HR: 0800h
AN: B31B-0223    [Abstracts]
TI: Tamarisk (Salt Cedar) Infestations in Northwestern Nevada Mapped Using Landsat TM Imagery and GIS Layers
AU: * Sengupta, D
EM: dsengupta@arc.nasa.gov
AF: DEVELOP Program, NASA Ames Research Center Earth Science Division Mail Stop 242-4, Moffett Field, CA 94035-1000 United States
AU: Geraci, C
EM: cgeraci@att.net
AF: University of North Dakota, Department of Geography P.O. Box 9020, Grand Forks, ND 58202-9020 United States
AU: Kolkowitz, S
EM: dunno6000@gmail.com
AF: DEVELOP Program, NASA Ames Research Center Earth Science Division Mail Stop 242-4, Moffett Field, CA 94035-1000 United States
AB: Tamarisk, also known as salt cedar (Tamarix sp.) is a prevalent invasive species that has infested many riparian areas in the southwestern United States. Mature salt cedar plants are resistant to high stress environments and fare well in drought conditions, mainly due to their extensive root systems that derive much of their sustenance from the water table rather than surface water and precipitation. The salt cedar root systems have altered hydrological patterns by tapping into underlying aquifers. This has decreased water available for recreational use, regional ecology and plant diversity. Many states have implemented salt cedar monitoring programs at the local level, but the problem of large-scale mapping of this invasive species has continued to be a challenge to land management agencies. Furthermore, inaccessible and unexplored areas continue to be absent in the mapping process. In August 2004, using field data consisting of large areas as training sets for classification of Landsat TM imagery, the DEVELOP student research team at NASA Ames Research Center generated a preliminary map of areas that that were susceptible to salt cedar growth for a region in northwestern Nevada. In addition to the remote sensing-based classification of satellite imagery, the team used the variables of elevation and estimated distance to the water table in conjunction with collected field data and knowledge of salt cedar growth habits to further refine the map. The team has further extended the mapping of key environmental factors of water availability for salt cedar, soil types and species distribution in regions infested by salt cedar. The investigation was carried out by 1) improving an existing GIS layer for water access using a suitable interpolation method, 2) including a GIS layer for soils associated with salt cedar growth and 3) completing field work to evaluate species distribution and regions of presence or absence of salt cedar. The outcome of this project served to improve the salt cedar mapping methods already in place in Nevada, to create a guideline for future salt cedar management efforts and to evaluate the usefulness of satellite imagery in the detection of an invasive species. The results will be presented through both the final maps and visualization.
UR: http://develop.larc.nasa.gov
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting