Presentation for the Penn State Mont Alto Offered Student Reception, April 7, 2018
Foresters spend a lot of time in the field studying forest conditions and carrying out management activities from tree planting to timber harvesting.
It is also important to be able to see the whole forest from a distance to save time and money, and to better understand the resources.
Here are a few resources that we use to study the forests of Pennsylvania that are free to use for everyone.
Starting in the 1930’s aerial photos were taken on film from airplanes flying in back and forth patterns to cover part of the landscape. Many of these photos taken by the USDA are now available at the Penn Pilot website. You can look at photos from all over the state at different time intervals. The images can be downloaded and georeferenced in a GIS. http://www.pennpilot.psu.edu/
Google Maps is an evolving source of current imagery. It is updated frequently, so you never know what you will get. If you link it to your Google account you get access to a variety of navigation tools. maps.google.com
Google My Maps let you create your own maps that can be shared on a website or sent to anyone. https://www.google.com/maps/d/ For example, here is a map I made of places I worked in Africa.
Pennsylvania has a spatial data clearinghouse called PASDA, where there is a huge range or geographic data that can be viewed or downloaded. It is used by public agencies, private companies, and interested people. In forestry classes we often download or stream data from PASDA for GIS projects.
Two of the most useful tools in PASDA are the Imagery Navigator and the Pennsylvania Atlas. They show similar data, but vary in how they present it.
Some of the types of data we use include:
- panchromatic (black and white)
- true color at different times and resolutions
- false color or near infrared, good for studying vegetation
- hillshade, which is a shadowed view of the topography developed from lidar
- state and local roads
- soil type maps
- streams and watersheds
- state park, state forest and state game land boundaries
- digital elevation models (DEM) to make contour lines and study topography
- topographic maps
We also use satellite imagery, but that’s for another presentation.