tutor81 vol i

8/12/2019 Tutor81 Vol i

1/67

8/12/2019 Tutor81 Vol i

2/67

8/12/2019 Tutor81 Vol i

3/67

WMS 8.1 Tutorials Volume 1

Copyright 2008 Aquaveo, LLC

All Rights Reserved

Unauthorized duplication of the WMS software or documentation is strictly prohibited.

AQUAVEO LLC MAKES NO WARRANTIES EITHER EXPRESS OR

IMPLIED REGARDING THE PROGRAM WMS AND ITS FITNESS FORANY PARTICULAR PURPOSE OR THE VALIDITY OF THEINFORMATION CONTAINED IN THIS USER'S MANUAL

The software WMS is a product of the Aquaveo, LLC. For more informationabout this software and related products, contact Aquaveo at:

Aquaveo75 South 200 East, Suite 201Provo, Utah 84606Tel.: (801) 691-5528e-mail: [email protected]: http://www.aquaveo.com/

For technical support, contact Aquaveos tech support number at (801) 691-5530 (Monday-Friday, 8am-5pm Mountain Time)

8/12/2019 Tutor81 Vol i

4/67

TABLE OF CONTENTS

1 INTRODUCTION ................................................................................................................................... 1-1 1.1 EXERCISE FILES ................................................................................................................................. 1-1 1.2 STARTING OVER ...................................... .......................................................................................... 1-1 1.3 GETTING AROUND THE WMS I NTERFACE .......................................................................................... 1-2

2 IMAGES................................................................................................................................................... 2-1 2.1 OBJECTIVES .... ................................................................................................................................... 2-1 2.2 GEOTIFF FILES ................................................................................................................................... 2-2 2.3 WORLD FILES ......... ...........................................................................................................................2-3 2.4 IMAGE R ESOLUTION ........................................................................................................................... 2-4 2.5 BUILDING PYRAMIDS ................. ........................................................................................................ 2-5 2.6 R EGISTERING SCANN ED IMAGES ........................................................................................................ 2-6 2.7 I NTERNET EXERCISES ....................................................................................................................... 2-10 2.8 CONCLUSION .................................................................................................................................... 2-12

3 BASIC FEATURE OBJECTS................................................................................................................ 3-1 3.1 OBJECTIVES ................................................. ...................................................................................... 3-1 3.2 CREATING AND EDITING FEATURE OBJECTS .......... ............................................................................ 3-2 3.3 USING SHAPEFILES TO CREATE FEATURE OBJECTS ................ ............................................................ 3-6 3.4 CREATING FEATURE OBJECTS USING BACKGROUND IMAGES ............................................................ 3-8 3.5 MORE FEATURE OBJECTS FROM IMAGES ......................................................................................... 3-11 3.6 DISPLAY OPTIONS ............................................................................................................................3-11 3.7 CONCLUSION .................................................................................................................................... 3-12

4 DEM BASICS........................................................................................................................................... 4-1 4.1 OBJECTIVES ....................................... ................................................................................................4-1 4.2 GETTING DEM S FROM THE I NTERNET ................................................................................................4-2 4.3 MERGING DEM S................................................................................................................................4-5 4.4 TRIMMING DEM S ..............................................................................................................................4-6 4.5 DISPLAYING DEM S............................................................................................................................4-7 4.6 CONCLUSION ...................................................................................................................................... 4-9

5 USING TRIANGULATED IRREGULAR NETWORKS ................................................................... 5-1 5.1 OBJECTIVES ...................... ................................................................................................................. 5-1 5.2 IMPORTING SURVEY DATA ................................................................................................................. 5-2 5.3 GETTING A BACK GROUND IMAGE ...................................................................................................... 5-2 5.4 DIGITIZING DATA ..................... .......................................................................................................... 5-3 5.5 CONVERTING CAD DATA TO A TIN................................................................................................... 5-4 5.6 TRIANGULATION ................ ................................................................................................................5-4 5.7 AUTOMATED TIN EDITING .................................. .............................................................................. 5-5 5.8 CREATING A TIN USING A CONCEPTUAL MODEL .............................................................................. 5-6 5.9 CONVERT TO DEM ... ......................................................................................................................... 5-9 5.10 EXPORTING DATA TO CAD.............................................................................................................. 5-10

6 ADVANCED FEATURE OBJECTS ..................................................................................................... 6-1

8/12/2019 Tutor81 Vol i

5/67

6.1 OBJECTIVES ....................................................................................................................................... 6-1 6.2 DEFINING A WATERSHED W ITH FEATURE OBJECTS ........................................................................... 6-1 6.3 MORE BASIN DELINEATION ............... ................................................................................................ 6-5 6.4 FEATURE OBJECTS FROM CAD DATA ................................................................................................ 6-8 6.5 CONCLUSION ..................................................................................................................................... 6-9

8/12/2019 Tutor81 Vol i

6/67

8/12/2019 Tutor81 Vol i

7/67

1 Introduction

CHAPTER 1

Introduction

In this first exercise you will get familiar with the WMS interface and helpsystem. You should explore the different menus, modules and tools so that youhave a good idea of the organization.

1.1 Exercise Files

Each exercise has one or more files that have been prepared for you to use.You are instructed at various points to open these files. The default installationof WMS copies all of these files into a directory named tutorial (forexample you will find them in C:\Program Files\WMS81\tutorial if youinstalled WMS in the default folder of C:\Program Files\WMS81 ). Further, thefiles for each exercise are organized by directory within the tutorial directory.Directories are named with abbreviations for the chapter name and the firsttime you open a file for each exercise you will be directed to open from theappropriate folder in the tutorial directory. Remaining files for a given exercisewill be located in the same directory.

1.2 Starting OverIt is suggested that you start WMS new at the beginning of each exercise. Ifyou continue from one to another without quitting, then data, display options,and other WMS settings may not be in sync with the instructions, and may leadto confusion.

8/12/2019 Tutor81 Vol i

8/67

1-2 WMS Tutorials Volume 1

1.3 Getting Around the WMS InterfaceThe WMS Help file has a section on some of the basic elements of the WMSgraphical user interface (GUI). The demonstration portion of this lesson

covered most of the basic elements of the Quick Tour, but it is contained in theWMS Help file should you want to review later.

1.3.1 Self-Guided Tour

The WMS Help file is located at http://www.xmswiki.com and contains basicinformation for some of the important elements of the GUI. In this section youshould review these help pages and then practice on your own to understandhow the interface works.

1. Start WMS

2. Select Help | WMS Help

3. Review these sections and then close the help page

4. Select File | Open

5. Locate the folder C:\Program Files\WMS81\tutorial\demedit

6. Open the file named trailmount.dem

7. Select OK


9. Open the file named trailmountain.tif

10. Select No if asked to convert your TIFF to a JPEG

As a minimum be sure that you are comfortable with the following operationswithin the WMS interface (if you have questions, search on the topic inside theWMS help page for further explanation):

Switching modules

Switching tools

Zooming, panning, framing the image, and rotating in 3D

When you are finished, use the Plan View macro to make sureyou are in plan view before trying other things
http://www.xmswiki.com/http://www.xmswiki.com/

8/12/2019 Tutor81 Vol i

9/67

0BIntrodu ction 1-3

Using the Display Options , Contour Options , and othermacros

Turning objects on and off and accessing menus from the Project

Explorer

Changing Display Options

Adjusting Contour Options

Saving a project file

Continue exploring the different elements of the interface and/or reviewing theinformation within the WMS Help page.

8/12/2019 Tutor81 Vol i

10/67

8/12/2019 Tutor81 Vol i

11/67

2 Images

CHAPTER 2

Images

Images are an important part of most projects developed using WMS. Animage is comprised of a number of pixels (picture elements), each with its owncolor. The resolution, or size, of the pixels will determine the amount of areaand detail represented in the image. Images are used in WMS to derive datasuch as roads, streams, confluences, land use, soils, etc. as well as providing a

base map or backdrop to your watershed. In order to make use of imagesthey must be georeferenced. Georeferencing an image defines appropriate xand y coordinates so that distances and areas computed from the image will beaccurate. Because images are commonly used in Geographic InformationSystem (GIS) programs like WMS, data developers often store thegeoreferencing information as either part of the image file (a geotiff file forexample), or in a separate file commonly referred to as a world file.

