UC Merced Magazine | Volume XIX, Issue V

Innovation and Persistence Helping Build a Climate-resilient Water Future

OPINION

By Joshua Viers, associate vice chancellor for interdisciplinary research and strategic initiatives An invisible water surcharge is quietly reshaping the landscape of agriculture in the San Joaquin Valley. Under the in uence of climate change, our warming planet is extracting more moisture from the soil and cultivated plants into the atmosphere. For this region — a global powerhouse in the production of fruits, nuts and vegetables — the increase in evapotranspiration elevates what is already an unprecedented challenge: California water demand exceeds supply in many places. In the San Joaquin Valley, an overreliance on depleting groundwater aquifers and highly variable surface water from runo and imports from other regions is prompting deep conversations about the sustainability of agriculture, which could not only impact the global fruit and nut supply, but also the economies of our local communities. California water management strategies have long been anchored around the concept of stationary hydrologic patterns. In other words, the past can

be used to guide the future. We now know that the dynamic nature of hydrologic processes, a challenge to manage historically, are being exacerbated by extreme variations in precipitation, now swinging from prolonged dry years to pronounced wet ones. Marked increases in evapotranspiration rates, diminished snowpack stores and increased variability in snowmelt runo are sparking reevaluation of water resource management strategies. Further, the San Joaquin Valley epitomizes the broader challenges faced by California. As the state implements its Sustainable Groundwater Management Act (SGMA), the region will need to reduce its demand broadly, resulting in a 10-20% reduction in cropped acreage. Scientists and engineers at UC Merced, through the Secure Water Future program, are tackling key components of this challenge to better inform and support decision-making about the equitable allocation and use of limited water resources. By enabling more precise measurements in crop evapotranspiration, soil moisture conditions and groundwater levels,

we can identify opportunities for changes in practice. In some cases, these changes include shi s to more drought tolerant crops and cropping patterns, in other cases it’s identifying the technologies and locations needed to actively manage aquifers through recharge. e team is also exploring the socioeconomic dimensions of water markets, which provide a mechanism for the voluntary reallocation of scarce water to other users and uses. Such markets can o er a exible strategy for users to manage sudden shi s in water availability during droughts. With proper design and execution, water markets can facilitate adaptation to increasingly variable supply. In all cases, better data, which is openly accessible and transparent, can promote better decision making across all sectors and users. UC Merced is helping our region build a more climate resilient water future through innovation in water measurement, management and markets. Joshua Viers is also a professor of civil and environmental engineering and the faculty program director for Secure Water Future.

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