Slope calculations appear to be 90 degrees off in ArcGIS 3D Analyst?

How does ArcGIS calculate slope?

The slope value is calculated by measuring the angle between topographic surface and the referenced datum. Both planar and geodesic computations are performed using a 3 by 3 cell neighborhood (moving window). For each neighborhood, if the processing (center) cell is NoData, the output is NoData.

Can a slope be over 100 percent?

In theory, a slope analysis on a DEM will calculate slopes of anywhere between 0 and 90 degrees. However, with percentages, anything over a 45 degree slope will be greater than 100%. If slope is rise / run, then a 45 degree slope will have a rise of 1 and a run of 1 which equates to a 100% slope.
 

Is it true that ArcGIS can derive a slope layer in either percent slope or degree slope?

The Slope command takes an input surface raster and calculates an output raster containing the slope at each cell. The lower the slope value, the flatter the terrain; the higher the slope value, the steeper the terrain. The output slope raster can be calculated as percent slope or degree of slope.

How is slope angle calculated?

Angle of slope represents the angle that’s formed between the run (remember it’s an idealized flat surface that ignores elevation change) and your climb’s angular deviation from that idealized flat surface. To calculate this, you divide the rise divided by the run, and then obtain the inverse tangent of the result.

How is slope stability calculated?

If the forces that resist the movement are greater than those driving the movement, the slope is considered stable. A factor of safety (FS) is calculated by dividing the resistance by the driving forces. A factor of safety greater than 1.00 suggests that the slope is stable.

How does the slope function work?

Slope measures the rate of change in the dependent variable as the independent variable changes. The greater the slope the steeper the line. b is the slope of the line. Slope means that a unit change in x, the independent variable will result in a change in y by the amount of b.

What does a 6% slope mean?

A road sign indicating a 6% grade, or 6% slope. A six percent slope means that the road elevation changes 6 feet for every 100 feet of horizontal distance (Figure 1.3). Figure 1.3. A road climbs at a gradient of 6 percent. The road gains 6 feet in elevation for every 100 feet of horizontal distance.

What does a 15% slope mean?

Example: a road with 15% slope has an angle of 8.53°. At a length of 200 feet, a height of 30 feet and a total distance of 202.24 feet is covered.