Locating Invasive Species

As drought sweeps across the United States and devastates arid and semiarid areas, invasive plants that use more water than native species are under fire. Saltcedar is considered the one of the worse offenders and grow along rivers in southern Texas and northern Mexico. In order to gather accurate data on the number and location of invasive species, remote sensing has previously been used in Texas and Florida. In order to find the most effective method for detecting saltcedar, the remote sensing types, high spatial resolution data, hyperspectral data, and moderate resolution-imagery were compared while studying a small area along the Rio Grande.

In preparation, researchers went on foot and logged locations of the desired species using GPS to create points and polygons and used their observations to create 16 classes of land cover.The five pixel based programs studied would place each pixel into one of the land cover classes and then further classify these into one of three categories: invasive species, native species and clear.Afterwards an assessment of the accuracy was done by overlaying the results with the gathered points and polygons. The Researchers found that hyperspectral data was the most accurate, but required more care when processing the data.

 Le Wang, José L. Silván-Cárdenas, Jun Yang & Amy E. Frazier (2012): Invasive Saltcedar (Tamarisk spp.) Distribution Mapping Using Multiresolution Remote Sensing Imagery, The Professional Geographer,
DOI:10.1080/00330124.2012.679440