2.1 ObjectivesIn this exercise you will learn the primary ways that images are imported andgeoreferenced, or registered, by WMS. You will:

1.

Learn how to use geotiff files2. Learn how to use world files

3. Learn about image resolution

4. Learn how building pyramids affects image display

5. Learn how to register scanned images

8/12/2019 Tutor81 Vol i

12/67


6. Learn how to download images using the Internet

2.2 Geotiff FilesGeotiff images are files that store georeferencing information. This means thatyou do not have to specify coordinates when you read in the image it is donefor you automatically. You will also see how you can tile multiple imagestogether.

2.2.1 Setting Preferences

1. Close all instances of WMS

2. Open WMS

3. Right-click in the Project Explorer below the tree contents and select Preferences in the pop-up menu that appears (or select Edit | Preferences )

4. Select the Image Preferences tab in the Preferences dialog

5. Verify that Image Pyramids is set to Always Build

6. Under TIFF->JPEG Conversion, make sure Convert to JPEG is set to Never Convert

7. Select OK

2.2.2 Tiling Images


2. Locate the folder C:\Program Files\WMS81\tutorial\images

3. Open redridge.tif

4. Right-click on the redridge image icon in the Project Explorer andchoose the Crop Collar command

5. Choose the Zoom tool

6. Single-click on the image to zoom in

7. Keep zooming in until the display of the image is clear

8. Select the Frame macro

8/12/2019 Tutor81 Vol i

13/67

1BImages 2-3


10. Open josephspeak.tif (This is an adjacent 1:24000 map image.)

11. Right-click on the josephspeak image icon in the Project Explorer andchoose the Crop Collar command

12. Try zooming in and see if you can see where the map seams are(hopefully you will have some difficulty, but if you look close enoughyou may be able to tell)


2.3 World Files

Many image files do not contain georeferencing information. For exampleJPEG files do not have georeferencing tags in the file like TIFF images mayhave. Most organizations that make images available for use distribute worldfiles containing the georeferencing information along with the image files.These world files usually have the same name as the corresponding TIFF orJPEG file, but with the extension .tfw (for JPEG files the extension is .jgw, or.jpgw). If you download a world file and are asked to supply a name for it,follow this naming convention. Use the following procedure to open a JPEGfile and its corresponding georeferencing information in WMS:

1. Select File | New

2. Select No when asked if you want to save your changes


4. Open richfield1.jpg

Because there is a world file named richfield1.jpgw the image is automaticallyregistered. If a world file for an image is not named with the .tfw (or for aJPEG it is not .jgw or jpgw) then you would have the option of importing theworld file from within the registration dialog.

The Richfield image file was obtained from the TerraServer

(http://terraserver.microsoft.com ), along with the world file. You can getmultiple images and tile them together as illustrated in the next few steps. This

process will illustrate how properly georeferenced files overlap automatically(e.g. without the tediousness associated with tiling images). Thus, it is notnecessary to be exact in obtaining images and files from a terrserver source;overlapping is not a problem.

http://terraserver.microsoft.com/http://terraserver.microsoft.com/

8/12/2019 Tutor81 Vol i

14/67


6. Open richfield2.jpg


8.

Open richfield3.jpgYou can zoom or pan and turn on/off the different images to explore how theycan be viewed and used when overlapping.

2.4 Image ResolutionImages are usually available in different resolutions. In this part of the exerciseyou will open topographic maps of the same area at different resolutions.




4. Open tm4m.jpg

5. Use the Zoom tool to zoom in on the image until you can see theindividual pixels of the image


7. Open tm16m.jpg

8. Select Display | View | Previous View

9. In the Project Explorer toggle the display of tm16m on and off to seethe difference in resolution of the two images


11. Open tm32m.jpg

12. Zoom in and toggle the display of the images on and off in order toobserve and compare the resolutions of all three images

When you zoomed in on the three images, you may have noticed that as themap scale increased, the map showed less detail. tm4m shows much moredetail than either tm16m or tm32m . Images are commonly available on ascale of 1:24000, 1:100000, or 1:25000. 1:24000 maps cover far less area than1:100000 or 1:250000 maps, but they show much more detail (higherresolution). It would take thirty-two 1:24000 maps to cover the same area thatis covered by one 1:100000 map. If you need a great amount of detail for your

8/12/2019 Tutor81 Vol i

15/67

1BImages 2-5

watershed, you may want to use the 1:24000 maps. However, if your watershedis very large, this size of map will provide too much detail. Thus, it would bedifficult to see the big picture of your watershed, and a 1:100000 or1:250000 scale map may be more appropriate.

2.5 Building PyramidsWMS 8.1 provides the option of building pyramids when each image file isopened. When pyramids are built multiple files of varying resolutions are saved

by WMS so that when a large area of an image is viewed a lower, or coarser,resolution image is displayed. A higher, or finer, resolution image is displayedas you zoom in to view a smaller portion of the image. This is similar to anautomatic resampling process. On the other hand, when image pyramids are not

built, only the original resolution image is displayed.

The advantages of building pyramids include faster and clearer display of animage. Image display is faster due to lower resolution images being displayedfor larger areas and higher resolution images being displayed for smaller areas.The clarity of image display improves in situations when the image resolutionexceeds the display resolution of the screen, which often occurs as you view alarge portion of a high resolution image.

Because WMS only builds pyramids for JPEG images you must convert TIFFimages to the JPEG format in order to build pyramids. Image conversion can

be performed by WMS either as you open the image or after opening theimage. By default, WMS always builds pyramids when a JPEG image isopened or created through conversion. Nevertheless, this setting can be

changed. In order to best see the difference between images with and without pyramids built, we will alter the default settings as follows:



3. Under Image Pyramids, select Prompt for Each Image

4. Under TIFF->JPEG Conversion, ensure that Convert to JPEG is set to

Always Convert , and Save JPEG is set to Temporary Folder 5. Select OK

With the default image pyramids settings set, we are ready to examine thedifferences between building and not building pyramids. We will begin byopening a 1:24000 USGS quadrangle map without building pyramids, asfollows:

8/12/2019 Tutor81 Vol i

16/67




8. Select File | Open 9. Open redridge.tif

The image is automatically converted from a TIFF image to a JPEG image based on the Image Preferences. This procedure may take a little bit of time.

10. Select Yes to build pyramids in the image pyramids inquiry

Notice the clarity of this topographic map. To see the differences associatedwith image pyramids, we will open the same file but will not build pyramids.


12. Select No if asked to save changes

13. Open redridge.tif

14. Select No on the image pyramids inquiry

Notice that the contours of the topographic map are not as clearly defined, andthat the overall look of the image is grainy when compared to when pyramidswere built. Now we will reset the default image preferences.



17. Under Image Pyramids, select Always Build

18. Under TIFF->JPEG Conversion, ensure that Convert to JPEG is set to Never Convert , and Save JPEG is set to Temporary Folder

19. Select OK

2.6 Registering Scanned ImagesSometimes you will not be able to obtain a geotiff image or an image with aworld file. In this case, you will need to register the image manually. To dothis, you will need to know the coordinates of three points on the image. Thesecoordinates can be in a projected or geographic system. Before you scan your

paper image, or download an image from the Internet, you will want to mark

8/12/2019 Tutor81 Vol i

17/67

1BImages 2-7

the three points you have selected so that you can easily find the points on theimage when you register the image in WMS.

We will use a part of a soils file as a scanned image that will be used later todevelop a soils coverage and then later to compute a composite curve number.


2. Select No if asked if you want to save your changes


4. Open soils.tif

An image representing soil types will appear in the Register Image dialog.Three small red X's are marked on the image (these are small and may be

difficult to see). There are also three plus signs with the numbers 1, 2, and 3 bythem (much larger and visible). You need to place the numbered plus signsover the small xs and enter the appropriate coordinates in order to register theimage.

5. Use the Point Selection tool to drag each red + over thecorresponding X as shown in Figure 2-1 . You may wish to place themclose and then zoom in on the area for more accuracy. Once you zoomin there is a Frame tool that you can use to re-center the image so thatyou can zoom in on another registration point. Do your best to moveeach plus mark over the corresponding red X in the image.

