevation from Bedmap2 (Fretwell et al, 2013). The subglacial streamlines are generated from the hydraulic potential gradient using a topographic analysis software, TopoToolbox (Schwanghart and Scherler, 2014).…”

Section: Hydraulic Potentialmentioning

confidence: 99%

Active subglacial lakes and channelized water flow beneath the Kamb Ice Stream

et al. 2016

View full text Add to dashboard Cite

Abstract. We identify two previously unknown subglacial lakes beneath the stagnated trunk of the Kamb Ice Stream (KIS). Rapid fill-drain hydrologic events over several months are inferred from surface height changes measured by CryoSat-2 altimetry and indicate that the lakes are probably connected by a subglacial drainage network, whose structure is inferred from the regional hydraulic potential and probably links the lakes. The sequential fill-drain behavior of the subglacial lakes and concurrent rapid thinning in a channel-like topographic feature near the grounding line implies that the subglacial water repeatedly flows from the region above the trunk to the KIS grounding line and out beneath the Ross Ice Shelf. Ice shelf elevation near the hypothesized outlet is observed to decrease slowly during the study period. Our finding supports a previously published conceptual model of the KIS shutdown stemming from a transition from distributed flow to well-drained channelized flow of subglacial water. However, a water-piracy hypothesis in which the KIS subglacial water system is being starved by drainage in adjacent ice streams is also supported by the fact that the degree of KIS trunk subglacial lake activity is relatively weaker than those of the upstream lakes.

show abstract

Short Communication: TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences

Cited by 880 publications

References 37 publications

Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques

Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques

Numerical modelling of landscape and sediment flux response to precipitation rate change

Active subglacial lakes and channelized water flow beneath the Kamb Ice Stream

Contact Info

Product

Resources

About