Climate model projections show that New Mexico’s future will be hotter and drier, with reduced water supplies from the Rio Grande, presenting serious challenges for policy makers and agricultural stakeholders. . A new study titled “Adapting irrigated agriculture in the Middle Rio Grande to a warm-dry future” analyzes the long-term tradeoffs of land and water management interventions that help irrigated agriculture adapt of the increasing scarcity of water in a desert environment.
David Gutzler, a professor in the Department of Earth & Planetary Sciences at The University of New Mexico (UNM), along with UNM students and collaborators at other regional universities led by the University of Texas-El Paso, investigated of the potential impacts of various intervention scenarios on agricultural water supplies in the Rio Grande Valley downstream of Elephant Butte Reservoir.
This research has a great impact on New Mexico because while this study focuses on hydrology and climate change, there is also a large area of water management related to interstate and international water sharing agreements. water. The research was conducted in collaboration with communities that share river water and groundwater in southern New Mexico, western Texas, and across the Mexican state border in Chihuahua.
The research analyzed 19 different intervention scenarios, including the implementation of deficit irrigation, changes in cropping patterns using existing crops, and the introduction of new alternatives that plant that does not tolerate drought and salt. The hydrological simulation was carried out using the soil and water assessment tool (SWAT) model, taking into account the limitations of the model in making the scenario simulation.
“We made a six-year effort with a large interdisciplinary team, including hydrologists, economists, and agricultural experts, to determine the future of water in the transboundary region along the Rio Grande, and think about potential ways that the community can adapt to. projected reductions in water supplies,” Gutzler said.
“A major part of the UNM-based research is making projections of future river flows into the Elephant Butte reservoir. We started with the US Bureau of Reclamation’s model of natural flow projections. river flow in a future climate warmed by the addition of greenhouse gases. But we can’t use natural flow projections directly.”
“The actual flow of the Rio Grande that comes to Elephant Butte is nowhere near natural because we withdraw so much water upstream, putting it to beneficial use in Colorado and northern New Mexico. flows coming into the reservoir into something more realistic, accounting for surface water withdrawals.”
Gutzler and UNM graduate student, Nolan Townsend, did this in a purely statistical way. They adjusted the average simulated historical time course by truncating the course by a fraction to match the corresponding long-term average of the observations. They applied historical adjustment statistics to future flows, effectively assuming that surface water management will not statistically change in the coming decades. They also keep the current (in 2020) management rules for releasing water from the reservoir unchanged.
This approach yields projections of how much water will be available from storage at Elephant Butte for irrigated agriculture and for the cities of El Paso and Juarez, and how much water will be available to sustain groundwater in the south. in Elephant Butte, assuming that the water management rules currently in effect have not changed.
Gutzler emphasized that there are many ways to change water management policies. The main result of this study shows that if the rules are not changed then water supplies will become completely unsustainable in a warm climate. Therefore, the study highlights the need to change water management rules to address the impending issues of water scarcity. As Gutzler said, “If we don’t change the rules, we’re going to run out of water there.”
However, the study identifies the complexities and challenges associated with implementing new water management strategies. Gutzler noted that political factors, historical treaties, and financial considerations will play an important role in shaping future water policies.
“However, we are at the point where water availability cannot reliably meet the demand for water under current management rules,” Gutzler said. “I think we can present that with confidence. There are many ways to change the water management system that may or may not solve the deficit.”
Gutzler explained that there are also alternative ways to generate water supply for the region, but he emphasized that some of these alternatives may not be realistic. He says that it is technically possible to build a pipe from the Mississippi River and bring water; But the questions arise as to who will pay for it, and are people in other places ok to send their water to the Southwest?
Another alternative to creating new water is desalination. However, this process can cause environmental problems such as what to do with the remaining brine. This process is also very expensive compared to the current water supplied by the river.
“One can also imagine new rules that will maintain certain levels of river flows for environmental purposes. And we can quantify that. production.”
Gutzler said there are different watering patterns that could be affected. He talked about how agricultural farmers change their crops from cotton or pecans to pistachios as an example and what the effect is on the overall water supply.
“The summary result is that there are strategies that farmers can use to reduce water consumption and still produce crops… There are many ways that farmers can choose to adapt and people who manage water allocations in our study region may choose to adapt by limiting supplies.”
The results suggest that irrigated agriculture in the Middle Rio Grande can be adapted to a warmer and drier future, but it will require a combination of changes in grower management, alternative crops, and more efficient irrigation technology. The study highlights the importance of long-term planning and collaboration among stakeholders to ensure sustainable water management in the region.
Gutzler concluded, “In academia, we’re in the business of evaluating options and saying, here’s what could happen, and here’s what’s likely to happen in terms of the future of water if you do option A and don’t do option A B. Our hope is that studies like ours will help inform policymakers about their best options in this discussion.”
The study sheds light on the urgent need to adapt irrigated agriculture in the Middle Rio Grande to a hot-dry future, highlighting the importance of proactive measures to address the challenges of water scarcity in the region. “Conflict about water supplies is not going away and I hope that exercises like ours help inform policymakers and water users about what their best options are,” added Gutzler.
The findings are published in Journal of Hydrology: Regional Studies.
Maryam Samimi et al, Adapting irrigated agriculture in the Middle Rio Grande to a hot dry future, Journal of Hydrology: Regional Studies (2022). DOI: 10.1016/j.ejrh.2022.101307
Provided by the University of New Mexico
Citation: Warmer temperatures, less water present challenges for policymakers, agriculture stakeholders (2023, July 19) retrieved 19 July 2023 from https://phys.org/news/2023- 07-hotter-temperatures-policy-makers-agricultural.html
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