8/12/2019 Tutor81 Vol i

18/67


Figure 2-1: Moving + Marks in Registration Dialog

2.6.1 Registering in Geographic Coordinates

The coordinates for the three points are known in geographic(latitude/longitude) and so we will register using these coordinates and thenconvert to UTM afterwards. You can use the Convert Point dialog from theEdit menu to enter degrees-minutes-seconds and convert to decimal degrees ifnecessary, but in order to properly register the coordinates must be decimaldegrees. Also you will notice that longitude values west of the prime meridianshould be entered as negative.

1. Using the values listed in Table 2-1 to enter the appropriate x(longitude) and y (latitude) values for the three points

Table 2-1: Latitude and Longitude for soils.tif

Point Longitude (x) Latitude (y)1 -112.481944 38.685002 -112.477222 38.576673 -112.330277 38.57611

8/12/2019 Tutor81 Vol i

19/67

1BImages 2-9

2. When you have correctly entered the three coordinates select OK in theRegister Image dialog


If the image appears distorted or crooked, you may have entered thecoordinates incorrectly or placed the + marks inaccurately

2.6.2 Converting the Coordinates to UTM

Geographic coordinates are commonly used on maps because they provide aglobal reference for any point in the world. However, for engineering work a

planimetric system is necessary. The Universal Transverse Mercator (UTM) projection is commonly used so we will convert the coordinate system fromgeographic to UTM.

1. Right-click on the soils image icon in the Project Explorer and choosethe Coordinate Conversion option

2. Select Geographic NAD 83(US) from the Convert From: HorizontalSystem: drop down box

3. Set the Vertical System units to Meters

4. Toggle on the Edit Project Coordinate System check box

5. Select UTM NAD 83(US) from the Convert To: Horizontal System:drop down box

6. Set the Horizontal Units field to Meters

7. Set the Vertical System Units to Meters

8. Select OK

8/12/2019 Tutor81 Vol i

20/67


There is some distortion in the image as it is converted from geographic toUTM because a degree of longitude has a shorter distance the farther north youare, but this is normal. Any measurements taken now, or data created from theimage, will have meters for coordinate values.

2.7 Internet ExercisesThe Internet contains many useful locations where images and other usefulWMS modeling data can be downloaded. Any location that has a picture or animage of a map can provide useful information within WMS. The next twosections require Internet access and will give you practice downloading imagesand registering them for use in WMS.

2.7.1 Download Images from the TerraServer

The Environmental Modeling Research Laboratory maintains an Internet sitethat points users to helpful data download locations. This site is found at:http://emrl.byu.edu/gsda . One of the sections on this page is to download DRGImages (maps and aerial photographs). Choose this option and then go to theTerraServer.

The TerraServer provides you with options to search by address, city, orclicking interactively on a map. Download a topographic map and/or aerial

photograph for a location of interest (your hometown if nothing else comes tomind). Do not forget to get the world file. You can find help on the GSDAwebsite.

After you download your images make sure you can open them correctly inWMS.

2.7.2 The TerraServer and Web Services

Recent advances in programming technologies include the possibility ofrunning program DLLs from remote sites. This utility is called webservices,and the TerraServer includes a web service that WMS can call to download

both image and world files directly. Because the TerraServer prepares worldfiles in UTM NAD 83 it is important that the current coordinate system inWMS be defined to something other than Local so that WMS can perform any

necessary coordinate conversions. For this example you will load a portion of aDEM, convert the coordinates to UTM NAD83 and then use web services todownload the topographic map and aerial photograph images.


http://emrl.byu.edu/gsdahttp://emrl.byu.edu/gsda

8/12/2019 Tutor81 Vol i

21/67

1BImages 2-11


4. Locate the folder C:\Program Files\WMS81\tutorial\dembasics\NED

5.

Find and open the file named ned_Richfield.hdr 6. Select OK to import the NED DEM file

7. Select Yes to convert the coordinates of the DEM from geographic to a planimetric system

8. Select Geographic NAD 83(US) from the Convert From: HorizontalSystem: drop down box

9. Set the Vertical System units to Meters

10. Toggle on the Edit Project Coordinate System check box

11. Select UTM NAD 83(US) from the Convert To: Horizontal System:drop down box

12. Set the Horizontal Units field to Meters

13. Set the Vertical System Units to Meters

14. Select OK

You should now have a portion of DEM contoured and displayed. You willnow load the topographic and aerial photograph images directly from the

TerraServer.

15. Select the Get Data tool

16. Drag a box around the extents of the contoured DEM to define theregion you wish to download the image

17. Select the Web Services option

18. Turn on the TerraServer aerial photo and TerraServer topo options

19. Select OK

20. Define the name of the web files to be CC

21. Select OK

22. Select Yes to accept the default file naming convention for web files

23. Accept the suggested resolution of the images by selecting OK

8/12/2019 Tutor81 Vol i

22/67


24. Be patient; it may take 30 seconds to a minute to complete thedownload process. When it does complete you will see the aerial

photograph for the box defined in the graphics window (hopefullycovering the entire DEM area).

When finished the topographic map will come in on top of the aerial photograph, but you may control which one is displayed using their respectivecheck boxes in the Project Explorer window. The lower the resolution the moredetail you will see. You can go to a higher resolution than suggested but if youwant a high resolution for a large area it could take several minutes todownload (you should probably not try to get a higher resolution than one ortwo more levels than suggested).

2.8 Conclusion

In this exercise, you were taught how to open several types of images in WMS.You learned how to georeference images and build pyramids for displayingimages. In particular, you should know:

1. How to use geotiff files

2. How to use world files

3. How to build pyramids

4. How to register images

8/12/2019 Tutor81 Vol i

23/67

3 Basic Feature Objects

CHAPTER 3

Basic Feature Objects

Feature objects are points, lines, and polygons organized in coverages bydifferent attribute sets such as drainage features, land use, soils, time travel

paths, cross sections, etc. The primary coverage in WMS is the drainagecoverage, which holds drainage boundary polygons, stream lines, and outletnodes. Most of the other coverages are secondary to the drainage coverage andare used to map other hydrologic parameters such as travel time or curvenumbers. Feature objects are equivalent to GIS vector data, therefore,importing from GIS databases is one important way to create coverages inWMS. Another important method for creating feature object coverages is todigitize directly from the screen, using a georeferenced image in the

background as a guide. In this exercise you will experiment with both methods,with the main focus being the use of the various tools and assigning attributes.

3.1 ObjectivesIn this exercise you will learn the basics for creating and importing featureobjects and managing different coverages. This includes the following:

1.

Creating and editing feature objects2. Defining feature object attributes

3. Creating coverages and specifying attribute sets

4. Using shapefiles

5. Using images to create feature objects

8/12/2019 Tutor81 Vol i

24/67


6. Managing multiple coverages

3.2 Creating and Editing Feature ObjectsThe Terrain Data, Drainage, and Map modules are where the feature objects arecreated and manipulated. All feature objects are made from a set of points andthe lines connecting the points. There are three main types of feature objects:

points, arcs, and polygons. The following steps will teach you how to createand edit the different types of feature objects.


2. Open WMS

3. Switch to the Map module


5. Locate the folder C:\Program Files\WMS81\tutorial\feature

6. Open FeatureObjects.img

This is just a picture of feature objects that you will use to trace and createfeature objects. Do not be confused that it already looks like the featureobjects are created.

3.2.1 Creating Feature Arcs1. Find the portion of the image labeled Vertices, Nodes, and Arcs

2. Choose the Create Feature Arc tool

3. Single-click on the image near the point labeled 1

4. Double-click on the image near point 2 to end the arc

While you are creating a feature arc, you can press Esc to cancel, Backspace to back up one vertex, Enter or single-click to make a vertex, and double-click toend the arc. When WMS creates an arc, each end is a node and all points in themiddle are vertices.

5. Single-click at point 3, directly on top of the arc you just made

6. Double-click at point 4 to end the arc

7. Single-click at point 5

8/12/2019 Tutor81 Vol i

25/67

2BBasic Feature Objects 3-3

8. Double-click at point 6

Notice how WMS automatically links the new arc to the existing arc andcreates a node at the point of intersection.

3.2.2 Inserting Vertices and Snapping Arcs

Oftentimes you will have two arcs very close to each other that should share acommon node, but do not. WMS has an option to snap these nodes together.

