Mapping

The goal of the ongoing Yale Forests mapping effort is threefold:

1. Create updated stand boundary and stand type maps of all of the Yale Forests by utilizing a combination of Global Positioning System (GPS) and Geographic Information System (GIS) technologies coupled with our most recent inventory data.

2. Locate and map all boundaries, roads, skid trails, and water bodies throughout the Yale Forests using GPS and GIS.

3. Create an established system for updating these maps and for regularly using GIS for stand delineation, locating and planning timber sales, and establishing research plots.


Yale Myers GIS
Yale Toumey GIS


Mapping Manual
Currently there are two primary maps which are frequently utilized on the Yale Forests. One is a stand type map of the Yale Myers Forest which was created in 1945, and the other is a stand type map of the Yale Toumey Forest created in 1940. Soil Survey maps are also used and are found in the Tolland and Windham County Soil Surveys. The USGS Topographic 7.5 minute quadrangle maps which are used are the Eastford and Westford Quad maps. These maps have been invaluable in the past four decades and will undoubtedly continue to be so, but it is becoming increasingly important to create new, updated maps based on current inventory information. This is especially true in the case of the Yale Myers Forest, where commercial thinning and regeneration treatments are now being prescribed after decades of firewood and timber stand improvement harvests. Up-to-date maps of the stand types, ages, and volumes will aid in management decisions in the future. It is important to keep the existing maps of the Yale Myers and Yale Toumey Forests archived in the system.

Utilization of Geographical Information Systems
The implementation of GIS into the Yale Forests started in 1995 when a graduate of the school, Jody Rowlands, did much of the initial work on the Yale Myers Forest. The base outline of property boundaries was taken from the 1945 map of the property and then digitized in Arc Info by Rowlands. A digital elevation model (DEM) was also created by Rowlands, in this case from a USGS topographical quadrangle map, and an interpolation of the vector map of contour lines generated a smooth, continuous rastor image of height. Boundaries of management divisions also came from Rowlands' work. Rowlands was able to get soils, water bodies, wetlands and roads data from the state. This information originally came in the form of digitized 7.5' quad maps, but can easily be clipped to the area of interest. Many students have used these baseline maps for projects on the Yale School Forests. One project focused on stand delineation within the Pulsnin division, while another looked at remote sensing data and Yale Myers. The 1940 map of Yale Toumey has been scanned into GIS and its stands digitized, but the other parcels of the Yale Forests have not been addressed at this time. The following is a list of items that are still needed to complete the baseline data of the Yale Forests in GIS:

1. Property boundaries, wetlands, water bodies, streams, and roads of the Bowen Forest, Crowell Forest, Goss Woods, Cross Woods, and Crowell Ravine.

2. All skid trails for all parcels.

3. Permanent research plots, especially at Yale Myers.

4. Inventory data from the operational cruise on the French and Curtis Divisions (collected in the summers of 1994 and 1995 successively) should be entered into GIS and stand boundary maps created.

Futher Analysis of Yale Forests GIS Data

Procedures
Collecting information with a GPS. The collection of data points with a GPS for use with ArcView has been done and should not be too difficult but unfortunately the procedure has not been codified.

Stand delineation
Much of the actual stand identification will require hard copy aerial photos. However, once the stand differences have been identified a stand map can easily be drawn in the GIS. Digital aerial photos are now available to aid on screen digitizing. The digital aerials can be brought into ArcView GIS as an image with the image extension turned on. Once the aerial photo has been added to the view its placement and size can be made to match the GIS layers by changing its world file. The GIS layer of the division can be edited to depict the stands with the digital aerial photos as a guide, or backdrop for the digitizing. For more information please see the ArcView online help.

Entering inventory data into ArcView
As mentioned in the Sampling Section the inventory maps could be automated with ArcView by creating a theme of inventory points. One of the advantages of creating a sampling grid with the GIS is once the inventory has been collected the information can easily be entered back into the GIS. It probably makes sense to run the inventory data through YMF tally before entering it into the GIS. The inventory data should be entered within the inventory plot coordinate table. Index numbers might make this process easier.

