Short-term and long-term evapotranspiration rates at ecological restoration sites along a large river receiving rare flow events

Hydrological Processes
By: , and 

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Abstract

Many large rivers around the world no longer flow to their deltas, due to ever greater water withdrawals and diversions for human needs. However, the importance of riparian ecosystems is drawing increasing recognition, leading to the allocation of environmental flows to restore river processes. Accurate estimates of riparian plant evapotranspiration (ET) are needed to understand how the riverine system responds to these rare events and achieve the goals of environmental flows. In 2014, historic environmental flows were released into the Lower Colorado River at Morelos Dam (Mexico); this once perennial but now dry reach is the final stretch to the mighty Colorado River Delta. One of the primary goals was to supply native vegetation restoration sites along the reach with water to help seedlings establish and boost groundwater levels to foster the planted saplings. Patterns in ET before, during, and after the flows are useful for evaluating whether this goal was met and understanding the role that ET plays in this now ephemeral river system. Here, diurnal fluctuations in groundwater levels and MODIS data were used to compare estimates of ET specifically at three native vegetation restoration sites during 2014 planned flow events, while MODIS data was used to evaluate long-term (2002 – 2016) ET responses to restoration efforts at these sites. Overall, ET was generally 0 - 10 mm d-1 across sites and although daily ET values from groundwater data were highly variable, weekly averaged estimates were highly correlated with MODIS-derived estimates at most sites. The influence of the 2014 flow events was not immediately apparent in the results, although the process of clearing vegetation and planting native vegetation at the restoration sites was clearly visible in the results.

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Publication type Article
Publication Subtype Journal Article
Title Short-term and long-term evapotranspiration rates at ecological restoration sites along a large river receiving rare flow events
Series title Hydrological Processes
DOI 10.1002/hyp.11359
Volume 31
Issue 24
Year Published 2017
Language English
Publisher Wiley
Contributing office(s) Southwest Biological Science Center
Description 10 p.
First page 4328
Last page 4337
Country Mexico, United States
Other Geospatial Colorado River
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