1. Choose the Create Feature Vertex tool

2. Single-click on the arc where it is labeled 7

A vertex is inserted here just as if you had clicked here when creating the arcoriginally. You must create a vertex at this location so that the arc can besnapped to this location.

3. Choose the Select Feature Point/Node tool

4. Right-click on the node labeled 5 and select Clean on the pop-upmenu.

5. Make sure the Snap selected nodes option is checked

6. Select OK

At the bottom of the WMS screen, you will notice the help script is prompting

you to select a snapping point.

7. Select the vertex you just created (labeled 7).

WMS snaps the two arcs together and changes the vertex at point 7 to a node.

3.2.3 Deleting a Portion of an Arc

Now that the main arc you created has two nodes along its length, you candelete the center portion only.

1. Choose the Select Feature Arc tool

2. Select the portion of the arc between nodes 3 and 7

3. Press the DELETE key, or right click and select Delete, to delete thearc

4. Select OK

8/12/2019 Tutor81 Vol i

26/67


You can also create arcs between two existing nodes. Practice this byreforming the arc that you just deleted.


6. Click on the node labeled 3

7. Click on the node labeled 7 to re-form the arc

3.2.4 Converting Vertices to Nodes

WMS uses vertices and nodes for different purposes. For example nodes canhave attributes while vertices simply define the shape or position of the arc.Sometimes you will need to change a vertex to a node or a node to a vertex.

1. Choose the Create Feature Vertex tool

2. Click on the arc somewhere between nodes 3 and 7

3. Choose the Select Feature Vertex tool

4. Right-click on the vertex you just made and select Vertex Node onthe pop-up menu.

You should now see a red node at this location. You have effectively brokenthe arc in half. You have also made it possible to define attributes (e.g. adrainage outlet) at this location.

3.2.5 Converting Nodes to Vertices

Just as you can change vertices to nodes, you can change nodes to vertices. It isnot necessary in most cases to do this, but can leave you with a cleanerrepresentation of your feature arcs. For example you now have to manage andassign attributes to one arc instead of two because converting a vertex to a nodemerges two arcs together.


2. Right-click on the node you just converted and select Node Vertex

on the pop-up menu.

You can see that the node has been changed back to a vertex.

3.2.6 Building Polygons

Find the portion of the image labeled Polygons.

8/12/2019 Tutor81 Vol i

27/67



2. Single-click at the point labeled 1 on polygon A

3.

Single-click on points 2 through 104. Single-click on point 1 again to end

5. Trace polygon B in the same manner

You should now have two closed loops made out of the arcs just created. Theyare not polygons at this time they are still just arcs.

6. Right-click on the Drainage coverage and select Build Polygon on the pop-up menu.

7. Select OK to use all the arcs

The two polygons should now be drawn with a thick line instead of the thinnerarc lines. Polygons are built from their constituent arcs and it is during the

build polygon function that the appropriate topology is established.

3.2.7 Assigning Attributes

Each of the nodes, arcs, and polygons you created were created with default properties or attributes. WMS allows you to change the attributes of featureobjects.

1. Choose the Select Feature Arc Tool

2. While holding the SHIFT key down, select (multi-select) all 5 arcsections in the Vertices, Nodes, and Arcs portion of the image

3. Select Feature Objects | Attributes

A dialog will come up allowing you to choose whether you want the arcs tohave the Generic, Stream, Pipe, Lake, or Ridge attribute.

4. Select the Stream option

5.

Select OK

The arcs should now be colored blue. Each arc portion should have a small blue arrow on it. These arrows show the way the stream you have createdflows. The original direction you created the arc determines the way the streamflows now. Stream arcs should always be created from downstream toupstream. You should also be able to see that the lower node on the arc looksdifferent now. WMS has automatically changed it to a drainage outlet insteadof a generic node.

8/12/2019 Tutor81 Vol i

28/67



7. Double-click on the lower node (now an outlet)

A dialog comes up showing that the node now has the Drainage outlet attribute.For any feature object (point, line, arc) you can select and then choose theAttributes command from the Feature Objects menu, or double-click to bringup the attributes dialog.

8. Select OK

Just as you can change the attributes of arcs and nodes, you can change theattributes of polygons.

9. Choose the Select Feature Polygon tool

10. Double-click anywhere inside Polygon A in the polygons portion ofthe image

11. Select the Drainage boundary type

12. Select OK

Polygon A should now be drawn in a thick colored line.

13. Double-click anywhere inside Polygon B

14. Select the Lake/Reservoir type

15. Select OK

Polygon B should now be drawn in light blue.

3.3 Using Shapefiles to Create Feature ObjectsOne of the most important features of WMS is the ability to automaticallycreate feature objects using shapefiles.



You will import shapefile data differently depending on whether the computeryou are working on has ArcView installed on it or not. For this exercise, thetwo ways are basically equivalent. However, if you have ArcView installed,you have access to more data types and display options.

8/12/2019 Tutor81 Vol i

29/67


3.3.1 Importing a Shapefile and Mapping to Feature Objects

1. Right-click on GIS Layers in the Project Explorer and select AddShapefile data.

2. Open streams.shp

In order for the shapefile to work correctly, streams.dbf and streams.shx must be located in the same directory as streams.shp . This is true for all shapefiles.

3. Choose the Select Shapes tool

4. Draw a box around all the shapes to select them all

5. Select Mapping | Shapes -> Feature Objects

This is the GIS to Feature Objects Wizard. It is used to map shapefile data tofeature objects in WMS.

6. Choose Next

The spreadsheet that is presented shows each shapefile attribute in capitalizedletters. In this file, you should see DRAINTYPE, LENGTH, SLOPE, etc.Underneath each attribute is a dropdown box containing the WMS attributesyou can choose to map the shapefile attributes to.

7. The DRAINTYPE attribute should be mapped to Drainage Arc type

8. The LENGTH attribute should be mapped to Stream length

9. The SLOPE attribute should be mapped to Stream slope

10. The DMANNINGS attribute should not be mapped ( Not mapped )

This attribute cannot be mapped because there is not a corresponding WMSattribute available to map it to.

11. The BASINID attribute should be mapped to Stream basin id

You can scroll through the mapping spreadsheet to see the value that isassigned to each attribute for each shape.

12. Click Next

13. Click Finish

14. Toggle off the streams.shp shapefile in the Project Explorer to seeresult of mapping the shapefile to WMS feature objects.

8/12/2019 Tutor81 Vol i

30/67


You have now imported a shapefile containing streams and basins, convertedall the shapes to WMS feature objects, and mapped data from the originalshapefile to WMS attributes.

3.4 Creating Feature Objects Using Background ImagesAnother important feature of WMS is the ability to create feature objects using

background images as guides. For instance, you may have a soil use map youwant to read into WMS. The following procedure explains how this is done.

3.4.1 The Project Explorer

First, you will need to create a new coverage by utilizing the Project Exploreron the left hand side of the WMS main window.

The Project Explorer displays and allows users to manage the currentcoverages and data in WMS.


2. Select No if asked if you want to save your changes

In the Project Explorer, you should see a folder entitled Map Data . You shouldalso see the default coverage listed (always a Drainage coverage when

beginning a new project) in the Coverages folder. From the Project Explorer,you can manage the default coverage, make new coverages, delete coverages,edit coverage properties, and change the active coverage.

3. Right-click on the existing coverage in the Project Explorer, named Drainage

4. Select Rename

5. Enter PracticeDrainage for the new coverage name

6. Right-click on the Coverages folder

7. Select New Coverage

8. From the Coverage type dropdown box, select Soil Type

9. Notice that the coverage name is automatically changed to Soil Type

10. Select OK

11. Click on the PracticeDrainage coverage

8/12/2019 Tutor81 Vol i

31/67


You can see that this coverage shows up in color and bold, while the Soil Typedrainage is in gray and regular font. This means that the PracticeDrainage coverage is the active coverage.

12. Select the Soil Type coverage to make it active

13. Uncheck the box next to the PracticeDrainage coverage

14. Now the PracticeDrainage coverage is not visible. Turn this coverage back on to make it visible again.

3.4.2 Reading in Images

Now that you have added a soil type coverage, you can read in the soils image.


