method/project_update

Methods:

                It took a considerable amount of time to install ArcGIS onto the computer. Part of the problem was forgetting to connect to the VPN the other issue was establish the license through arc administrator. Once installed everything worked well; except the spatial analyst tools. I attempted to install the service pack to fix the issues but that didn’t seem to work. I put aside the spatial analyst component and began by adding layers and importing them through ArcCatalog. I then converted the raster layers to pyramids and put the vector layers into a file geodatabase. I created two geodatabases to store my data. One was created as a workspace, while the other was created to hold more refined layers. All of the data, downloads and manipulated files, are kept in one folder on my external hard drive. Organization is one of the biggest challenges and certainly essential to success.

                Next I put everything into Arc Map. I changed the projections all to VT State Plane NAD83. I also converted the county boundaries into raster format. This was fairly simple; it required opening the polygon to raster tool and placing the vector layer in. I added a new data frame to hold the initial layers. In addition as I continued to process layers I attempted to keep only the newest and most relevant in the active data frame. The relative level of layers stayed the same in the active data frame. The other data frame accumulated quite a few layers due to all the intermediate steps and trial and error. When I left my computer for a couple hours ArcMap stopped working when the vpn disconnected, I lost a little bit of work. When I returned I enabled the spatial analyst using the “customize” menu then “extensions”.

                Then I used Euclidean distance to get the distance to roads. It allowed the conversion of a vector road layer into raster format. It seemed to work alright; however, I wasn’t able to clip it and the number of categories and classifications seemed really weird. After much trial and error I still wasn’t able to clip the layer correctly. I used the environments- processing extent (raster counties) and snapped to raster counties. The result was a rectangular shape. After researching I decided to use “extract by mask” to essentially clip the layer. Essentially this tool is like placing a mask on a piece of paper and only removing the area covered by the mask. By putting the layer into “in_raster” that you want to extract from, and placing the mask layer into “in_mask_data” the raster layer is restricted to the desired  area. I used the extract by mask tool for three layers: land use in 1992, land use in 2001, and the distance to roads (raster) layer. For all three of the processes I used the raster county layer as the input for “in_mask_data”. The land use layers were for the entire Champlain Valley. The “extract by mask” tool allowed the left border to be restricted to Vermont’s western border. Finally I classified the distance to roads with equal distance. I arbitrarily created 16 different intervals to show a greater and more specified range.

In The Future:

                While I am still waiting on data from VLT I may use a protected areas layer to proceed. This way I could build the model and experiment with various components. When I get the VLT data I can simply substitute it for the other data. As of now I have got all my data into ArcMap. It is all in the same projection, datum, raster, same cell size and clipped to the same extent. Theoretically all my data is ready to go and be entered into the model. The next step will certainly be difficult, because I am more comfortable with ArcGIS than Dinamica. The other major challenge is that ArcGIS has an abundance of online help, while Dinamica only has an email list. I may also need to find land use data on the entire state. This could be difficult.

Try using the functor “determine Transition matricies” and placing the two different years of Lake Champlain land use into it. 1992 should connect to the initial landscape port and 2001 should connect to the Final landscape port. The result should be a single step and multi step matrix. The number of time steps should correspond to the number of years. This would mean 2001-1992 = 9.