WEEK 9: GIS 4043 VECTOR ANALYSIS II

PROCESS SUMMARY DESCRIPTION

NOTE:  A little more detailed, simply because it helps highlight every single step taken and makes it easier to reference areas that may have been complex when first done.

Open ArcMap and minimize the window>download this week’s file (NOTE: Vector II.zip)>unzip>Open ArcCatalog 10 and minimize the window then drag “Roads.shp” to Blank ArcMap Template>Maximize window to be able to see ArcTool Box>ArcToolbox: >a. Analysis Tools>b.  Proximity>c. Buffer(OBSERVE: Buffer window comes up)>input options as shown: >a. Input Features = Roads>b.  Output Feature Class = S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Roads_Buffer.shp (NOTE:  Record the output under this weeks file as “Roads_Buffer”)>c.  Distance (value or Field) = check the Linear Unit box and enter distance as 300 meters>d.  Side Type = FULL>e.  End Type=ROUND>f.  Dissolve Type = ALL>OK (OBSERVE:  A message comes up at the bottom right of the screen saying “buffer”.  When done a green checkmark is shown at the same location at the bottom of the screen and a new layer [Roads_Buffer] appears on your map.  Also a buffer feature is now around the initial roads on the map.)>Turn off the Roads_Buffer layer under TOC>Save File (Vector Analysis II_AK.mxd under this week’s folder) and move on to step 2: CREATING A VARIABLE DISTANCE BUFFER: >To ArcCatalog Minimized Window: drag into your ArcMap the shapefile “Water.shp”>Save and Close File in ArcMap in order to be able to update it’s attribute table in ArcCatalog10 (NOTE:  Will be unable to change attribute table when file is open in ArcMap10, or any file for that matter is open in ArcMap10.  Completely exit from all instances of ArcMap10>ArcCatalog10>under contents tab, right click on file water.shp>properties>scroll down to empty field and click on the row to highlight Field Name and Data Type (NOTE:  Data Type will be highlighted in Black while the first field, “Field Name” will be highlighted in white)>Start typing (NOTE:  Will begin to type in the first box = Field Name Box>type, “BUFFDIST”>Tab to Data Type Column (NOTE: Drop down menu option pops up) – select “short integer”>(NOTE:  To delete a field name and data type if you make a mistake or do not want it, simply highlight the row and hit delete on keyboard)>Reopen file in ArcMap 10>Open  Attribute table (OBSERVE: the new attribute is automatically added to the properties for the water layer.  Also notice that under Type have both lakes and rivers (13 lakes and 1 river)>TO ASSIGN DIFFERENT VALUES TO LAKES AND RIVERS:>Under attributes table – click select by attributes and input the following information: >a.  Method = Create a new selection (NOTE:  You can also select from current selection but before doing this you will have preselected  ALL rows in the attribute table – select first row>hold shift key down and scroll to last row and click to select – highlights all columns)> b.  Double click on type to drop it in the “select from water where:” box>c.  click on the “=” sign>d. Click on “Get Unique Values” button>e.  Double click on ‘Lake’ to drop it in the “select from water where:” box>f.  verify (NOTE:  A message comes up “the expression was successfully verified”>OK>Apply(NOTE:  All 13 lakes are selected – the number is displayed under the (13 out of 14 selected)>scroll to the buffdist column and right click on column heading>select “Field Calculator Function (OBSERVE:  A Field Calculator window pops up)>Enter the following information in the Field Calculator window: >a.  Parser = VB Script>b.  Fields = Leave as is>c.  Show Codeblock = leave as is>d.  Type = see that Number is checked>e.  Functions = Leave as is>buffdist = box = type in 150>OK(OBSERVE:  Get a Processing window with the message “calculating records”.  