2. Open soils.img

3.4.3 Manually Digitizing Feature Objects


2. Make sure that the Soil Type coverage is selected

3. Starting anywhere on the border of the large orange area, outline theentire region, labeled D, with an arc

You can be as accurate as you like. If you wish, you can even zoom in to get acloser view of the image. You will have to end the arc by double-clicking inorder to be able to select any other tools, such as zoom, pan, or show all. Onceyou have zoomed to the location you want, you can just pick up where you leftoff. Remember that when you click near an existing vertex or arc, WMS willautomatically snap the new arc to the existing one.

4. Outline all the other soil type polygons similarly, without creating arcson top of previously defined borders

NOTE: When outlining the other regions, simply start somewhere on the previously created arc and proceed around a border without re-drawing whereanother border has already been defined by arcs.

5. Right-click on the Soil Type coverage and select Build Polygon

6. Select OK to use all the arcs

8/12/2019 Tutor81 Vol i

32/67


Check to make sure that each soil use polygon is completely outlined. If one ormore polygons do not build correctly, check to be sure that the arcssurrounding the polygons are completely closed.

3.4.4 Assigning Feature Polygon Attributes

Now that you have created the soil use polygons, you will need to assign thesoil use attributes to the correct polygons.

1. Choose the Select Feature Polygon tool

2. Double-click on the yellow polygon labeled B

The Soil type mapping dialog should come up automatically. Just as in the first part of the exercise, double-clicking on a feature object brings up a dialogallowing you to select or edit its attributes. Since you are now using a Soil Type coverage, the automatic attribute for a polygon is Soil Type.

3. Choose the Add soil ID to list button

4. Choose this button two more times, so that there are four soil types inthe list box

We will now assign soil types to the WMS Soil IDs.

5. Under Soil type properties, notice the drop-down buttons used toassign relationships to the Soil IDs

6. Soil ID 0 should be assigned to Soil Type A

7. Soil ID 1 should be assigned to Soil Type B

8. Soil ID 2 should be assigned to Soil Type C

9. Soil ID 3 should be assigned to Soil Type D

10. Since the polygon we clicked on originally is Type B, select Soil ID 1 from the WMS soil ID list and choose the Apply button

11. Double-click on the polygon labeled A

12. Select Soil ID 0 from the WMS soil ID list and choose Apply

13. Similarly, assign Soil ID 2 to all the polygons labeled C and Soil ID 3to all the polygons labeled D

14. Make sure each polygon has the proper Soil ID assigned by double-clicking on each and checking the soil type in the Selected SoilProperties box

8/12/2019 Tutor81 Vol i

33/67


3.5 More Feature Objects from ImagesWMS handles land use images the same as it does soil type images. You willnow read in a land use image, digitize polygons, and assign land uses. You

need the land use image (and the resulting land use polygons) to be on its owncoverage, so you will need to create a land use coverage.

1. Right-click on the Coverages folder in the Project Explorer

2. Select New Coverage

3. From the Coverage type dropdown box, select Land Use

4. Select OK

Usually you would open the land use image and digitize the land use polygonsyourself. Here, you will open a completed file. To use the completed file,complete the following steps:


6. Open luse.map

If you were digitizing the image yourself, you would complete the followingsteps:

1. Select Images | Import

2. Open luse.img

As outlined in Parts 3.4.3 and 3.4.4 , you would trace all the land use polygonswith arc segments (while in the Map module), build polygons, and then mapthe land use IDs to the correct polygons.

3.6 Display OptionsWMS has many display options to help you tailor the look of your project toyour needs. You can change options such as polygon colors, presence of nodesand vertices, and legends using the Display Options command.

1. Right-click on the Soil Type coverage and select Display Options onthe pop-up menu.

2. On the Map tab, check the Color Fill Polygons box

3. Uncheck the Points/Nodes and Vertices boxes

8/12/2019 Tutor81 Vol i

34/67


4. Choose the Soil Type Display Options button at the bottom of thespreadsheet

5. Select the first Soil ID listed in the list box and click on the colorsquare to the right

6. Choose a new color from the color palette

7. Change the colors of the other soil groups uses if you desire

8. Select OK

9. Check the Soil Type Legend box

10. Select OK once again to exit the Display Options dialog

You can continue to explore the display options if you wish. If you wanted toassign new colors to the land uses, you would need to make the land usecoverage active before going back into the Display Options dialog or switch toLand Use in the coverage type combobox

3.6.1 Managing Coverages

Using the Project Explorer, you can choose to hide and/or show coverages anddesignate which coverage is the active coverage

1. From the Project Explorer, toggle off the check boxes for thePracticeDrainage and the Soil Type coverages

2. Click on the land use coverage so it will be active

Now only the land use coverage will be visible on the screen. The othercoverages still exist; they simply will not show on the screen until you turntheir visibility back on.

3.7 ConclusionIn this exercise you should have learned the basics for creating and importingfeature objects and managing different coverages. Both these concepts are

central to your understanding of WMS. You should now be able to:

1. Create and edit feature objects

2. Set feature object attributes

3. Create coverages and specify coverage attribute sets

4. Import shapefiles

8/12/2019 Tutor81 Vol i

35/67


5. Use images to create feature objects

6. Manage multiple coverages

7. Import and edit feature objects from DXF data

8/12/2019 Tutor81 Vol i

36/67

8/12/2019 Tutor81 Vol i

37/67

4 DEM Basics

CHAPTER 4

DEM Basics

Digital Elevation Models (DEMs) are the most commonly available digitalelevation source and therefore an important part of using WMS for watershedcharacterization. A DEM is a rigid data structure that contains a two-dimensional array of elevations where the spacing between elevations isconstant in the x and y directions. In the US, DEMs are downloadable from theInternet at 30-meter (1:24,000 map series) and 90-meter (1:250000 map series)resolutions. The USGS has recently deployed the National Elevation Datasetwhich is a continuous elevation map at 30-meter resolution. Blocks of 100 MBor less can be downloaded for free from the NED website.

The Arc/Info ASCII grid format is common throughout the GIS world and iscommon outside the US. The basics of downloading, importing, editing, anddisplaying DEMs will be demonstrated in this exercise. Actually using theDEM for watershed delineation is the subject of the next chapter.

4.1 ObjectivesIn this exercise you will learn the basics of importing, viewing and preparing

DEMs for automated watershed delineation. This includes the following:1. Importing USGS DEMs from different formats

2. Tiling multiple DEMs together

3. Editing DEM elevations

4. Setting DEM display options

8/12/2019 Tutor81 Vol i

38/67


4.2 Getting DEMs from the InternetIn this part of the exercise, you will learn how to download DEM data from the

National Elevation Dataset website at http://ned.usgs.gov/. Instead of

bookmarking this site, you can bookmark the GeoSpatial Data Acquisition(GSDA) homepage: http://xmswiki.com/index.php?title=GSDA:GSDA. Thissite contains links to this and many other sites where you can get DEM data.

If you do not have an Internet connection you can still work through thisexercise using the files which have been downloaded already and placed in thetutorial directories by skipping ahead to section 4.3 now.

4.2.1 USGS National Elevation Dataset

The USGS National Elevation Dataset (NED) provides continuous 1:24,000-scaled DEM data for all of the contiguous US and 1:63,360-scale DEM data forAlaska. To access this data, complete the following steps:

1. Go to http://seamless.usgs.gov , and then click on View and DownloadUnited States Data . (You could also go to GSDA site and click on

DEM , then click on DEM Data from USGS Seamless Map )

2. Choose the Find tool and type in Richfield

3. Click the OK button

4. Find the Richfield in SEVIER county, UT and click Goto

5. On the Display Tab on the right of the screen, click on the arrow nextto Hydrography

6. Select the check boxes next to National Atlas and NHD Streams and National Atlas and NHD Waterbodies as shown in Figure 4-1 . Themap should automatically update.
http://seamless.usgs.gov/http://www.emrl.byu.edu/gsdahttp://www.emrl.byu.edu/gsdahttp://seamless.usgs.gov/

8/12/2019 Tutor81 Vol i

39/67

3BDEM Basics 4-3

Figure 4-1: Display Layers

7. Use the Zoom tool to frame the area shown in Figure 4-2

8/12/2019 Tutor81 Vol i

40/67


Figure 4-2: Zoom Window

8. Under the Download section, choose the Download Area tool

9. Make the rectangle shown in Figure 4-3 . An order confirmation page

should come up

Figure 4-3: Download Selection Window

8/12/2019 Tutor81 Vol i

41/67

8/12/2019 Tutor81 Vol i

42/67




3. Locate the folder C:\Program Files\WMS81\tutorial\dembasics 4. Find and multi-select josephpeak.dem , redridge.dem ,

marysvalecanyon.dem , and trailmountain.dem

5. Choose Open

You will be taken to the Importing USGS DEMs manager. The area covered bythe DEM you have selected will be colored in a box near the center of thedialog. The boundaries of your DEM area will show up in the four edit boxes.

