3. catchment delineation workflow - unimasr€¦ · m. elkordy catchment delineation workflow dec...

Catchment Delineation WorkflowM. Elkordy Catchment Delineation Workflow

Dec 2012Slide 1

Catchment Delineation Workflow


Dec 2012Slide 2

Catchment Delineation Workflow• Given is a GPS point (Lat./Long.) for an outlet

location.• The outlet could be a proposed Dam site, a

storm water drainage culvert on a rural highway, or any other feature that is believed to be attacked by a stream.

• It is required to define the catchment that attacks the outlet point: Compute catchment parameters (area, slope, length,…etc)


Dec 2012Slide 3

Catchment Delineation Workflow• Steps:

1. Preparation• Preparing the DEM, Satellite images,.. etc

2. Delineating the Catchment• Initial Delineation inside WMS

3. Streams Verification• Correcting the streams as needed

4. Visualizing the Catchment


Dec 2012Slide 4

Catchment Delineation Workflow• Software Needed:

– Global Mapper– WMS– Google Satellite Maps Downloader– Google Earth

Latitude 21.498059° N

Longitude 41.601192° E


Dec 2012Slide 5

Step1: Preparation


Dec 2012Slide 6

Preparation• Software Needed:

– Global Mapper– WMS– Google Satellite Maps Downloader– Google Earth




Dec 2012Slide 7

Preparation- Open Google Earth. (Make sure that you use the latest version)


Dec 2012Slide 8

Preparation- Now add a Placemark. Place it Anywhere.


Dec 2012Slide 9

Preparation- Adjust the

name of the Placemark to be “GPS Point”

- Adjust the Latitude and longitude to be the same of the outlet point

- Press Enter. (The placemarklocation will change automatically to be near Makkah)




Dec 2012Slide 10

Preparation- Now to the GPS

point and inspect nearby streams from the picture.

- Images in Google earth are usually high resolution images that allows for close lookups.

- The area looks to be flat at the outlet

Stream visually identified from sporadic vegetation


Dec 2012Slide 11

Preparation- It is required to

prepare the DEM and satellite images needed to cover the catchment boundary feeding this stream.

- To get a preliminary estimate of the stream boundary, free GIS data shall be used

Flow direction identified visually from Satellite Image and Elevation in Google Earth


Dec 2012Slide 12

Preparation- Go to the

Geocommunitywebsite

- Press “S” from the Data –Country Index

- Select Saudi Arabia from the country list

http://data.geocomm.com/catalog/


Dec 2012Slide 13

Preparation- Select Nation

Wide Data

- Select the “Hydrography –1M – E00 Format.

http

://da

ta.g

eoco

mm

.com

/cat

alog

/


Dec 2012Slide 14

Preparation- Select to

download the “Drainage –Network” E00 file. Data is free of charge.

- You will need to have a geo-community account in order to download the data.

- The downloaded file is located on the CD and named “KSA-DNNET.E00”


Dec 2012Slide 15

Preparation- Open “Global

Mapper” Program

- Drag and Drop the “KSA Dnnet.e00” file that we have just downloaded into the main window.

- Press OK on the error message that appears


Dec 2012Slide 16

Preparation- Global mapper

needs to know the projection of the incoming data to align it correctly

- Select the “Geographic (Latitude/Longitude) as the Projection

- Select the WGS84 as the Datum

- Press OK


Dec 2012Slide 17

Preparation- All drainage

network of Saudi Arabia shall appear now on the screen

- The delineated streams are of low resolution however they give a good indication of the catchment extents


Dec 2012Slide 18

Preparation- Go to File >

Export Vector Format

- Select to export vector data as “KML / KMZ”. This is to view the data on Google Earth


Dec 2012Slide 19

Preparation- Leave all the

export options the same and press OK.

- Name the file “KSA Drainage Network”


Dec 2012Slide 20

Preparation- Double click the

“KSA Drainage Network” file. It shall open up in Google earth and the streams shall appear on the image

- Now zoom back to the GPS point and inspect the stream network

- Try to define approximately the extent of the catchment


Dec 2012Slide 21

Preparation- Add a Polygon in

Google earth covering an area more than the catchment extent and name it “DEM Boundary”

- Use the controls in the Upper Right corner to pan and zoom while drawing.


