Tips for Map Due for Lab 1

• Complete Exercise (Find Potential Youth Center Locations) through step 6. You should now have the potential youth center locations. Do NOT apply the map template.

• Insert – New Data Frame• Copy and Paste Layers in the New Data Frame• Use one Data Frame for a Small Map (zoomed out to

full extent) and one Data Frame for a Large Map (zoomed in to potential youth center locations).

• Switch to the Layout View • Create your map with Title, Data Frames, Legend,

Scale Bars, Name, North Arrow• Another tip is to remember going to Layer Properties

(Rt-Click on the Layer) and choose the Labels tab to edit the labels (size, appearance, etc.) (also change layer name)

If you use TA Computers

• Need to update the data to version 9.2 using ArcCatalog

If you use TA Computers

Learning ArcGIS Spatial Analyst Topics Covered in Module 1

CVEN 2012 – GeomaticsUniversity of Colorado – Boulder

April 2006

Alyssa McCluskey

Topics Covered in Lab Exercise

• understand how ArcGIS Spatial Analyst fits into the geoprocessing framework

• set up an analysis environment

• run Spatial Analyst operations using a tool dialog, the command line, and a model

• convert between feature and raster data

• reclassify data

Why do we need rasters (grids)?

• Deal with geographic objects that are distributed continuously across a surface.

• Temperature, rainfall, soil acidity, elevation, land cover

• Distance to nearest hospital, noise levels

• While they don’t have a ‘shape’ they do have a value at any given location.

Geoprocessing

• A GIS operation used to manipulate GIS data. • A typical geoprocessing operation takes an input

dataset, performs an operation on that dataset, and returns the result of the operation as an output dataset.

• Common geoprocessing operations include geographic feature overlay, feature selection and analysis, topology processing, raster processing, and data conversion.

• Geoprocessing allows for definition, management, and analysis of information used to form decisions.

Geoprocessing Examples

• From Elevation Data– Create Slope Data, Hillshade Data, Aspect

Data

• Converting to/from Raster Data

Performing Geoprocessing

You can use

• a tool's dialog,

• the command line,

• a model,

• or a script,

depending on your needs or preferences.

Performing Geoprocessing

The ArcGIS geoprocessor has one integrated dialog that sets processing environments for all outputs; shapefiles, rasters, geodatabase feature classes, and so forth.

Setting Default Environment Setting

Input Raster Output Extent Output Cell Size

Mask Output Raster

Analysis Properties

Set Geoprocessing Environment

Or access from Tools - Options

Set Geoprocessing Environment

Set Geoprocessing Environment

Hillshade Tool

• The Hillshade tool creates a shaded relief raster from a raster.

• Draws shadows on a map to simulate the effect of the sun's rays over the varied terrain of the land.

• The hypothetical illumination of a surface according to a specified azimuth and altitude for the sun. Hillshading creates a three-dimensional effect that provides a sense of visual relief for cartography, and a relative measure of incident light for analysis.

Run Spatial Analyst using

TOOL DIALOGUE

Hillshade Tool from Tool Dialog

Hillshade Tool from Tool Dialog

Hillshade Tool Result

Elevation Data Hillshade Result

SLOPE

• The incline, or steepness, of a surface. • Slope is the rate of maximum change in z-value

from each cell.• Slope can be measured in degrees from

horizontal (0–90), or percent slope (which is the rise divided by the run, multiplied by 100).

• A slope of 45 degrees equals 100 percent slope. As slope angle approaches vertical (90 degrees), the percent slope approaches infinity.

• The slope for a cell in a raster is the steepest slope of a plane defined by the cell and its eight surrounding neighbors.

Run Spatial Analyst using

COMMAND LINE

Using Command Line

SLOPE Command

Slope_sa <in_raster> <out_raster> {DEGREE | PERCENT_RISE} {z_factor}

Slope

Elevation Data Slope

Run Spatial Analyst using

MODEL BUILDING

Model Building – Add Toolbox for New Model

Model Building

Model Building

DRAG AND DROP

Model Building

DRAG AND DROP

Model Building

DRAG AND DROP

Model Building

DRAG AND DROP

Note: Unshaded

Model Building

Auto Layout Add Connection

Model Building - Execute

Run

Model Building - Execute

Drop Shadows = Model has been executed

Model BuildingAdding Results to Display

Adds output as layer

ASPECT

• The compass direction that a topographic slope faces, usually measured in degrees from north. Aspect can be generated from continuous elevation surfaces.

• The conceptual center of a projection system.

Aspect Tool Result

Elevation Data Aspect Result

Convert Feature to/from Raster

Convert Feature to Raster• You can convert point, line,

and polygon features from any type of source file to a raster using either string and numeric attribute fields.

• If more than one point is found in a cell, the cell is given the value of the first point it encounters.

• When you convert polygons, Spatial Analyst assigns each cell the value of the polygon that contains the centroid of the cell.

Convert Raster to Feature• The point coordinates are

those of the centroid of the cell.

Convert Feature to Raster

Convert Feature to Raster

Convert Feature to Raster

Attribute from Road Layer

Convert Feature to Raster

Extract Data by Using a Mask

Extracts the cells of a raster that correspond to the areas defined by a mask

Extract Data Using Mask

Extract Data Using Mask

Extract Data Using Mask

Extract Data Using Mask

Reclassifying

• Reclassification is the process of reassigning a value, a range of values, or a list of values in a raster to new output values.

• One reason is to set specific values to NoData to exclude them from analysis.

• Still another reason is to assign values of preference, priority, sensitivity, or similar criteria to a raster.

Reclassify Continuous Data

Reclassify

Reclassify

Classification

Different Classifications

• Natural Break: Manually partitions data into classes based on natural groups in the data distribution. Natural breaks occur in the histogram at the low points of valleys.

• Equal-Interval: Divides a set of attribute values into groups that contain an equal range of values.

• Quantile: Distributes a set of values into groups that contain an equal number of values.

Different Classifications

Natural Breaks QuantileEqual-Interval

Reclassify Vegetation

• Rank vegetation based on tolerance to drought (low value = high tolerance)

Reclassify Vegetation

Reclassify Vegetation

Reclassify Vegetation

Change Symbology

Edit Layer Title

Convert Raster to Vector

Convert Raster to Vector

Convert Raster to Vector

Raster Polygon

Change Symbology

Double click on layer or go to layer properties

Change Symbology

Change Symbology

Change Symbology

Change Symbology

Double click on symbol, choose more symbols

Change Symbology

Create Map

Completing LAB 2

• Do NOT follow directions to upgrade the data (we are using 9.1) unless in TA room

• Create a Map of the Reclassified Vegetation (Drought Sensitivity) Vector Data – use nice symbology to make it clear and make a nice map (email or print)

• Email or print Spatial Analysis Module1 Completion Certificate

• Due Friday April 27th

Next Class

• Working with Survey Data in ArcGIS