News Release, Kansas Geological Survey, December 19, 2019
LAWRENCE — A Kansas Geological Survey scientist shared his insight about groundwater recharge and flow as an invited speaker last summer on a National Academies of Sciences, Engineering, and Medicine workshop panel in Washington D.C. A report from the workshop was released this week.
Jim Butler, KGS senior scientist and geohydrologist, spoke on a panel focused on innovative ways to characterize aquifers and determine their long-term viability. The KGS is at the forefront of groundwater research because a large swath of western and central Kansas depends almost solely on groundwater for irrigation, industry, and municipal water supplies.
Much of the groundwater pumped in Kansas comes out of the High Plains aquifer, a massive network of underground water-bearing rocks that also extends into seven other states. It encompasses the Kansas portion of the Ogallala aquifer - by far the largest component of the High Plains aquifer - the Equus Beds near Wichita, and the Great Bend Prairie aquifer in south-central Kansas. The Ogallala aquifer, in particular, has experienced significant groundwater level declines since the 1950s due to increased usage, and its longevity is one of the most pressing environmental and economic concerns in the state.
"In western Kansas, the goal is to extend the lifespan of irrigated agriculture, which can only be accomplished if pumping is reduced," Butler said. "Implementation of pumping reductions, however, is uncharted territory in many parts of the aquifer. Thus, it is imperative that KGS researchers provide solid evidence and practically feasible solutions to give the irrigation community the confidence to move forward."
To get an accurate picture of conditions in different parts of the aquifer, scientists need to know not only how much water is being pumped out but how much change is occurring due to natural processes such as inflow from and outflow to other parts of the aquifer, interaction with surface water, recharge from precipitation, and transpiration.
Butler and his colleagues have developed an innovative approach for calculating what he calls "net inflow" - a grouping of all the natural inflows and outflows - from data collected in the field by the KGS and others. Reliable estimates of net inflow are critical for understanding the impact of pumping reductions.
"The key is the quality and quantity of data we have in Kansas regarding our groundwater resources," Butler said. "We are very fortunate that my predecessors in the water resources community understood that management of our aquifers requires data. They understood that you can't manage what you don't know."
Kansas is widely viewed as being a global leader in terms of data on groundwater resources. Pumping data, which are rarely available elsewhere, are readily available from the state because more than 95% of the high capacity pumping wells in the Kansas portion of the High Plains are metered. The measurements are reported to the state annually and subject to regulatory verification.
"The aim of my colleagues and I is to create methods and models that can be used to accurately estimate the status of our aquifers and their future prospects," Butler said. "Based on methods we developed, we can now confidently make short-term (years to a decade or two) predictions about the response of the High Plains aquifer in Kansas to changes in management strategies and climatic stresses. We feel that this is a major step forward."
Estimating groundwater volume change using various remote sensing approaches was another approach discussed by the workshop panel. The KGS method also could be used in conjunction with remote sensing methods to greatly extend the applicability of the method, Butler said.
The workshop was convened by the National Academies' Science and Technology Board to help identify scientific research frontiers that can advance monitoring and modeling of groundwater quantity, recharge, flow, and depletion around the world. Groundwater resources make up about 30% of freshwater on Earth and are the source of drinking water for half the planet's population.
The National Academies of Sciences, Engineering, and Medicine are private, nonprofit institutions that provide expert advice about policies, inform public opinion, and advance the pursuit of science, engineering, and medicine.
The KGS is a research and service division of the University of Kansas that studies and provides information on the state's geologic resources and hazards, including groundwater, oil and natural gas, rocks and minerals, and earthquakes. Its main headquarters is in KU’s West District in Lawrence, and its Wichita office houses the KGS Well Sample Library.
The workshop report, "Groundwater Recharge and Flow: Approaches and Challenges for Monitoring and Modeling Using Remotely Sensed Data," can be accessed at https://bit.ly/34BugXa.
A YouTube video of Butler's presentation is available at https://bit.ly/2MnTBhl.
Contact: Cathy Evans, (785) 864-2195.
Kansas Geological Survey, Public Outreach
URL="http://www.kgs.ku.edu/General/News/2019/butler_nas.html"