Evapotranspiration, Water Table Fluctuations, and Riparian Restoration: Report Documentary 2007-2008 Work
NEW MEXICO UNIV ALBUQUERQUE DEPT OF CIVIL ENGINEERING
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Water use by riverside phreatophyte ecosystems, also referred to as evapotranspiration or just ET, makes up a significant proportion of a river basins water budget depletions. As phreatophytes, riparian plants access groundwater for their water supply. The objective of this study is to characterize ET depletions from various representative riparian land cover types and to describe the groundwater-vegetation interactions that relate ET to local hydrology. Measurements of ET and groundwater are made at various locations within the city of Albuquerque, NM, and along the Middle Rio Grande. ET is measured from eddy covariance flux towers and groundwater levels are continuously monitored using commercially available submersible pressure transducers. Results show that modest water salvage can be claimed from riparian restoration projects that are properly implemented while additional water losses are possible when necessary followup is not undertaken. Bare soil is shown to lose less water to evaporation than previously expected, and urban hydrology e.g., waste water return maintains high ET rates in whichever species grow in the outfall. Remote sensing of riparian vegetation clearly shows the effects of fires in the urban reach, the initial decline in vegetation density, leaf area index, and ET. This research illustrates the importance of identifying the hydrologic and vegetative factors controlling ET in a large, urban river system.
- Physical and Dynamic Oceanography