6. Select OK

By multi-selecting the DEMs you want, you can read in all the quads you needat the same time. WMS is able to read in an unlimited number of DEMs at atime (unless your computer runs out of memory). You can read in multipleDEMs in the standard USGS format (from the WebGIS site), the SDTS format,or Arc/Info ASCII grid format, but you cannot mix and match formats in WMS(you could export any DEM in the Arc/Info ASCII grid format in order to getthem all to a common format, though). You cannot tile multiple DEMs fromthe NED site (this should not be a problem though since the data from this siteis seamless in the first place).

4.4 Trimming DEMsWMS allows you to select the portion of the DEM you need and eliminate allof the surrounding elevation points. This can be done either with an existing

polygon or with a polygon entered interactively.

4.4.1 Trimming DEMs

1. Right-click on DEM in the Project Explorer and select Trim | Polygon

2. Choose the Enter a polygon interactively option

3. Select OK

4. Click each of the four vertices of the polygon shown in Figure 4-4 ,double-clicking on the last to close the polygon

8/12/2019 Tutor81 Vol i

43/67

3BDEM Basics 4-7

Figure 4-4: DEM Trim Area

4.5 Displaying DEMs

4.5.1 Contour Options

WMS has several options for displaying DEMs. You can change the contourdisplay options by following these steps:

1. Right-click on DEM in the Project Explorer and select ContourOptions in the pop-up menu

2. Under Contour Interval, select Number of Contours and set the edit box value to 10

3. Select OK

You can see that there are fewer contours and they are spread farther out now.

4. Right-click on DEM in the Project Explorer and select ContourOptions in the pop-up menu

5. Under Contour Method, select Color Fill

This option will color in the contours.

6. Choose the Legend button

7. Under Legend Specifications, check the Display Legend check box

8/12/2019 Tutor81 Vol i

44/67


8. Select OK twice

You can go back into the Contour options dialog and explore more of thecontour display options if you wish.

4.5.2 Point Display Step

Next you will explore the point display step option:

1. Right-click on DEM in the Project Explorer and select Display Options in the pop-up menu.

2. Change the number in the Point Display Step edit box to 4

3. Select OK

You can see that the display is not as smooth now.

4. Right-click on DEM in the Project Explorer and select Display Options in the pop-up menu.

5. Change the Point Display Step to 12

6. Select OK

7. Change the Point Display Step back to 2

Raising the point display step will allow your DEM display to refresh

noticeably faster, especially if your computer is slow. Although WMS is notdrawing every DEM point, each point that was read in is still there, sochanging the point display step does not change the accuracy.

4.5.3 Shading Options

Now you will explore the shading options:

1. Select Display | Display Options

2. Select Lighting Options

3. Toggle on Use light source

4. Click on the globe to move the light source and adjust the slide bar tochange the amount of ambient light

5. Select OK

8/12/2019 Tutor81 Vol i

45/67

3BDEM Basics 4-9

Changing the position of the light source and the ambient light alters thedisplay of the DEM. You can experiment with these options to accentuate theelevations that are most important for you to see.

4.5.4 Views

Many times it is easier to see the DEM elevations from a view other than the plan view.

1. Select Display | View | Oblique View . (Alternatively, you can alsoselect the Perspective View macro )

It is now much easier to see the changes in elevation on the DEM. If theelevation relief cannot be seen clearly, you can change the Z-magnification toaccentuate the elevation relief.

2. Select Display | View-Z Magnification

3. Enter 3 in the edit box.

4. Select OK

The image will redraw on its own. You will see the elevation relief better now.

4.6 ConclusionDEM data for the United States is found in several places on the Internet. Datais available for most areas of the US and some parts of other countries. DEMdata is very useful for delineating watersheds in WMS.

In this exercise you should have learned how to do the following:

1. Import USGS DEMs in different formats

2. Tile multiple DEMs together and edit DEM elevations

3. Set DEM display options

8/12/2019 Tutor81 Vol i

46/67

8/12/2019 Tutor81 Vol i

47/67

5 Using Triangulated Irregular Networks

CHAPTER 5

Using Triangulated Irregular Networks

Triangulated Irregular Networks (TINs) are constructed from a scattered set ofxyz vertices. They can be used for visualization, as background elevationsmaps for generating new TINs or DEMs, or to perform basin delineation anddrainage analysis. WMS has powerful tools for importing and manipulatingthis type of terrain data.

5.1 ObjectivesThe following topics will be covered in this exercise:

1. Importing survey data

2. Digitizing data

3. Triangulation

4. Automated TIN editing

5. Manual TIN editing

6. Creating a TIN using a conceptual model

7. Converting a TIN to a DEM

8. Exporting data to CAD

8/12/2019 Tutor81 Vol i

48/67


5.2 Importing Survey Data1. Close all instances of WMS

2.

Open WMS


4. Locate the Folder C:\Program Files\WMS81\tutorial\tins

5. Open surveytm.txt

6. Leave the default settings. This is a tab delimited file exported fromExcel. Select Next

7. For WMS data type choose Survey Data

8. In the File preview spreadsheet, ensure that the first, second, and thirdcolumn types are mapped to X, Y, and Z, respectively

9. Select Finish

10. Right-click on s urveytm under Terrain Data in the Project Explorerand select Display Options in the pop-up menu.

11. Toggle Unlocked Vertices on in the Tin Data tab

12. Select OK

13. Zoom in around the vertices

14. Select Edit | Current Coordinates to set your current coordinates

15. Set Horizontal System to UTM NAD 27 (US)

16. Set Horizontal Units to Meters

17. Set UTM Zone to 12 114W to 108W

18. Set Vertical Units to U.S. Survey Feet

19. Select OK

5.3 Getting a Background ImageSkip section 5.3.1 if you are not able to connect to the Internet using yourcomputer.

8/12/2019 Tutor81 Vol i

49/67

4BUsing Triangul ated Irregular Networks 5-3

5.3.1 Getting a Background Image Using the TerraServer

Using an Internet connection we will now download the topographic mapimage directly from the TerraServer and open it in WMS.

1. Select the Get Data tool

2. Drag a box around the extents of TIN vertices to define the region ofthe image

3. Toggle on the TerraServer topo option

4. Select OK to start the downloading process

5. Enter TrailMtn and click Save

6. Click Yes to accept the default file format for web files

7. Select OK to accept the suggested resolution . It may take 30 secondsto one minute to complete the downloading process.

WMS will automatically open the image after downloading it. If you were ableto successfully complete all the steps in this section you can skip section 5.3.2 .

5.3.2 Open Background Image


2. Open trailmountain.tif


5.4 Digitizing Data1. Select Display | Toolbars | Digitize to turn on the Digitize toolbar at

the bottom of the screen

2. Click on the Digitize Mode button, which is located on the Digitizetoolbar, to turn on the digitize mode

3. Enter a Z value of 6800 ft in the white box

4. Select the Add Vertices tool from the TIN toolbar (make sure youdo not select the Create Feature Point tool from the Feature Objectstoolbarit looks the same as the Add Vertices tool)

8/12/2019 Tutor81 Vol i

50/67


5. Digitize the 6800 ft contour by using the background image to addvertices

6. Click on the Digitize Mode button, which is located on the Digitizetoolbar, to turn off the digitize mode

7. Select Display | Toolbars | Digitize to turn off the Digitize toolbar atthe bottom of the screen

5.5 Converting CAD Data to a TINOften terrain data is stored/processed in a CAD program in the form ofcontours or triangles. In either case the 3D data points (x,y,z) can be convertedfrom the CAD data to TIN points and triangulated in WMS.


2. Select No when asked if you want to save changes


4. Open contours.dwg


6. Select CAD | CAD->TIN

7. Select OK

The points defining the contour lines contain x, y, and z coordinates so whenthe points are converted to TIN points and retriangulated, you are left with a3D TIN surface. You can zoom in, rotate, change the display or contouroptions in order to better visualize your TIN if you would like. You can alsoread other CAD files with 3D points and convert them to a WMS TIN.

5.6 TriangulationIn order to edit the TIN according to the steps in this exercise we will delete theexisting data and read in a TIN file before we triangulate the data.

1. In the Terrain Data folder in the Project Explorer, right-click on theCAD Layers TIN and select Delete


3. Open digitizetm.tin

8/12/2019 Tutor81 Vol i

51/67



5. Right-click on the TIN (New tin) in the Project Explorer and selectTriangles | Triangulate on the pop-up menu.

5.7 Automated TIN EditingWMS has automated methods of editing TINs so that they provide arepresentation of terrain that is useful for drainage analysis. These methodsinclude selecting thin boundary triangles, transforming data, and eliminatingflat triangles and pits. Thin boundary triangles, which result from triangulatingthe data, do not necessarily represent the terrain and are automatically deletedat the end of the triangulation process. Data transformations are especiallyuseful for converting elevations between feet and meters. Flat triangles need to

be eliminated for drainage analysis. Inaccurate basin delineation can result

from pits because water flows into the pits rather than to the actual outlet.

5.7.1 Transformations

Run the cursor over the TIN and notice that the z values in the help strip at the bottom of the WMS window are in feet.

1. Select TIN | Vertices | Transform

2. Enter 0.3048 for the Z Scale value to scale the elevations in feet tometers

3. Toggle on the Frame image after transformation option

4. Select OK

Run the cursor over the TIN and notice that the z values in the help strip arenow in meters.

5.7.2 Flat Triangles

1. Right-click on the TIN (New tin) in the Project Explorer and select Display Options on the pop-up menu.

2. Select TIN Data and toggle Flat Triangles on

3. Select OK

4. Right-click on the TIN (New tin) in the Project Explorer and selectTriangles | Remove Flat Triangles on the pop-up menu.

8/12/2019 Tutor81 Vol i

52/67


5.7.3 Pits

1. Right-click on the TIN (New tin) in the Project Explorer and select Display Options in the pop-up menu.

2. Toggle Pits on in the TIN Data tab.

3. Select OK

4. Right-click on the TIN (New tin) in the Project Explorer and select Vertices | Smooth Pits on the pop-up menu.

Some pits may remain even after using this command.

5.8 Creating a TIN Using a Conceptual ModelA conceptual model built using feature object data can be used to create a TIN.This is important because an arbitrary triangulation of scattered data pointsmay not produce a TIN that is suitable for drainage analysis (e.g. triangle edgesenforced along streams and ridges). If you have a set of scattered data points itmay be a good idea to triangulate them and then treat them as a backgroundelevation map for creating a new TIN using a conceptual model.

5.8.1 Open Files




4. (If you successfully completed 5.3.1 ) open TrailMtn.tstopo.web.jpgotherwise open trailmountain.tif


6. Open digitizetm.tin

7. Zoom in around the xyz data

5.8.2 Triangulation


2. Toggle Flat Triangles and Pits off

8/12/2019 Tutor81 Vol i

53/67


3. Select OK

4. Right-click on the TIN (New tin) in the Project Explorer and select Triangles | Triangulate on the pop-up menu.

5.8.3 Creating Feature Arcs for a Conceptual Model


2. On the TIN tab, toggle Unlocked Vertices and Triangles off

3. Select OK

4. Click on the Drainage coverage in the Project Explorer to make itactive

5. Select the Create Feature Arc tool


7. Make sure the current feature arc type is set to Generic and select OK

8. Use the Create Feature Arc tool to create an arc that begins andends at the outlet and follows along the inside edge of the TIN

boundary as shown in Figure 5-1

Figure 5-1: Creating an arc along the TIN boundary

8/12/2019 Tutor81 Vol i

54/67


9. Use the Create Feature Arc tool to create an arc starting at theoutlet that follows the stream on the background image as shown inFigure 5-1 . Make sure you create the arc from downstream toupstream.

10. Use the Select Feature Arc tool to select the arc along the stream


12. Choose a Feature Arc Type of Stream

13. Select OK

14. Use the Select Feature Arc tool to select the arc along the TIN boundary

15. Right-click on the Drainage coverage and select Build Polygon

5.8.4 Redistribute Vertices

The size of the triangles created during triangulation depends on the spacing between vertices.

1. Use Edit | Select All to select all feature arcs

2. Select Feature Objects | Redistribute

3. Enter a Spacing of 60

4. Select OK

5.8.5 Create TIN


2. On the TIN tab toggle Triangles on

3. Select OK

4. In the Map module, Select Feature Objects | Create TIN

5. Select No

6. Toggle the Display triangulation process option on

7. Select OK

8/12/2019 Tutor81 Vol i

55/67


The existing TIN is replaced with a new TIN that was created using the featurearcs that are part of the conceptual model.

5.8.6

Flat Triangles and Pits1. Right-click on the TIN (New tin) in the Project Explorer and select

Display Options on the pop-up menu.

2. Toggle Flat Triangles and Pits on

3. Select OK

4. Right-click on the TIN (New tin) in the Project Explorer and select Triangles | Remove Flat Triangles on the pop-up menu.

5. Right-click on the TIN (New tin) in the Project Explorer and select Vertices | Smooth Pits on the pop-up menu.

5.9 Convert to DEM1. Right-click on the TIN (New tin) in the Project Explorer and select

Convert | TIN->DEM on the pop-up menu.

2. Enter a cell width and cell height of 10

3. Select OK

4. Select Yes

5. In the Map Data folder in the Project Explorer hide the display ofTrailMtn.tstopo.web by toggling the visibility check box off

6. Switch to the Drainage module


8. Select DEM | Compute TOPAZ Flow Data

9. Select OK

10. Select OK

11. Select Close once TOPAZ finishes running (you may have to wait afew seconds to a minute or so)


8/12/2019 Tutor81 Vol i

56/67


13. Select DEM Data and change the Minimum Accumulation For Displayto 0.005 mi 2

14. Select OK

15. Select the Create Outlet Point tool

16. Create an outlet as shown in Figure 5-2

Figure 5-2: DEM outlet

17. Select DEM | Delineate Basins Wizard

18. Select OK

19. Select OK

20. A drainage boundary is created using the DEM data. The basin data forthis drainage basin is computed

5.10 Exporting Data to CAD

Data that is visible on the screen can be converted to CAD data and then savedfor use in CAD programs.


2. Select CAD | Data -> CAD

In order to view only the newly created CAD data we will hide all other data.

8/12/2019 Tutor81 Vol i

57/67


3. Hide the Map Data Coverages folder in the Project Explorer bytoggling its visibility check box off

4. Hide the Terrain Data folder in the Project Explorer


6. Select DEM Data and toggle Color Fill Drainage Basins and Fill Basin Boundary Only off

7. Select OK

8. Select CAD | Display Options

9. In the Visibility column toggle Drainage_arcs off

10. Select Apply . Notice the CAD data that disappears when selecting this button

11. Select Cancel

12. Select File | Save As

13. For Save as type choose the DWG files (*.dwg) filter

14. Select Save

8/12/2019 Tutor81 Vol i

58/67

8/12/2019 Tutor81 Vol i

59/67

6 Advanced Feature Objects

CHAPTER 6

Advanced Feature Objects

In a previous exercise (chapter 3) you learned how feature points, lines, and polygons are created and organized into coverages. In this exercise you willcontinue to learn about the creation and editing of feature objects, with a focuson creating drainage coverages, the primary coverage used in WMS to developwatershed models.

6.1 ObjectivesIn this exercise you will learn the how to create and import feature objects andmanage different coverages. This includes the following:

1. Using feature object drainage coverages for watershed delineation

2. Advanced feature object editing functions

3. Assigning appropriate feature object attributes

4. Importing and editing feature objects from CAD data

6.2 Defining a Watershed with Feature ObjectsBy using a combination of stream arcs, outlet nodes, and basin polygons, youcan develop an entire watershed without the use of a digital terrain model. Thewatershed can be to scale or a schematic. Of course, if it were not to scale,

polygon areas and stream lengths would not be valid for your hydrologicmodel.

8/12/2019 Tutor81 Vol i

60/67


In this section of the exercise you will create the Aspen Grove watershed froman image of a scanned paper map with clearly marked streams and basin

boundaries.


2. Open WMS



5. Locate the folder C:\Program Files\WMS81\tutorial\featureadv

6. Open aspentrc.img

You should see a portion of a USGS quad map with basin boundaries outlinedin red and the stream network in black.

6.2.1 Creating Basin Boundaries

We will begin by creating the basin boundaries, but it does not matter whetherthe basins or streams are created first.



3. Make sure that the arc type is Generic and Select OK

4. Beginning at the outlet point (lower right) trace out the entirewatershed boundary. You do not need to follow every detail; take asmuch time as you want.

5. Now create each of the three sub-basin boundary arcs on the interior ofthe watershed. Begin by clicking on a point near the junction in thecenter of the watershed and ending by clicking near the intersection ofthe arc previously created for the exterior boundary.

6.2.2 Creating the Stream NetworkThe stream network is created in much the same way the basin boundarieswere. The only thing to note is that in the upper basin the basin boundarycomes very close to the stream. You will need to zoom in on this region inorder to avoid conflicts with the snapping tolerance.


8/12/2019 Tutor81 Vol i

61/67

5BAdvanc ed Feature Objects 6-3

2. Choose the Stream feature arc type

3. Select OK

4. Create the main channel from the outlet of the watershed to the outlet point for the two upper basins. Begin by clicking near enough to the boundary arc at the outlet so that it snaps to it and end by clicking onthe basin junction point.

5. Create the two branches of the lower basin by clicking on a point nearthe stream arc just created and double-clicking at the most upstream

point of the branches in the image.

NOTE: As you create new vertices on stream arcs you should always do sofrom downstream to upstream.

6. Choose the Zoom tool

7. Zoom in on the region shown in Figure 6-1

Figure 6-1: Junction of Main Channel in Aspen Grove Watershed.


9. Create the initial portion of each stream by clicking on the junction point (intersection of red boundary lines in the image) and going as farupstream as is possible on the zoomed image. End by double-clicking.

You needed to zoom in order to avoid conflicts with the auto-snapping feature.However, if you click too close to an existing arc, you will get a message thatthe stream is illegal and you will need to try again.

You can end the stream at one location and then continue defining afterzooming out by beginning at the point where you left off.

8/12/2019 Tutor81 Vol i

62/67


10. Select Display | View | Previous View

11. Finish defining each branch. Begin the branch by clicking near the point you left off with and ending by double-clicking at the terminal

point of the stream.

In order to define separate basins at the junction point you will need to convertthe node at the junction to an outlet node.


13. Select the junction point in the center of the watershed correspondingto the intersection of the streams and the sub-basin boundary arcs thatyou just created.


15. Set the attribute to Drainage outlet

16. Select OK

6.2.3 Building Polygons

At this point the watershed boundaries are only arcs. In order for them to become polygons you must create the polygon topology.

1. Choose the Select Feature Line Branch tool

2. Select Edit | Select All

3. While holding down the SHIFT key, select the southern-most streamarc. This deselects the stream arcs and leaves the remainder selectedfor use in polygon generation.

4. Right-click on the Drainage coverage and select Build Polygon

5. Choose the Select Feature Polygon tool and double click on each basin polygon and change the type to Drainage Boundary

6.2.4 Updating Geometric Parameters1. Right-click on the Drainage coverage in the Project Explorer and

select Display Options on the pop-up menu

2. Select Map Data and turn on the Color fill polygons option

3. Select OK

8/12/2019 Tutor81 Vol i

63/67


In order to transfer the basin area and stream lengths and to compute them inappropriate units for hydrologic modeling, you need to compute the basin data.This will make it possible to use the polygon area in any of the hydrologicmodeling interfaces.

4. Right-click on the Drainage coverage in the Project Explorer andselect Compute Basin Data . This command computes areas,

perimeters, and centroids for each of the sub-basins and assigns thesevalues to the hydrologic modeling tree

5. In the Units dialog, select the Current Coordinates button

6. Make sure the Horizontal and Vertical units are Meters (the base unitswere UTM meters)

7. Select OK

8. Set the Basin Areas units to Square miles

9. Set the Distances units to Feet

10. Select OK to compute the sub-basin data

6.3 More Basin Delineation Now that you have the basics of digitizing a watershed from a topographic mapand developing the correct topology for the watershed, you can try it again

without the burned in lines on the image or the step by step outline.

6.3.1 Single Basin Delineation

For the first part of this exercise you will delineate the entire watershed as asingle basin.




4. Open uppertrailmt.jpg

You should have a portion of a scanned topographic map that has already beengeoreferenced. You should now delineate the watershed as a single basin,including the streams as indicated by the blue lines. Your final watershedshould look similar to Figure 6-2 with an area of about 1.5 square miles. Step

by step procedures will not be given this time, but you can refer back to

8/12/2019 Tutor81 Vol i

64/67


previous sections for help and to the Figure 6-2 . The following are a list ofthings you will want to remember:

5. Start by digitizing the streams and remember to make sure the featurearc attribute type is set to stream and that you digitized fromdownstream to upstream.

6. Digitize the boundary with arcs that are of type generic

7. Build polygons once you have created the arcs that form the boundary

8. Compute the basin data when you are done and make sure that themodel units are meters

Figure 6-2 Delineated Upper Trail Mountain Watershed as a single basin.

6.3.2 Adding Sub-basins

Once you have successfully digitized the watershed as a single basin, add twointerior outlets as indicated in Figure 6-3 and digitize the sub-basin boundaries.

Note in Figure 6-3 that the sub basin on the left side is defined by converting

8/12/2019 Tutor81 Vol i

65/67


the vertex just below the junction of the stream to an outlet, thus treating that branch as a single basin, whereas the outlet for the right sub basins is placed onthe node that defines the junction of the streams, thus creating a separate basinfor each upstream branch. Some important considerations are:

1. For the left side basin you will need to convert a vertex to a node

2. Be sure to change the attribute of the node defining the outlets to typeoutlet

3. Digitize the sub-basin boundaries with generic arcs and rebuild the basin polygons when you are done

4. Compute basin data

Figure 6-3 Delineated Upper Trail Mountain Watershed with sub basins.

Outlet at junction

Outlet below junction

8/12/2019 Tutor81 Vol i

66/67


6.4 Feature Objects from CAD DataYou may have CAD data available (or shape files which would follow a similar

process). DWG and DXF data can be automatically converted to feature

objects in WMS.



3. Ensure that you are in the Map module


5. Open af.dwg

6.

Select CAD | CAD -> Feature Objects

The dialog that opens shows a check mark for each layer that will be convertedto feature objects. We will convert all layers and accept the default coveragetype (which should be Drainage) and name (which should be CAD layers).

7. Select OK

8. Select OK to accept the coverage type and name

9. Select CAD | Display Options

10. Toggle off the check box at the top labeled Display CAD data

11. Select OK

Because these lines were created in AutoCAD, we cannot be sure that thestreams were created using the WMS conventions for direction (and in mostcases they will not be). In order to fix any such problems you can use theReorder Streams command. By selecting the most downstream node in astream network and invoking the Reorder Streams command, you tell WMS toensure that all arcs are ordered downstream to upstream from the selected

point.


13. Right-click on the left-most node in the interior of the basin (the left-most node on the portion that forms a network inside of the arcsforming a boundary) and select Reorder Streams on the pop-up menu.

14. Choose the Select Feature Line Branch tool

8/12/2019 Tutor81 Vol i

67/67


15. Select the arc attached to the left-most node (the node that was justused to reorder streams)


17. Select the Stream type and select OK

Each stream now flows the proper direction, toward the one drainage outlet atthe left of the stream network. This outlet needs to be snapped to the basin

boundary.


19. Right-click on the drainage outlet and select Clean on the pop-upmenu.

20. Make sure Snap selected nodes is checked

21. Select OK

22. Choose the node on the basin boundary closest to the drainage outlet

23. Right-click on the CAD layers coverage and select Build Polygon

24. Select OK

This set of streams and basins is now properly ordered and connected and isready to be used for hydrologic analysis.

6.5 ConclusionIn this exercise you should have learned how to do the following:

1. Use feature object drainage coverages for watershed delineation

2. Assign appropriate feature object attributes

tutor81 vol i

Documents