Dec 2012Slide 22

Preparation- The polygon may

appear as in the figure to the left.


Dec 2012Slide 23

Preparation- Right click on the

“DEM Boundary” polygon feature that appears in the places tree and select “Save Place As..”

- Save the polygon as “DEM Boundary.kmz” so we can use it later in Global Mapper


Dec 2012Slide 24

Preparation- Go to

http://srtm.csi.cgiar.org/ in order to download the latest SRTM 3’’ DEM tile for the catchment boundary

- There are many ways to download the SRTM data.

- Scroll down the page and download the SRTM KML file “SRTM41.kmz”

http://srtm.csi.cgiar.org/


Dec 2012Slide 25

Preparation- Double click on

the SRTM41.kmz file. It shall open up in Google earth

- For viewing purposes, uncheck the box near the “KSA Drainage Network” and make sure that all the SRTM4.1 boxes are checked on


Dec 2012Slide 26

Preparation- Now zoom out

- You will find a grid lines drawn on the earth showing the boundary of each SRTM tile.

- The file name covering the catchment boundary is “srtm_45_08”

- Click on “Data for” srtm_45_08” to see download options


Dec 2012Slide 27

Preparation- A popup window

shall appear.

- Scroll down to the Download section

- Select to download “HTTP: Download the DATA tile in zipped GEOTIFF format (from London server)”

- Save the file on your computer “srtm45_08.zip”


Dec 2012Slide 28

Preparation- Extract data from

“srtm45_08.zip” on your computer

- Drag and drop the srtm_45_08.tif file into global mapper.

- Elevation data shall appear now in global mapper as a color relief box and an elevation scale shall appear on the left


Dec 2012Slide 29

Preparation- No go to Tools >

Control Center and uncheck the box beside the “KSA dnnet.e00” file to close its layer.

- Press Close


Dec 2012Slide 30

Preparation- Now Drag and

Drop the “DEM Boundary.kmz” that we have previously created.

- The boundary shall appear as in the figure to the left.


Dec 2012Slide 31

Preparation- Now press on the

“Feature Info Tool”

- Press OK to the Tip that will appear

- Select anywhere inside the DEM boundary polygon. It should get highlighted in white

- Close the info screen that shall appear. The boundary will remain selected


Dec 2012Slide 32


Export Elevation Grid Format


Dec 2012Slide 33

Preparation- Select “DEM” for

the Export Format. This is supported by WMS

- Press OK to the Tips that will appear

- On the DEM Export Options, go to Export Bounds and select “Crop to the Selected area feature” and press OK.

- Name the saved file “Cropped DEM.dem”


Dec 2012Slide 34

Preparation- Open Google

Satellites Map Downloader

- Adjust the settings and download bounds as in the image to the left.

- image bounds can be obtained approximately from Google Earth

- Zoom 15 will result in about 4m resolution image

- Press Download


Dec 2012Slide 35

Preparation- When Download is

finished, go to Tools > Combine Images

- Select the project file “SaudiDAM.gmidto combine the images into one big bitmap file “Sat Image.bmp”.

- Press Combine

- The final image will be located inside the “C:/Downloads/ SaudiDAM/” folder


Dec 2012Slide 36

Preparation- Go to

“C:/Downloads/ SaudiDAM/” folder and Drag / Drop the “SAT Image.bmp” file into Global mapper.

- Press OK to the message that will appear

- Select “Geographic” as the projection and “WGS84” as the Datum

- Press OK


Dec 2012Slide 37

Preparation- The image will

appear to be placed correctly in the drawing. However, it is not orthorectifiedcorrectly.


Dec 2012Slide 38

Preparation- Go to Tools >

Control Center and right click on the “SAT Image.bmp” file.

- Select RECTIFY

- Press OK to the Tip that will appear.


