Recently Funded (104g) Research Projects

FY 2025

Medium (30-meter) Resolution Evapotranspiration Modeling of the Quantity of Water Used for Alfalfa and Other Hay in the Lower Colorado River Basin
Russell Tronstad
 
This project aims to accurately quantify and map Lower Colorado River Basin water use of alfalfa and other hay crops at 30-meter resolution and at daily to weekly frequencies, where water shortages are a serious concern. Alfalfa and other hay crops made up 41% of Arizona’s crop portfolio in 2024. Landsat 8 and Sentinel-2 satellite images will be combined to get frequent and detailed estimations of a field’s water consumption or evapotranspiration. The measurements will be matched with ground-level data taken from field research stations near Maricopa and Yuma, Arizona, and Holtville, California, where flux towers measure the actual water lost to evaporation and transpiration. Our ultimate goal is to help farmers, policymakers, and water districts precisely identify where and when large quantities of water are being consumed by agriculture in the Lower Colorado River Basin. Quantifying this ET information will enable better-informed decisions about managing and conserving both ground and surface water resources.

FY 2023

Developing the Next Generation of U.S. Water Accounts: A Water Tower Methodology for Natural Capital Accounting
Benjamin Ruddell, Eric Sjöstedt, Ken Bagstad, Pierre Glynn

This project aims to produce a new methodology for national SEEA water accounting through development of a novel national water towers model that links water use to its origin in upstream headwater ecosystems. The researchers will examine basinscale fresh water and groundwater flows, stocks, inter-basin transfers, and water use Developing the Next Generation of U.S. Water Accounts 2 vulnerability. This project will produce (1) a spatially disaggregated USGS-derived water use dataset covering CONUS, (2) a CONUS, 800-meter map of water supply from U.S. water towers, and (3) high-resolution SEEA water accounts with sectoral and land cover-based accounts linking water supply and use that highlight socioeconomic vulnerabilities related to the Nation’s water supply. This proposed research will foster significant collaboration between USGS and University researchers. Overall, this research will develop new SEEA water accounting methods that provide essential insights for decision-making and policy for water resource management aiming at more sustainable watershed management in the era of climate change

FY 2020

In-stream contaminant attenuation by sunlight: benefits for water reuse
David Quanrud

Our project aimed to see how sunlight breaks down harmful substances in treated wastewater after it enters streams. We studied a 16-mile stretch of the lower Santa Cruz River near Tucson, Arizona, both in the field and the lab. We examined water samples and tested how sunlight affects certain contaminants. Then, we created a math model to design water recycling systems that use sunlight. We did seven field studies, two with USGS partners. They tracked how water flowed in the river. Out of sixteen contaminants, seven dropped in concentration by up to 95%. Lab tests showed that sunlight was the main factor in this reduction. We built a model that accurately predicts how contaminants are removed in streams. The project had several benefits. It gave research opportunities to twelve students, including five M.S. and three Ph.D. students. Also, it led to seven conference presentations by students. Additionally, two students spoke in seminars. Five media articles were published and six research publications are underway.  The lead project investigator was interviewed on TV.  Finally, we secured a new grant to continue the work.