Topographic Wetness Index and Soil Moisture Measurements Across 5,200 Plots

Henri Riihimäki from the University of Helsinki provides data from a study evaluating the Topographic Wetness Index (TWI) as a proxy for soil moisture. The dataset includes over 46,000 soil moisture measurements from 5,200 study plots, used to test TWI predictions derived from 11 flow-routing algorithms at Digital Elevation Model resolutions from 1 to 30 meters. The results indicate the predictive capability of TWI is modest, with the best performance reaching an R² of 23.7%.

Use Cases

• Benchmarking flow-routing algorithms for soil moisture prediction based on the 11 algorithms tested.
• Assessing the impact of DEM grid resolution on terrain index accuracy based on the 1-30 meter resolution analysis.
• Validating topographic wetness index models against field measurements based on the over 46,000 soil moisture data points.
• Evaluating the sensitivity of hydrological models to DEM height errors based on the described error sensitivity tests.

Strengths

• Includes a substantial volume of field measurements with over 46,000 soil moisture data points.
• Compares a wide range of methodological variables, testing 11 flow-routing algorithms.
• Analyzes data across multiple spatial scales, using DEM resolutions from 1 to 30 meters.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Last update date is unknown; freshness unverified.

Provenance

Source

University of Helsinki

Collection Method

Field-quantified soil moisture measurements and derived TWI calculations from DEMs.