Dec 2012Slide 39

Preparation- Press the “Select

Projection” button in the Ground Control Point (GCP) Projection section


Dec 2012Slide 40

Preparation- Select the

“Mercator” as the projection and “WGS84” as the Datum

- Press OK


Dec 2012Slide 41

Preparation- Press “YES” to

Reproject the GCPs to the new projection. This is very important.

- Press OK to the RECTIFY dialogue window.

- Now the image is correctly placed and projected.

- Now close all layers except the SAT Image.bmp layer


Dec 2012Slide 42

Preparation- Go to Tools >

Configure.

- In the Projection tab adjust the projection of the file to be UTM zone 37 North and the datum to be WGS84.

- Press OK

- This will project all the data in the file into the UTM zone 37 projection


Dec 2012Slide 43


Export Raster/Image Format


Dec 2012Slide 44


Export Raster/Image Format

- Press OK to the Tips window

- Leave the JPG Export options unchanged and press OK

- Save the file as “SAT Image.jpg”

- A .prj and .jgw files will be saved automatically with georeferenceinformation


Dec 2012Slide 45

Step 2: Working inside WMS


Dec 2012Slide 46

Working inside WMS- Open WMS

version 7.1


Dec 2012Slide 47

Working inside WMS- Drag and Drop the

“Cropped DEM.dem” file into the WMS main window

- Uncheck the “Smooth DEM on Import”

- Press OK to start importing elevation data


Dec 2012Slide 48

Working inside WMS- Remember that

the original M data was in Geographic projection (Lat/Long degrees).

- WMS requires to project the data into a plainimetriccoordinate system for delineation.

- Press YES


Dec 2012Slide 49

Working inside WMS- Now edit the

Project Coordinate system first to be Geographic, WGS84, North and East.

- Then edit the project coordinate system to be UTM Zone 37, WGS84.

- Press OK


Dec 2012Slide 50

Working inside WMS- Now contour lines

are displayed in the main window.

- The file is projected in UTM zone 37 now

- Coordinates X,Y, and Z of any point is displayed in the lower left bar.


Dec 2012Slide 51

Working inside WMS- Go to the drainage

Module

- Go to DEM > Compute TOPAZ Flow Data to calculate the flow accumulations


Dec 2012Slide 52

Working inside WMS- Leave all options

the same and press OK


Dec 2012Slide 53

Working inside WMS- Adjust the Basin

Areas to “Square Kilometers” and the Distances to “Meters”

- Press OK


Dec 2012Slide 54

Working inside WMS- When Done,

Press “Close” to the Model wrapper window


Dec 2012Slide 55

Working inside WMS- Now streams

appear on the plan.

- The default threshold value for drawing streams is 1.0 square kilometers. This value can be changed from the Display options.


Dec 2012Slide 56

Working inside WMS- Now we need to

place the GPS point in side WMS.

- Given coordinates of the PS point in geographic Lat/long while WMS file now is in UTM Projection

- First open Global Mapper to find the GPS point coordinates in UTM zone 37 coordinates.

- Go to Tools > Coordinate Convertor


Dec 2012Slide 57

Working inside WMS- Edit the Input

Coordinates and the Output Coordinates as in the figure to the left.

- Write the long/latof the outlet point

- Press Convert to

- Values written in the X and Y fields are the new coordinates to be used in WMS


Dec 2012Slide 58

Working inside WMS- Open the Terrain

Module in WMS

- Select the “Create Feature Point” button


Dec 2012Slide 59

Working inside WMS- Place the point

anywhere inside the contour lines

- Copy and paste the X and Y coordinates from Global Mapper to the X and Y Fields inside WMS and press enter

- The feature point location will be changed automatically


Dec 2012Slide 60

Working inside WMS- Go to the

Drainage Module again

- Zoom in to the Feature Point Location

- Create an outlet point on the stream (blue) nearest the feature point location

Feature Point

Outlet Point


Dec 2012Slide 61

Working inside WMS- Go to DEM >

Delineate Basins Wizard

- Check the Display feature arc creation option

- Leave the threshold value to 1.0 km2 and press OK


Dec 2012Slide 62

Working inside WMS- Press OK to

calculate the Basin Data


Dec 2012Slide 63

Working inside WMS- Catchment

Delineation is Done

- Save the WMS file in a new folder


Dec 2012Slide 64

Working inside WMS- Select the “Select

drainage unit or basin” button.

