Searching for Trout_GIS Applications- FINAL Project-

Our goal for the final project was to create a location scenero applying weighted criteria techniques to determine optimum sites for the project.   The following is the search for a year round trout stream community center in Fannin County, Georgia.  This post is the powerpoint presentation in slide format.  Methods and analysis follow along with my references less the slides which are included in the presentation to prevent redundancy.  

 

Methods & Analysis:

Methods:

Study Site:

              Fannin County lies on the Georgia-Tennessee line.  The largest water body is Blue Ridge Lake created in the 1930's now operated by the Tennessee Valley Authority.  Out of 391.43 square miles only 5.69 square miles are water bodies.  Although Fannin County is not large in size nor high in population, it has 10.24 percent out of the  5,437 miles of designated trout streams within the 25 county trout stream region.  More than 63 percent of the designated trout streams are under private ownership. ( DeMeo,T.A, Christy, D.R & Kundell, J.E. 2005).

              The northwestern area of Fannin County east of McCaysville has a large catch basin with year round permitted trout fishing.  This catch basin (Fightingtown Creek) flows north into the Tennessee River basin and will be our initial target area unless the data leads us to other viable regions in the county.    

Data Requirements/Sources:

·        Trout Streams in Fannin County, GA   (site: wildtroutstreams.com has GIS data) depicted below in green was used as base information and location.  Specifically the corridor on northwest side which  has year-round trout fishing was the targeted zone (corridor of Hwy 207, 127, 2, 210, 159, 212. Primarily the catch basin of Fightingtown creek).   See area below:

·       Most of the general data was obtained through the USGS (U.S. Geological Survey)website, linked through to state specific data, ours being the Georgia Spatial Data Technology.  http://csat.er.usgs.gov/statewide/downloads.html  Unfortunately, on August 1, 2012 the links to the state specific data was disabled due to lack of funding.   There was additional data this GIS Analyst expected to obtain namely the DOQQ series for Fannin County, Georgia  and other data clarified before the final product was to be turned in. This did not occur. Alternative forms of aerials was obtained.

Most of the USGS data was converted from Clark 1866 to NAD 1983, some was originally NAD 1927 which was also converted to NAD 1983.

·       The final projection and project projection chosen was  Albers Equal Conical Area, Datum: D North American 1983. Most of the USGS data and the individual Georgia data from the Georgia GIS Clearinghouse and geocommunity.com were also in North Americas Albers Equal Conic.

·       As the data was evaluated it divided into two groups, those scaled very large based on the US Atlas series and those based on an individual state scale.  A list of the data is below:

              GNIS for State of Georgia, 1997, point of accuracy 40 meters.

              Counties of Georgia, from US Census/TIGER-, 1996  The project will use the Fannin County, GA

                                           extent as its basis for all clips & raster extraction, accuracy 40 meters

               

              USGS, topo maps in digital raster, from 1975, accuracy 40 meters

              USGS-Georgia Cities & Towns, from US Census/TIGER, 1995, accuracy 40 meters

              USGS-Georgia Elevation, DEM, at 250, 1987, 3x3=1 degree,

              USGS- Georgia Slope, 1987, scale 1:100,000

              Georgia Soil Survey, 1994, accuracy 1230 meters, scale 1:250,000

Conservation lands, reference Georgia GAP Project, 1999, accurate as 1:12000, public owned lands w/o natural areas not included, not inclusive of all historic sites.

Georgia- Landuse 1 & Landuse2, Land use from 1972-1975, accuracy between 10-40 acres, scale 1:250,000

USGS, Georgia State park & Historical Sites, updated 12/1998, accuracy to 40 meters.

USGS, River Basin Management Planning, file 06020003, Tennessee River Basin,  NAD 1983.

Trout stream information from wildtroutsteams.com,  georigiaoutdoors.com, and georgiawildlife.com.

             

Analysis: 

              This project was accomplished using GIS analysis based on specific criteria to locate potential Sites for the community center.  Specifically, conditional raster analysis through the spatial analyst extension in ArcGIS Map Version 10, was used.  Conditional raster analysis  evaluates each raster cell assigning it a true or false value based upon an established  query.   In our case the DEM (elevation) layer was queried for Elevation 674 or less and with a second value of 675 to 800.  With the Slope raster, it was divided into Slope less than 6 percent and slope from 6.1 percent to 8 percent.  Alternatives were given at the time of evaluation to allow for alternative sites if the original values did not produce results.  The evaluation was conducted using a model form.   An issue arose when the original selected clipping layer (Fannin Co) was a different scale from the originating rasters in the conditional raster argument. After a new clipping layer was found, the conditional raster model was rerun without difficulty. 

