3D Analyst Tools ArcToolbox

Hillshade, Slope Tools

Hillshade

How to use Hillshade Tool in ArcToolbox ArcMap ArcGIS ??

Hillshade Tool

Hillshade Tool, Raster Surface Toolset, 3D Analyst Toolbox

Hillshade

Creates a shaded relief from a surface raster by considering the illumination source angle and shadows.

1. Input raster

The input surface raster.

2. Output raster

The output hillshade raster.

The hillshade raster has an integer value range of 0 to 255.

3. Azimuth (optional)

Azimuth angle of the light source.

The azimuth is expressed in positive degrees from 0 to 360, measured clockwise from north.

The default is 315 degrees.

4. Altitude (optional)

Altitude angle of the light source above the horizon.

The altitude is expressed in positive degrees, with 0 degrees at the horizon and 90 degrees directly overhead.

The default is 45 degrees.

5. Model shadows (optional)

Type of shaded relief to be generated.

· Unchecked—The output raster only considers local illumination angles; the effects of shadows are not considered.

The output values can range from 0 to 255, with 0 representing the darkest areas, and 255 the brightest. This is the default.

· Checked—The output shaded raster considers both local illumination angles and shadows.

The output values range from 0 to 255, with 0 representing the shadow areas, and 255 the brightest.

6. Z factor (optional)

Number of ground x,y units in one surface z-unit.

The z-factor adjusts the units of measure for the z-units when they are different from the x,y units of the input surface. The z-values of the input surface are multiplied by the z-factor when calculating the final output surface.

If the x,y units and z-units are in the same units of measure, the z-factor is 1. This is the default.

If the x,y units and z-units are in different units of measure, the z-factor must be set to the appropriate factor, or the results will be incorrect. For example, if your z-units are feet and your x,y units are meters, you would use a z-factor of 0.3048 to convert your z-units from feet to meters (1 foot = 0.3048 meter).

Slope

How to use Slope Tool in ArcToolbox ArcMap ArcGIS ??

Slope Tool

Slope Tool, Raster Surface Toolset, 3D Analyst Toolbox

Slope

Identifies the slope (gradient or steepness) from each cell of a raster.

1. Input raster

The input surface raster.

2. Output raster

The output slope raster.

It will be floating-point type.

3. Output measurement (optional)

Determines the measurement units (degrees or percentages) of the output slope raster.

· DEGREE—The inclination of slope will be calculated in degrees.

· PERCENT_RISE—The inclination of slope will be calculated as percent rise, also referred to as the percent slope.

4. Method (optional)

Determines whether to calculate the aspect based on a planar (flat earth) or a geodesic (ellipsoid) method.

· PLANAR—The calculation will be performed on a projected flat plane using a 2D Cartesian coordinate system. This is the default method.

· GEODESIC—The calculation will be performed in a 3D Cartesian coordinate system by considering the shape of earth as an ellipsoid.

The planar method is appropriate to use on local areas in a projection that maintains correct distance and area. It is suitable for analysis that cover areas such cities, counties, or smaller states in area. The geodesic method produces a more accurate result, at the potential cost of an increase in processing time.

5. Z factor (optional)

Number of ground x,y units in one surface z-unit.

The z-factor adjusts the units of measure for the z-units when they are different from the x,y units of the input surface. The z-values of the input surface are multiplied by the z-factor when calculating the final output surface.

If the x,y units and z-units are in the same units of measure, the z-factor is 1. This is the default.

If the x,y units and z-units are in different units of measure, the z-factor must be set to the appropriate factor, or the results will be incorrect. For example, if your z-units are feet and your x,y units are meters, you would use a z-factor of 0.3048 to convert your z-units from feet to meters (1 foot = 0.3048 meter).

6. Z unit (optional)

Linear unit of vertical z-values.

It is defined by a vertical coordinate system if it exists. If a vertical coordinate system does not exist, the z-unit should be defined from the unit list to ensure correct geodesic computation. By default, Meter would be applied.

• INCH—For inches (U.S.)
• FOOT—For feet
• YARD—For yards (U.S.)
• MILE_US—For miles (U.S.)
• NAUTICAL_MILE—For nautical miles
• MILLIMETER—For millimeters
• CENTIMETER—For centimeters
• METER—For meters
• KILOMETER—For kilometers
• DECIMETER —For decimeters