Once done should see all the 13 lakes assigned the value 150 under the buffdist column>Repeat for the river (NOTE:  To deselect under the attribute table, click on the far top left box at the start of the column headings)>(NOTE: when the select by attributes window comes up be sure to delete the previous expression from the “select from water where:” box and select river instead of lakes this time. Should see that one selection is made>Assign the value 500 as done above with 150>Now that both have been assigned values, deselect attributes table as shown above (NOTE:  Be sure to do this so that the buffering is applied to all and not just where you left selected)>Close  the Attributes table and open ArcTool Box to the Buffer window as indicated above>Under the Buffer window, enter the shown information:>a.  Input Features = Water> b.  Output Feature Class = S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Water_Buffer.shp (NOTE:  Record the output under this weeks file as “Water_Buffer”)>c.  Distance (value or Field) = check the Field  box and select buffdist>d.  Side Type = FULL>e.  End Type=ROUND (NOTE:  This is greyed out)>f.  Dissolve Type = LIST>g. Dissolve Field(s) = BUFFDIST>OK/Apply (OBSERVE:  A message comes up at the bottom right of the screen saying “buffer”.  When done a green checkmark is shown at the same location at the bottom of the screen and a new layer [Water_Buffer] appears on your map.  Also a buffer feature is now shown on the map.)>Bring the water layer above the buffer layer under TOC (NOTE:  If having issues doing this, through the drag feature, save the initial file and open another, then remove both layers>Then add them back onto the map, but add the Water_Buffer layer first and then the Water layer (OBSERVE:  it now shows up to where you can see both layers and the water layer is not covered up as happened before.)>To make the water layer more visible, change the color to a dark blue including the outline >Turn the Roads and Roads_Buffer Layers on to be able to see all layers at once(NOTE:  In arranging your layers, it may be best to arrange such that the roads is the top layer, followed as shown – Roads>b. Roads Buffer>c. Water>d. Water_Buffer >Save File (Vector Analysis II_AK.mxd under this week’s folder) and move on to step 3.  USING ArcPython TO RUN BUFFER ANALYSIS:  Maximize the ArcMap window to be able to see the ArcPy menu button>before clicking on arcpy menu button, go to the Geoprocessing menu>Geoprocessing Options>Check that the first box is checked “Overwrite the outputs of geoprocessing operations”>OK to close window>click on arcpy menu button (OBSERVE:  Window called Python, comes up)>Type  the first line of code that you need to write when working with ArcPy: “import arcpy” (NOTE:  space between the two but no quotation marks.  If a selection box comes up as you type, double click on the choice of word to add to the type line>Enter key to move to next line>Type “arcpy.(include  the period, but no quotation marks)(NOTE:  drop menu box comes up and this narrows down as you continue to type.  If does not then you may have made a typing error, check your spelling)>Type Buffer_analysis (NOTE:  can  type “buffer” then double click on buffer_analysis to select when it comes up in the drop down menu  box)>Type an Open Parenthesis (NOTE: A window automatically pops up giving you a list of possible “in_features”.   Review notes on commands and using open parenthesis pg. 8 of lab instructions)>Double click on “Roads”>type a comma to move to the out_feature_class>type opening quotation marks>copy and paste in path of Roads_buffer (leave out the ” .shp” part of the path, as it will automatically create a shape file)  file from process summary>type closing quotation marks>type comma >Open quotation marks> type the distance 100>space>type Meters (NOTE:  with initial capital)>closing quotation marks>comma>a selection window pops up, select “FULL” (NOTE:  comes already with the quotation marks so no need to type those>comma (OBSERVE: a second pop up window opens)>select “ROUND”>comma(OBSERVE: another pop up window opens)>select “ALL”>type closing parenthesis (NOTE:  quotation marks and comma, no space [except for the distance] are key in your python commands)>Press enter key(OBSERVE: words Buffer appear on bottom right hand window and message appears to show your results having been successfully added, see message below,

