Arizona's landmark Groundwater Management Act turned 40 last year and the WRRC marked the occasion by focusing the 2020 annual conference on the legacy of the Act, current groundwater challenges, and potential future pathways. Building on this foundation, the authors of the 2021 Arroyo developed a comprehensive overview of groundwater management in Arizona that looks back over 40 years and ahead toward 2060 and beyond. The presentation will highlight key sections of the Arroyo as reference points for discussion.

New Techniques for Mapping planted versus fallowed croplands using MODIS data
Cindy Wallace, Research Geographer, USGS Western Geographic Science Center

An important metric to monitor for optimizing water use in agricultural areas is the amount of cropland left fallowed, or unplanted. Fallowed croplands are difficult to model because they have many expressions; for example, they can be managed and remain free of vegetation or be abandoned and become weedy if the climate for that season permits. Western Geographic Science Center researchers used 250 m, 8-day composite Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data to develop an algorithm that can routinely map cropland status (planted or fallowed) with over 75% user’s and producer’s accuracies. The technique compares the current greenness of a cultivated pixel to its historical greenness and to the greenness of all cultivated pixels within a defined spatial neighborhood, and is therefore transportable across space and through time. The research is part of DOI’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) Program that is working to achieve a sustainable water strategy to meet the Nation’s water needs. Timely and accurate knowledge of the extent of fallowing can provide decision makers with insights and knowledge to mitigate the impacts of drought and provide a scientific basis for effective management response. The results are published in GIScience & Remote Sensing. Contact: Cynthia SA Wallace
Cynthia Wallace is a Research Geographer with the USGS Western Geographic Science Center who conducts interdisciplinary studies into areas of concern for natural resource management, such as invasive species, environmental change, water and food security, natural hazards and sustainability. Her research uses satellite imagery, spatial analysis and geographic information system (GIS) technologies to map natural phenomena and characterize the complex spatial and temporal variability of landscapes. She earned a PhD in Geography and Regional Development here at the University of Arizona, with a BS (Geology and Math) from the University of Minnesota- Duluth and an MS (Geology) from the University of Wisconsin - Madison.
Upcoming Events

Brown Bag Webinar: Arizona's Groundwater Management - Past, Present and Future

Brown Bag Webinar: Community Service and Environmental Justice as an Essential Best...
The old paradigm for clean water utilities was to see permit compliance as the ceiling of aspirations and to avoid community engagement to the maximal extent possible. However, the new paradigm for the clean water utilities of the future is to see permit compliance as a floor and to strive to be environmental champions and anchor institutions in the communities they serve.

World Water Day Special Webinar - Managing Aquifer Recharge: A Showcase for Resilience...
Celebrate World Water Day on Monday afternoon, March 22, when the Water Resources Research Center hosts an informative panel discussion on the forthcoming UNESCO volume, “Managing Aquifer Recharge: A Showcase for Resilience and Sustainability.”