Hybrid soil thickness mapping using mass conservation and empirical methods

Knowledge graph centered on Hybrid soil thickness mapping using mass conservation and empirical methods with 9 nodes and 15 connections. Top connected: A hybrid data-model approach to map soil thickness, Random Forest, Dynamic cone penetrometer technique, Susan S. Hubbard, Baptiste Dafflon.

Method synopsis

Combines process-based mass conservation equations with empirical curvature relationships to predict soil thickness. Applies different methods based on erosional vs depositional terrain classification.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure as described in the canonical source

Steps below were extracted from the paper that introduces this protocol — A hybrid data-model approach to map soil thickness in mountain hillslopes (2021), Earth Surface Dynamics. Implementations in other papers (listed below) may differ.

1. Process lidar DEM for topographic analysis
   Applied three smoothing techniques to 0.5 m resolution lidar DEM: polynomial fitting of grid cells, spatial smoothing using moving windows, and temporal smoothing over different time periods (0.25 to 3.25 kyr).
   Quantities: 0.5 m resolution DEM, smoothing ranges from 1.5 m to 13.5 m spatial, 0.25 to 3.25 kyr temporalDuration: Data processing phaseConditions: Computational analysis
   Equipment: 0.5 m lidar DEM, GIS software
2. Calculate topographic curvature and derivatives
   Computed curvature (∇·∇η) from processed DEM using second-order derivatives. Applied diffusion equation smoothing with Kd∇·∇η where Kd is diffusion coefficient.
   Quantities: Grid-based calculations across entire study areaDuration: Computational processingConditions: Multiple DEM smoothing scenarios tested
   Equipment: computational software for differential equations
3. Calibrate hybrid model parameters
   Used grid search approach to calibrate seven parameters: normalized soil depth (ho), weathering rate (Pp), mean soil thickness (h̄), curvature slope (a), topography diffusion coefficient (Kd), soil erodibility (Ks), and erosion threshold (Ethre). Parameters calibrated separately for north- and south-facing hillslopes.
   Quantities: 7 parameters total, separate calibration for 2 slope aspectsDuration: Model calibration phaseConditions: Based on field measurement dataset
   Equipment: computational modeling software
4. Perform sensitivity analysis
   Applied Morris one-step-at-a-time method with 20 elementary effects per parameter. Used absolute mean value instead of mean value to avoid influence of non-monotonic effects.
   Quantities: 20 elementary effects calculated per parameterDuration: Model analysis phaseConditions: Statistical analysis of parameter importance
   Equipment: TOUGH2 software, statistical analysis tools

Typical Equipment

• 0.5 m lidar DEM
• GIS software
• computational modeling software
• TOUGH2 software

Output Measurements

• soil thickness maps
• surface transport rates
• soil production rates

Papers Using This Protocol (1)

Places Where Used