HR: 0800h
AN: H31A-0131    [Abstracts]
TI: Estimates of Water Use of Saltcedar (Tamarix ramosissima) on the Lower Colorado River: from Plant to Stand to River Reach
AU: Glenn, E P
EM: eglenn@ag.arizona.edu
AF: University of Arizona, Environmental Research Lab, 2601 E. Airport Drive, Tucson, AZ 85706, United States
AU: * Nagler, P L
EM: pnagler@usgs.gov
AF: U.S.G.S. SWBSC, Sonoran Desert Research Station, 125 BioSciences East, Tucson, AZ 85721, United States
AU: Didan, K
EM: kamel@ag.arizona.edu
AF: University of Arizona, TBRS, 125 Shantz Bldg., Tucson, AZ 85721, United States
AU: Osterberg, J
EM: JOSTERBERG@do.usbr.gov
AF: U.S. Bureau of Reclamation, Denver Federal Center, Denver, CO 80211, United States
AB: Saltcedar (Tamarix ramosissima) removal projects have been proposed to salvage water that would other wise support saltcedar evapotranspiration (ET), and to allow native vegetation to recolonize western U.S. riparian corridors. We measured stem-level sap flow at Cibola NWR on the Lower Colorado River to answer some of the scientific questions about the possible consequences of saltcedar removal. We then conducted wide-area studies using remote sensing technology by scaling from the three ground sites using TM- and MODIS-based ET estimates. The sites were different distances from the river channel and differed in depth to water table and salinity of the ground water. Results were then extrapolated to the river reach (from Davis Dam to the delta of the river in Mexico). Saltcedar stands at Cibola had moderate rates of ET, based on remote sensing estimates, averaging 1.1 m yr-1, similar to rates determined for other locations on the river and for other river systems. Leaf area index (LAI) values were also moderate, and stands were relatively open, with areas of bare soil interspersed within stands. Despite high ground water salinity (5,000-10,000 mg l-1), the sites away from the river did not have saline surface soils, supporting studies showing that saltcedar does not salinize riverbanks. Approximately 1 percent of the mean annual river flow is lost to saltcedar ET on the Lower Colorado River in the U.S. Based on these results, the opportunities for water salvage through saltcedar removal appear to be constrained by its modest ET rates.
DE: 1640 Remote sensing (1855)
DE: 1813 Eco-hydrology
DE: 1814 Energy budgets
DE: 1818 Evapotranspiration
DE: 1855 Remote sensing (1640)
SC: Hydrology [H]
MN: 2007 Fall Meeting