- Double click anywhere inside the catchment boundary

- Press on “Unit Hydrograph Method” button


Dec 2012Slide 65

Working inside WMS- Press on “Basin

Geometrical Attributes”

- The calculated Basin Data will appear.

- When done press Cancel to return to the main WMS window


Dec 2012Slide 66

Step 3: Verifying the Catchment


Dec 2012Slide 67

Verifying the Catchment- Drag and Drop the

“SAT Image.jpg” file into the WMS main window

- The image shall appear in its place overlaid over the catchment and streams

- Carefully verify the streams and catchment boundary delineated by WMS with the satellite image.


Dec 2012Slide 68

Verifying the Catchment- For Some

reasons, it is decided to include stream A in the figure to the left inside the catchment

- The could be because the elevation difference between the stream ad the catchment boundary is small such that water is expected to overtop the boundary

Stream A

Outlet

Catchment Boundary

Flat Area


Dec 2012Slide 69

Verifying the Catchment- Go to the Terrain

Module

- Press on the “Select DEM Points” button to use this tool

- We are going to manually edit the DEM cells


Dec 2012Slide 70

Verifying the Catchment- We need to

manually reverse the flow direction of the shown 4 DEM cells to include the additional stream inside the catchment.

Cell 3

Cell 2

Cell 1

Cell 4


Dec 2012Slide 71

Verifying the Catchment- First Double click

on Cell 3.

- Adjust the flow direction to be downwards

- Press OK

Before

After


Dec 2012Slide 72

Verifying the Catchment- Uncheck the three

boxes and press OK

- We shall perform these calculations when all edits are done


Dec 2012Slide 73

Verifying the Catchment- Repeat the same

with Cell 2 then cell 1

Before

After


Dec 2012Slide 74

Verifying the Catchment- Repeat the same

with Cell 4

Before

After


Dec 2012Slide 75

Verifying the Catchment- This time check all

the boxes to recalculate everything


Dec 2012Slide 76

Verifying the Catchment- Stream Direction

is modified

- However, the catchment boundary is not

- Go to DEM > Delineate basin wizard and repeat the delineation process again. Press ok to the warning message that shall appear. Delineation will be repeated using the same outlet point


Dec 2012Slide 77

Verifying the Catchment- Stream Direction

is modified




Dec 2012Slide 78

- Stream Direction is modified



Verifying the Catchment


Dec 2012Slide 79

Step 4: Visualizing the Catchment


Dec 2012Slide 80

Visualizing the catchment- Go to the Map

Module

- Go to CAD > Data -> CAD


Dec 2012Slide 81

Visualizing the catchment- Go to the Map

Module

- Go to CAD > Data -> CAD

- Save the file.

- An AutoCAD drawing shall appear in the WMS file folder with the same name


Dec 2012Slide 82

Visualizing the catchment- Drag and drop the

AutoCAD drawing file into Global Mapper

- Press OK

- Define the projection of the CAD drawing as UTM Z37 and WGS84 as datum

- Press OK


Dec 2012Slide 83

Visualizing the catchment- The delineated

Catchment will appear in place in Global Mapper


Dec 2012Slide 84

Visualizing the catchment- Go to Tools >

Control Center

- Close all layers except the ACAD Drawing


Dec 2012Slide 85

Visualizing the catchment- Go to File >

Export Vector Format

- Select KML/KMZ for export format

- Leave all export options the same

- Save the file on your computer


Dec 2012Slide 86

Visualizing the catchment- Open the KMZ file

in Google Earth


Dec 2012Slide 87

Additional Exercise

Latitude 22° 14’ 17’’ N

Longitude 39° 51’ 04’’ E

3. catchment delineation workflow - unimasr€¦ · m. elkordy catchment delineation workflow dec...

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