HR: 0800h
AN: H41D-0426    [Abstracts]
TI: Mapping of Restoration-Induced Changes in Riparian Evapotranspiration
AU: * Loheide, S P
EM: sloheide@stanford.edu
AF: Geological and Environmental Sciences, Braun Hall Stanford University, Stanford, CA 94305 United States
AU: Gorelick, S M
EM: gorelick@pangea.stanford.edu
AF: Geological and Environmental Sciences, Braun Hall Stanford University, Stanford, CA 94305 United States
AB: Land-use practices such as logging and grazing have caused environmental degradation of riparian meadows in the Northern Sierra Nevada, CA, USA that has resulted in a succession from wet meadow vegetation to sagebrush and dryland grasses. In the past decade, restoration initiatives have sought to reverse these trends. These changes in vegetation cover impact the hydrologic cycle in ways that are important to understand for water resource management. In order to quantify the effect of riparian restoration on the evapotranspiration (ET) component of the hydrologic cycle, an ET Mapping Algorithm (ETMA) was recently developed. ETMA uses local weather station data and airborne thermal imagery collected with a forward-looking infrared (FLIR) camera to estimate ET at a 1-m resolution. The results of ETMA showed that daily ET in the restored meadows ranged from 5 to 6.5 mm/day whereas that of the degraded meadows was 1.5 to 4 mm/day. In addition, the detailed maps reveal spatial patterns in ET that have implications for land use practices; three examples will be discussed. First, land use practices such as grazing are observed to result in ET differences across fence lines. Second, the succession from wet meadow species to sagebrush and dryland grasses, which is often referred to as sagebrush encroachment, begins near incised channels and spreads towards the margins of the meadows. Third, restoration is seen to be very successful in the upper and middle portions of a restored stream reach; however, in the lower portion of a restored reach water availability appears to limit plant processes, which can be seen by the reduced ET. The application of ETMA has not only been useful in quantifying the changes in ET associated with riparian restoration, but has also elucidated the processes ultimately responsible for these changes in vegetation cover.
DE: 1813 Eco-hydrology
DE: 1818 Evapotranspiration
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1852 Plant uptake
DE: 1855 Remote sensing (1640)
SC: Hydrology [H]
MN: Fall Meeting 2005