Monitoring macrophytes cover and taxa in Utah Lake by using 2009-2011 Landsat digital imagery Article

Rivera, S, Landom, K, Crowl, T. (2013). Monitoring macrophytes cover and taxa in Utah Lake by using 2009-2011 Landsat digital imagery .(39),

cited authors

  • Rivera, S; Landom, K; Crowl, T

fiu authors

abstract

  • Macrophytes serve a valuable function in lake ecosystems; they stabilize sediments and associated nutrients, and they provide important habitat for fish and wildlife. As such, the coverage and taxa composition of macrophytes have been selected as priority parameters for monitoring the Utah Lake ecosystem. The goal of this project was to develop a macrophyte monitoring procedure for Utah Lake' tributary watershed using Landsat imagery to map macrophyte vegetation distribution around the lake. We first used a combination of GPS points collected in the field and points extracted from a high resolution image to train a macrophyte distribution model. Some 500 GPS points were divided into four categories: 1. Open water, 2. Phragmites australis, 3. Typha latifolia (Bullrush) and 4. Terrestrial vegetation. We then established the spectral signatures and statistically isolated the four categories. Finally, we employed a hybrid classification, a combination of supervised (SEE-5 software) and unsupervised classifications to isolate the pixels representing the four classes. After several attempts a preliminary model showed a 74% and 78% mapping accuracy for Phragmites australis, and Typha latifolia (Bullrush) respectively. It also showed an overall mapping accuracy of 67% for the four classes. There is an ongoing process to improve model's accuracy with more field data. Once our macrophyte model is calibrated, we plan to map historical macrophyte distribution and taxa composition using a 1984-2012-time series of Landsat images. The proposed procedure has proven invaluable to Utah Lake ecosystem monitoring efforts.

publication date

  • July 30, 2013

issue

  • 39