HyLands 1.0: a Hybrid Landscape evolution model to simulate the impact of landslides and landslide-derived sediment on landscape evolution

Abstract

Abstract. Landslides are the main source of sediment in most mountain ranges. Rivers then act as conveyor belts, evacuating landslide-derived sediment. Sediment dynamics are known to influence landscape evolution through interactions among landslide sediment delivery, fluvial transport, and river incision into bedrock. Sediment delivery and its interaction with river incision therefore control the pace of landscape evolution and mediate relationships among tectonics, climate, and erosion. Numerical landscape evolution models (LEMs) are well suited to study the interaction among these earth surface processes. They enable evaluation of a range of hypotheses at varying temporal and spatial scales. While many models have been used to study the dynamic interplay between tectonics, erosion and climate, the role of interactions between landslide-derived sediment and river incision has received much less attention. Here, we present HyLands, a hybrid landscape evolution model integrated within the Topo Toolbox Landscape Evolution Model (TTLEM) framework. The hybrid nature of the model lies in its capacity to simulate both erosion and deposition at any place in the landscape due to fluvial bedrock incision, sediment transport and rapid, stochastic mass wasting through landsliding. Fluvial sediment transport and bedrock incision are calculated using the recently developed Stream Power with Alluvium Conservation and Entrainment (SPACE) model. Therefore, rivers in HyLands can dynamically transition from detachment-limited to transport-limited, and from bedrock to bedrock-alluvial to fully alluviated states. Erosion and sediment production by landsliding is calculated using a Mohr-Coulomb stability analysis while landslide-derived sediment is routed and deposited using a multiple flow direction, non-linear deposition method. We describe and evaluate the HyLands 1.0 model using analytical solutions and observations. We first illustrate the functionality of HyLands to capture river dynamics ranging from detachment-limited to transport-limited configurations. Second, we apply the model to a portion of the Namche-Barwa massif in Eastern Tibet and compare simulated and observed landslide magnitude-frequency and area-volume scaling relationships. Finally, we illustrate the relevance of explicitly simulating landsliding and sediment dynamics over longer timescales for landscape evolution in general and river dynamics in particular. With HyLands we provide a new tool to understand both the long and short-term coupling between stochastic hillslope processes, river incision, and source-to-sink sediment dynamics.

HyLands 1.0: a hybrid landscape evolution model to simulate the impact of landslides and landslide-derived sediment on landscape evolution

“…Documentation, installation instructions and software dependencies for the HyLands project can be found at https://github.com/ BCampforts/topotoolbox (last access: 25 August 2020). Detailed scripts and user manuals for the simulations illustrated in this paper can be found at https://github.com/BCampforts/pub_hylands_ campforts_etal_GMD (last access: 25 August 2020), which is also archived on Zenodo: https://doi.org/10.5281/zenodo.3714182 (Campforts, 2020i). HyLands is platform independent and requires MATLAB 2018a or higher and the Image Processing Toolbox.…”

“…Video supplement. Videos are described in Table 2 (Campforts, 2020f); https://doi.org/10.5446/45971 (Campforts, 2020g); https://doi.org/10.5446/45972 (Campforts, 2020h).…”

CSDMS: A community platform for numerical modeling of Earth-surface processes

“…An example of a recently developed Landlab-built model is HyLands: a landscape evolution model that simulates mass wasting and sediment redistribution on hillslopes. The model was originally writte in a closed-source language (Campforts et al, 2020) Colormap designed by Thyng et al (2016).…”

Numerical modeling of Earth's dynamic surface: a community approach

“…An example of a recently developed Landlab-built model is HyLands: a landscape evolution model that simulates mass wasting and sediment redistribution on hillslopes. The model was originally writte in a closed-source language (Campforts et al, 2020); translating the original code into Landlab converts the original product into a fully open-source tool for the broader community, and provides a new process component to simulate landsliding. The grid engine and other tools available within the Landlab library enabled efficient implementation and provide capabilities for coupling with other, existing Landlab components.…”

“…The evolution of the alluvial fans is further visualised in the movies listed in Table 3. For details regarding the algorithms and physics supporting the HyLands component, see Campforts et al (2020).…”