Bringing Data Points Into Arcview3

Bringing point data into ArcView 3x Step 1: Get the data into a format with at least these three minimum fields: Some sort of unique water source / hydrant ID number 1

X – Coordinate (Decimal Degrees)

Y – Coordinate (Decimal Degrees)

-70.259583

44.239150

Hints: Don’t forget to have the Y coordinate as a negative number… or you'll end up in Kazakhstan! Also, don't forget to format the cells containing the X and Y coordinates as numbers with an appropriate number of decimal places – before saving the file as a DBase (dbf). If you forget this step when converting the data into a .dbf, it will truncate most if not all of the decimal places, so all of your points will end up on top of each other. Additional fields might include Description of water source, Directions to the source, etc. Step 2: Save the file as a D-Base in a location that is accessible to ArcView Step 3: Open up ArcView 3x and start a new project. Then click on the "Tables" icon and click on the "Add" button – navigate to your D-base file, select it, then click the "Ok" button. Step 4: Click on the "View" icon, then go to the "View" menu and select "Add Event Theme" Step 5: Locate your D-Base file and select it – indicate which fields contain your X and Y data (this is done "automatically" if you name your fields X, Y). Step 6: Select the event theme (usually has the same name as the original D-Base file) then go the "Theme" menu and select the "Convert to shapefile" option to turn the event theme into a bona fide Shapefile. Now you will need to add projection information to your new shapefile. Go to the Shapefile Projection Utility – which is usually located at the same level as the ArcView icon from the Windows "Start" button. Step 7: Once you are in the Projection Utility click on the "Browse" button and navigate to your new shapefile, select it and then click on the "Open" button. Now click on the "Next" button. Step 8: If the points we collected with a GPS, select the "Geographic Radio Button" and then select "GCS_WGS_1984 [4326] option from the first drop down menu. Make sure that the "Units" are "Degree [9102] in the second drop down menu. Note: if some other known coordinate / projection system was used when collecting the points by GPS, then be sure to change the above options to reflect whatever system was

in use by the GPS when the coordinates were being collected. If this information is unknown, my first choice is to use the WGS84 system because that is the geoid that the GPS system uses by default. Step 9: Click "Next" then "Yes" to save the projection information with your existing Shapefile. Now select the "Projected Radio Button" and then select "NAD_1983_UTM_Zone_19N [26919]" option from the first drop down menu. Make sure that the "Units" are "Meter [9001] in the second drop down menu. Now click the "Next" button then the "No" button to save the new projection information to your shapefile. You will want to "Browse" to the folder where you want to save the reprojected shapefile, give it a new name, then click the "Next", "Finish" and "Ok" buttons to complete this process. Note: The above process will save the shapefile with the same NAD83 / UTM Zone 19N that most other MEDEP data follows. Step 10: Now bring the re-projected shapefile into ArcView 3x and you should see your points on the screen – check them against a roads layer or another set of base data to ensure that they are at least in the correct town! If these data points do not line up with the other datasets – most likely some mistake or incorrect assumption (i.e. the data was collected in WGS1984 datum) was made during the projection and re-projection process… You will have to do some homework and start over at Step 7 again. Hint the quickest way to check this is to compare the original shapefile with the re-projected one – if they do not line up with each other, then the reprojection process should definitely be checked again.