A Weed Manager's Guide to Remote Sensing and GIS
Predicting Weed Spread and
Areas Susceptible to Weed Invasion
How Can I Make the Biggest Impact with Limited Funds?

Predict weed spread and vulnerability to invasion. By predicting weed spread and vulnerability to invasion, you can plan the most effective use of your resources. For example, in year 1 of the 100-year animated simulation of perennial pepperweed spread (above), treating the three smallest patches would likely have a greater impact than treating the larger (upper right-hand) patch because it is unlikely to spread.
Weed Impacts

Conventional color aerial photography of a rangeland infested with huisache near Sinton, Texas. The arrow points to the characteristic golden image of huisache in flower.

(Photo courtesy of James Everitt, USDA-ARS).
Predict Areas Susceptible to Invasion
Weed susceptibility models are used to predict the vulnerability of certain areas to invasion by specific weeds, if introduced. Such information helps managers focus management efforts on potential “hot spots.”
The easiest way to predict where a particular weed is likely to invade is to adapt an existing model to your particular location and specific weed. Learn how [PDF]...
If existing models are not available, you can develop a simple GIS model to predict areas susceptible to invasion by a particular weed species. Learn how [PDF]...
Habitat suitability for leafy spurge invasion was modeled for the Fishlake National Forest. Most known patches of this weed occurred in areas predicted to be highly suitable to invasion. Learn more [PDF]...
Predict Weed Spread
Even with a ground-surveyed map, it is not easy to know which infestations will spread faster than others. Weed spread models help weed managers visualize the rate and limits of spread, allowing them to prioritize treatments.
A relatively simple way to predict the spread of an existing weed infestation is to adapt an existing model to your location and weed. Learn how [PDF]...
If existing models are not available, you can develop a simple GIS model to predict the spread of existing infestations in your area. Learn how [PDF]...