Table 1 Environmental variables, description, descriptive statistics, and references

 Clay, %

<  0.002 mm particle size

 Sand, %

0.05–2 mm particle size

 Silt, %

0.002–0.05 mm particle size

 Analytical hillshading, radians

The angle between the surface and the incoming light beams

[22]

 Aspect, radians

Grid cells of aspect or facing direction

[22]

 Catchment area, m²

Upslope area of each grid cell contributing to runoff

[22]

 Channel network base level, m

Interpolated channel network base level elevations

[4, 8]

 Curvature classification

Surface curvature based terrain classification

[4]

 Elevation, m

Digital Elevation Model, 10 × 10 m

[4, 22]

 Flow accumulation

Number of upslope cells

[22]

 Landsat 8 Band 1

Coastal/Aerosol

[4, 5, 23]

 Landsat 8 Band 10

Thermal Infra-Red Sensor 1

[4, 5, 23]

 Landsat 8 Band 11

Thermal Infra-Red Sensor 2

[4, 5, 23]

 Landsat 8 Band 2

Blue band

[4, 5, 23]

 Landsat 8 Band 3

Green band

[4, 5, 23]

 Landsat 8 Band 4

Red band

[4, 5, 23]

 Landsat 8 Band 5

Near Infra-Red band

[4, 5, 23]

 Landsat 8 Band 6

Short Wave Infra-Red 1 band

[4, 5, 23]

 Landsat 8 Band 7

Short Wave Infra-Red 2 band

[4, 5, 23]

 Latitude, m

UTM Northing: the y coordinate from the equator

 Longitude, m

UTM Easting: the x coordinate from the central meridian

 LS factor

Slope length and steepness factor as used by the Universal Soil Loss Equation (USLE)

[22, 24]

 Mass balance index

Characteristics of soil and accumulation

[4]

 Mountain ridge proximity, m

Distance to the mountain ridge

This study

 MRVBF

Flatness on valley bottom

[4, 25]

 Mid-slope position

Relative vertical distance to the mid-slope valley or crest directions

[4, 25]

 NDVI

Normalized difference vegetation index

[4]

 Normalized height

Height ratio above the channel to the ridge

[4]

 Overland flow distance, m

Overland flow distance to the drainage channel

[13]

 Profile curvature, m^− 1

Shape of the surface in the immediate neighborhood

[13, 26]

 S factor

Slope steepness factor as used by the Universal Soil Loss Equation (USLE)

[24]

 SAGA wetness index

Topographic Wetness Index (TWI) based on a modified catchment area

[22, 25]

 Sky view factor

Ratio of visible sky viewed from the ground

[4]

 Slope, %

Slope gradient

[4, 22]

 Slope height, m

Vertical distance from the base of the slope to the crest

[4, 25]

 Stream proximity, m

Proximity to stream

[4, 8]

 Terrain ruggedness index

Terrain heterogeneity

[22]

 Valley depth, m

Vertical distance to a channel network base level

[22]

 Vertical distance to channel network, m

Altitude above the channel network in the same units as the elevation data

[8, 22]

 Vertical overland flow distance, m

Vertical distance projected of mean runoff length

[4]