Hello from the field. I am traveling this week with Kim Pham, Ian Kracalik, and Ann Espejo. Kim and Ian are masters students in Geography and Ann is an undergraduate student. We are also joined by Dr. Martin Hugh-Jones, emeritus professor, from Louisiana State University. This week we are working from South Texas on ranches near Falfurrias and Hebronville to continue our work on the ecology of zoonotic diseases. Specifically, we are working to ground truth some remote sensing work we have developed. We have been working with Landsat 7 ETM+ and Landsat 5 satellite images to identify a unique habitat known as coastal potholes. These potholes are low lying depressions that collect water, soil, and organic material and provide great habitat for deer and cattle to dodge the heat. Martin and I have been working since 2003 to identify these habitats and to develop a methodology to delineate them from remotely sensed images. As part of our efforts, Martin and I have returned to several key potholes repeatedly to collect soil samples, measure plant abundance, and evaluate animal usage of these habitats. As part of our efforts, we have been using the tassel-cap transformation on Landsat images and using these outputs to identify known potholes and then estimate locations of unknown potholes. We couple this remote sensing effort with field data and handheld PDA-GIS (ArcPad and various PDA technologies) to travel to estimated potholes and confirm their presence in the imagery.
Since the fall of 2007, Kim and I have been expanding the research methodology to include more significant plant taxonomy of species Martin and I have used to delineate potholes and the inclusion of NDVI in addition to tassel-cap. Additionally, Kim and I have working to describe the seasonality of potholes from the t-cap analyses using images from multiple seasons across a two-year period.
This week we are here to ground truth our more recent efforts and expand our plant sampling. As part of this, Ian and Ann have joined our research team. Ian also has experience with handheld PDA technologies and is working closely with me to capture field data and navigate across the imagery. As part of this Ann is joining us to learn some of our field methodology and explore biogeography and medical geography in a single trip.