>>>import arcpy

>>> arcpy.Buffer_analysis("Roads",”S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Roads_Buffer”,”100 Meters”,"FULL","ROUND","ALL")

<Result ‘S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Roads_Buffer.shp’>

>>>

PART 2: OVERLAY IN ArcMap

Save and Close File in ArcMap in order to be able to update it’s attribute table in ArcCatalog10 (NOTE:  Will be unable to change attribute table when file is open in ArcMap10, or any file for that matter is open in ArcMap10.  Completely exit from all instances of ArcMap10>ArcCatalog10>under contents tab, right click on file water_buffer.shp>properties>scroll down to empty field and click on the row to highlight Field Name and Data Type (NOTE:  Data Type will be highlighted in Black while the first field, “Field Name” will be highlighted in white)>Start typing (NOTE:  Will begin to type in the first box = Field Name Box>type, “INSD_WBUF” (NOTE: Skip the period as shown in the lab)>Tab to Data Type Column (NOTE: Drop down menu option pops up) – select “short integer”>Reopen file in ArcMap 10>Open  Attribute table (OBSERVE: the new attribute is automatically added to the properties for the water_buffer  layer.  >TO ASSIGN A  VALUE FOR EVERY FEATURE IN THE LAYER:>Skip the select by attribute and scroll to the INSD_WBUF column and right click on column heading>select “Field Calculator Function (OBSERVE:  A Field Calculator window pops up)>Enter the following information in the Field Calculator window: >a.  Parser = VB Script>b.  Fields = Leave as is>c.  Show Codeblock = leave as is>d.  Type = see that Number is checked>e.  Functions = Leave as is>INSD_WBUF = box = type in 1>OK(OBSERVE:  Get a Processing window with the message “calculating records”.   Once done should see all features assigned the value 1 under the INSD_WBUF column>Close Attributes Table and Save file>Repeat for Roads_Buffer layer using 1 for the value and INSD_RBUF for the new attribute>Close  Attributes table and Save file>Open ArcToolbox>Analysis Tools>Overlay>Union (OBSERVE:  A union window pops up.  Follow the instructions to complete):> a. Input Features = One by one, click on Roads_Buffer then Water_Buffer to add to the Input Features Selection>b.  Output Feature Class = S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Buffers_Union.shp (Name the file “Buffers_Union”)>c.  Join Attributes= ALL>d.  Gaps Allowed = Check box>e.  XY Tolerance = leave blank and leave units for meter>OK (OBSERVE:  A message comes up at the bottom right of the screen saying “union”.  When done a green checkmark is shown at the same location at the bottom of the screen and a new layer [Buffers_Union] appears on your map.  Also a buffer feature is now around the initial roads on the map.)>Save File (Vector Analysis II_AK.mxd under this week’s folder) and move on to the next step:  SELECTING RECORDS BY ATTRIBUTE: Under attributes table – click select by attributes and input the following information: >a.  Method = Create a new selection (NOTE:  You can also select from current selection but before doing this you will have preselected  ALL rows in the attribute table – select first row>hold shift key down and scroll to last row and click to select – highlights all columns)> b.  Double click on INSD_WBUF  to drop it in the “select from Buffer_Union where:” box>c.  click on the “=” sign>d. Click on “Get Unique Values” button>e.  Double click on ‘1’ to drop it in the “select from Buffer_Union where:” box>Add the 2^nd query using the “And” button>after clicking the and button repeat the above for INSD_RBUF with a valueof 1 too>f.  verify (NOTE:  A message comes up “the expression was successfully verified”>OK>Apply(NOTE:  only the records that meet the shown query show up)>EXPORT THE SELECTED FEATURES TO A NEW SHAPEFILE USING THE SHOWN INSTRUCTIONS: Right click on Buffers_Union>Data>Export data (OBSERVE: An export data window pops up)>a.  Export = selected features>b. Use the same coordinate system as = check this layer’s source data>c.  Output Feature Class = Path to this week’s folder and save as Buffer_Union_Export>Yes to add new layer to shown map>New layer with the shown name shows up>uncheck all layers but for Roads, Water and Buffer_Union Export>Repeat using the Update Overlay tool (NOTE:  Results are the same)>Move to the final step: SEPARATING AND EXCLUDING AREAS: With ArcMap and ArcCatalog windows both minimized, drag into ArcMap the conservation areas shapefile (NOTE: New layer = Conservation Areas, shows up under TOC and the areas are shown on map)>can modify color – change to green (best for showing conservation areas – personal preference)>Using overlay tool exclude the conservation areas that need protection of plant and animals (NOTE:  Use the Erase tool)>a. Input Feature = Buffer_Union_Export>b.  Erase Features = Conservation_Areas> Output Feature Class = S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Possible_Sites.shp (NOTE:  Record the output under this weeks file as “Possible_Sites”)>OK (OBSERVE: The word Erase scrolls in bottom right of window and a new layer shows up on map called Possible_Sites>NEXT – TURN MULTIPLE PART LAYERS INTO SINGLE PART LAYERS: Right click on the Possible_Sites layer>ArcToolbox>Data Management Tools>Features>Multipart To Singlepart (OBSERVE: A multipart to singlepart window pops up)>Input information as shown: >a.  Input Features = Possible Sites>b.  Output Feature Class = S:\Intro2GIS\WEEK 9_VECTOR ANALYSIS II\Possible_Sites_Single.shp (NOTE:  Record the output under this weeks file as “Possible_Sites_Single”)>OK (OBSERVE: The word Multipart to singlepart scrolls in bottom right of window and a new layer shows up on map called Possible_Sites once the process is done>Add a new attribute to the Possible_Sites_Single table>Close all sessions of ArcMap and be sure you only have on session of ArcCatalog running>From ArcCatolog insert as shown above, a new field “Area” with a type “Double”>Once inserted and back in ArcMap open up attributes table for this layer>select all records>right click on the area column>select calculate geometry (OBSERVE:  A window opens up)>populate window as shown>a.  Property = Area>b.  Coordinate system = use one specified>c.  Units = square Meters (NOTE:  Given that meters has been the linear unit for the shapefiles, for Area we need Square meters>d.  Calculate selected records only = check>OK (OBSERVE:  Window pops up saying calculating records)>once done, the areas of each of the areas is added to the column>To find minimum and maximum use the sort ascending and sort descending features respectively (NOTE:  Be sure to drag the column to allow for the entire width of the column showing all the areas)>deselect the fields>add all the map elements remembering that for the scale and scale text, you should use units>the legend will be made of only 3 items; roads, water and possible_sites_single>Save file>Export as a Jpeg File and lastly archive.

SEE FINAL MAP BELOW