Creation of new stand type maps
With the inventory data as well as stand boundaries in a GIS it would easy to summarize the stand type depicted by the inventory points for each stands. For help doing this look in the ArcView manual for summarizing zones.

Choosing timber sales
Other statistics such as the average board feet per acre could help in the selection of timber sale areas. Any GIS layers of research plots should be consulted to determine their impact on a sale area. Research plot areas can be compared to sale areas by adding them both to the same view.

Creating maps for proposed timber sales
Once an area has been selected for timber sale a GIS map should be made both for the bidding processes as well as historical record. To create a map of a sale area the division map or stand map should be edited to reflect the sale area. Once a theme of the sale area has been created other themes could be added to the view. Roads, water, and contours all help describe the sale area. In addition skid trails and wetland buffers could be digitized or generated.

Yale Myers GIS Data

Forest Boundary
Forest Stands
The Study Area Boundary
The 1945 Yale Myers Stand Map
Rivers (updated)
Roads (updated)
Township Boundaries
Water Bodies
Watershed Basins - Metadata
Surficial Materials - Metadata
Soils - Metadata


Much of the GIS data presented here is taken from the University of Connecticut MAGIC map library, which was originally generated by the USGS. The maps form part of the Digital Line Graph data set, which are basically digital version of the 7.5 Minute topographic maps produced nationwide by the USGS. The Yale Myers Forest falls in the Eastford and Westford quadrangles. For easy of use the quads have been joined together and then clipped to just the area surrounding YMF. All the GIS data sets available here are in the UTM projection using the 1983 datum (NAD83). The scale is effectively 1:24,000 and the accuracy meets national map accuracy standards. The unmerged, uncropped USGS quadrangle maps for Eastford and Westford are available for download from the UConn MAGIC site.

Vector data is in shape file format for ArcView and have been compressed for easier downloading into the zip compression format. To decompress use WinZip or similar decompression program. For viewing use ArcView or a free program called ArcExplorer is available.

Forest and study area boundary, forest stands, and 1945 stand map were produced by the Yale School Forests. Rivers, roads, township boundaries, and water bodies come from the USGS. Watershed and surficial material data comes from the Connecticut Department of Environmental Protection. Soils data courtesy of the Natural Resources Conservation Service.

Yale Toumey GIS Data

Airport
Ashuelot River
Cheshire County Boundaries
Hydrology
Lakes
Public Land Survey Boundaries
Railroads
Roads
Soils
Utilities
Yale Toumey Boundaries


In an effort to provide a base for mapping the Yale Toumey Forest, a series of GIS maps have been created and made available here for public use. The free down site US GeoData provided a series of USGS base maps. These base maps form part of the Digital Line Graph data set, which are basically digital version of the 7.5 Minute topographic maps produced nationwide by the USGS. All the GIS data sets available here are in the UTM projection using the 1927 datum (NAD27). The scale is effectively 1:24,000 and the accuracy meets national map accuracy standards.

Vector data is in shape file format for ArcView and have been compressed for easier downloading into the zip compression format. To decompress use WinZip or similar decompression program. For viewing use ArcView or a free program called ArcExplorer is available.

The original STDS format files are available here. Metadata explaining the DLG is available here. The soils and Chesire county boundaries information comes from the Natural Resouce Conservation Service and their SSURGO database. The SSURGO site also has an explanation of the data codes and metadata explaining the soils dataset. The Yale Toumey boundaries were digitized using the 1940s stand map and the USGS roads layer as a base.

The raster data sets are in GRID format for ArcInfo and ArcView with Spatial Analyst. ArcView requires the Spatial Analyst extension to deal with grids. The grids are in export format must be imported using the import71 program for ArcView. The original STDS format files are available here. Metadata explaining the DLG is available here.

The stand map of the Yale Toumey forest was drafted in the 1940s using an unknown projection. In order to be able to use this image in a GIS it has to be brought into a projection. The rest of the data sets use the Universal Transverse Mercator projection with the NAD27 datum, so the stand map was warped to fit that projection as well. below are the rectified image and the accompanying world file which allows the image to be read in ArcView. Discrepancies exist between the 1940s stand map and the USGS base maps. For example, the river follows a different course in each map. These differences are no doubt due to the time difference between the two maps.

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