Project Number: 5342-13610-010-00
Project Type: Appropriated

Start Date: Jan 31, 2007
End Date: Jan 29, 2012

Objective:
The existing project objectives (as given below) reflect the redirection towards quantification of climate change effects: 1. Develop methods and techniques for quantifying natural and anthropogenic induced ephemeral-channel runoff and subsequent recharge in cooperation with U.S. Geological Survey Tucson Science Center under current and projected climate scenarios. 2. Develop methods and techniques to quantify and predict water budgets of riparian ecosystems under current and projected climate scenarios through direct measurements of evaporation and plant transpiration and predict water savings by removal of invasive mesquite vegetation. 3. Develop methods and techniques to explicitly quantify the spatial and temporal distribution of vegetation, land use, and infiltration reduction using remotely sensed methods to improve prediction of basin scale semi-arid water budget components.

Approach:
Methods of investigation include field and laboratory experimentation, as well as the development and use of state-of-the-science watershed models and the use of remote sensing for watershed characterization. Satellite derived rainfall will be evaluated using raingages for large area rainfall estimation, the enhancement of recharge due to urbanization will be examined in adjacent, well instrumented, natural and residentially developed catchments. High-resolution remotely sensing and rainfall simulator experiments will be used to evaluate the capability to remote estimate infiltration rates on compacted and constructed surface common to development at the urban-rural interface. Remote spectral surface responses will be combined with energy balance models and radiative transfer theory to estimate surface water, carbon and energy fluxes based on observations from a network of five eddy-covariance and two Bowen ratio towers. A number of modeling components for the Automated Geospatial Watershed Assessment (AGWA) will be developed or enhanced to enable a more realistic representation of watershed processes and best management practices. AGWA will be migrated to both the internet and ARCGIS platforms to enhance usability and access. In addition we will quantify the physical mechanisms and component fluxes that are responsible for the observed ecosystem-scale water and CO2 fluxes. Scientists will carry out this research at sites located across both a riparian and an upland woody plant encroachment gradient. Continue existing research under objective #3, and add activities to develop methods and techniques to quantify and predict water budgets under current and projected climate scenarios through direct measurements of evaporation and plant transpiration, and predict water savings by removal of invasive mesquite vegetation.