Once the Elevation and Slope rasters were converted to shapefiles the second evaluation portion could be initiated.  A Fannin County base map was established using North America Albers Equal Conic as the projected coordinate system for the model.      For each map, map properties were established, environments were set using the original State of Georgia DEM 250 as the extent and coordinate system.  

              A State of Georgia base test map was established to view data.  Fannin Co, isolated for the raster model was used to clip several layers:  hydro, forest, GNIS, roads, etc.   After the base layers of Fannin County were established, evaluation began.  Elevation and slope intersects were placed on the base map, then streams. As the results began to appear county wide, potential areas for sites were coming into view.   These evaluations were created and outputs made:

Elevation/Slope:   (Results Map )

              1- Intersect between Elevation 675-800 with Slope under 6

              2- Intersect between Elevation 675-800 with Slope 6-8 (as an alternative was not needed)

             

 Year Round Streams: (Incorporated as layer file in Maps):

            3. New feature class for year round streams was created, digitized using the paper  Fannin       County Trout Streams by Georgia WildLife.com as a guide with the hydrology layer.

              4. Streams in Year round layer were buffered to 300 feet.

              Private Lands:   (Results Map)

              5. Forest layer added showing Federal and private lands,  private lands isolated.

              6. Buffered year round streams and output of Elevation/Slope6 were intersected.

              7. Private lands intersected with output of Elevation/Slope6/Buffered.

An overview of Fannin County with the addressed roads showed the absence of county roads in the western region which is primarily federal conservation land.  It was this revelation which added an additional criteria to separate out privately owned land which was listed as a field in an attribute table.  

Once criteria sites were identified, these visuals were printed out, then using shape points, the GIS Analyst was able to locate common points using georeferencing techniques.  A common point was either a static point on the boundary line of the federal lands or a point on the streams.  Geographic coordinates were available on  qpublic.net the official tax property parcel website for Fannin County, Georgia.   Using a combination of matching points and Google aerial maps, sites were  absolutely located  to physical locations on the official Fannin County property map.    Although the site parcel  polygons did not match any property parcels exactly,  the GIS analyst was able to coordinate the sites to common tax property parcels containing portions of the desired site location.   This was quite fortunate due to an unexpected difficulty in obtaining orthiomagery for the site parcels. Funding  cuts with USGS  occurred on August 1, 2012 which affected the retrieval of orthoimagery, additional web sites where affected as well.  Notwithstanding the unexpected, Google Earth, enabled retrieval of aerial images.     For each of the sites, A, B and C, a series of evaluations were made to satisfy Objectives Two and Three. 

The last step in the analysis process was to apply a weighted analysis to several of the criteria.

1. The school, church, community layer was converted into a raster, then reclassed. However, the reclassing did not result in the attributes being ranged from near to far, but randomly spread out.  This does not work for our purposes.   Since there have been numerous issues with preparing this feature to raster etc. the weighed analysis has not been successful.

2. The roads layer was also converted into a raster, then reclassed. Checking the attribute table the roads are classed from near to far, which works properly.

3. Euclidean Distance was performed on each Site point, A, B & C. Each point was reclassed as an individual raster.

4. A model was set up for the weighted analysis.  For each run of the model the school and roads input remained the same.  Each point was entered as a parameter and the output was renamed accordingly. After review, the results were void, see description of school layer above.

5.  In light of the model issues, a weighted chart was created.  Several criteria in Objective 2 & 3 had to be evaluated using visual analysis.  A weighted chart was created for this. Same Chart as in conclusion Above.

Conclusion:

Using the criteria set out by the client, three viable sites were found in the target area using GIS Analysis over and above the usual search conducted by real estate agents.   Each possible site was located on the ground using georeferencing techniques through the use of Google Earth and the Fannin County Tax Assessor's web portal, qpublic.net. 

A weighted analysis was used through visual inspection of the properties centering on Objectives two and three which required special application of the criteria.   Applying the weighted analysis revealed potential issues with the sites before actual trips to the physical locations were planned, saving both time and money.