Using Geospatial Tools to Assess Urban Tree Canopy

landcover viriginaClassified tree canopy layer in the Virginia Urban Tree Canopy Mapper –

Urban forests can be defined as the sum of all woody and associated vegetation in and around dense human settlements (Miller 1997). The people living in and around urban forests receive many direct and indirect benefits, such as the cooling effect of strategically placed trees around a house or the reduced costs of storm-water management (Konijnendijk et al. 2005). In order to estimate the social and ecosystem …

QGIS: Free and Open-Source GIS Software

qgis header logo

Quantum GIS (QGIS) provides much of the same functionality as Esri’s ArcGIS software (basic level) and has developed into a robust open-source alternative. The term open-source refers to the fact that the source code for the geographic information system (GIS) program is available to anyone, so people can try to improve and add to the software. The QGIS coding community has worked diligently to improve the program and add features in recent years.

How to Learn More about QGIS

There …

Sharing Content in ArcGIS Online: Public and Organization Accounts

University of Rhode Island Environmental Center Screen Capture


Big Changes for ArcGIS Online 

ESRI has made two important changes to the ArcGIS Online platform: an account name change and a new account option.

  • Account name change: An ArcGIS Online account, once called a personal account, is now referred to as a public account
  • A new account option, referred to as an organization account, has been created. This account type requires a subscription to ArcGIS Online for Organizations. There is a cost associated with this account

What is mobile GIS?

Mobile GIS is taking Geographic Information Systems (GIS) out of the office and into the field. A mobile GIS allows folks out in the field to capture, store, update, manipulate, analyze, and display geospatial data and information. Mobile GIS integrates one or more of the following technologies: * mobile devices (such as a PDA, tablet, or laptop computer, and in some countries mobile phones) * Geographic Information System (GIS) software * the Global Positioning System (GPS) * wireless communications for …

Topography and Understanding Topographic Maps

usgs topographic map


Among the many mapping tools available, the most commonly used is the topographic map. Topography is defined as the relief (relative elevations) of a surface and the relative relations between its natural and man-made features. Topographic maps systematically portray the spatial relationship among both the physical features, such as contour lines (lines of equal elevation) and hydrographic symbols, and cultural features, such as roads and administrative boundaries. Topographic maps are also known as “topo maps.”


Reading a topographic map begins …

The Role of GIS in the National Gypsy Moth Slow the Spread Project (STS)

The gypsy moth is a serious invasive pest of hardwoods. A native of Europe and Asia, the insect was accidentally released in the United States more than 130 years ago near Boston, Massachusetts, and has now spread into the mid-Atlantic and midwestern states. Populations are cyclical, with periods of low abundance and periods of outbreaks. Since the first reported defoliation in Virginia in 1984, more than 5.3 million acres have been defoliated in the state, with treatment costs alone over …