UC Davis
Senior Researcher

    UC Water Grant 2016
    Use of Unmanned Aerial Vehicles for Improving Land and Consumptive Use INformation in the Sacramento San Joaquin Delta

    The Sacramento-San Joaquin Delta (SSJD), the hub of the California intertied water supply system hosts urbanized areas, agriculture and a fragile ecosystem. Balancing water supply, salinity control and ecosystem services in the Delta merits careful accounting of water resources supply and demand. In average, about 6 million acre-feet per of water (maf) are exported out of the Delta annually. Agriculture in the Delta uses about 1.3 maf over 400 thousand acres of irrigated land.

    Accounting for consumptive use (water not returned to the system), allows better water management and understanding of the potential effects of some actions over the water balance and water quality in the region. This project builds current research for calculating consumptive water use in the SSJD via estimation of evapotranspiration (ET) in irrigated farming.

    The project Crop Consumptive Use Estimation in the Sacramento-San Joaquin Delta commissioned to the Center for Watershed Sciences by the California Waterboards, compares various methods to estimate consumptive use in the SSJD, with special emphasis in remote sensing-based methods that employ Landsat and other satellite multi-spectral imagery and ground level meteorological data to estimate ET through energy balance. This project proposes enhancing remote sensing based estimates through the use of higher resolution multi-spectral imagery in unmanned aerial vehicles (UAV). The approach allows quantification of uncertainties from lower resolution Landsat images, cloud cover and masking and other issues. Selected locations in the Delta will employ UAV imagery to respond to these questions and will help improving ET estimate in the SSJD.

    Research Interests

    • Large scale hydro-economic modeling for water management and policy analysis
    • Economics of groundwater management in water supply systems
    • Agricultural and urban water use adaptation to climate change and drought
    • Consumptive water use in agriculture using remote sensing
    • Impact analysis using partial and general equilibrium models
    • Data management and documentation systems
    UC Water Connection: 

    Dr. Medellín-Azuara has been involved with UC Water since its inception, has authored important California drought reports, and received a 2016 UC Water match grant for work on evapotranspiration on agricultural fields. 


    Josué Medellín-Azuara is a Senior Researcher at the Center for Watershed Sciences. He is an expert in the development of hydro-economic models with emphasis in agricultural production and water use. Some of his areas of interest include economics of water resources, consumptive water use using remote sensing, groundwater management, and large-scale modeling. Josué has experience working for industry and as a consultant and collaborator for government agencies, NGOs, industry and academia including the Natural Heritage Institute, the Stockholm Environment Institute, The World Bank, El Colegio de Mexico, the Catholic University of Chile, and the Universidad Federal de Rio Grande do Sul. Josué holds degrees in engineering, business and economics. He obtained his Ph.D. in Ecology from UC Davis in 2006 with his dissertation on hydro-economic analysis of environmental flows for the Colorado River Delta in Mexico.