Search

Groundwater depletion threatens global freshwater resources, necessitating urgent water management and policies to meet current and future needs. However, existing data-intensive approaches to assessments do not fully account for the complex human, climate, and water interactions within transboundary groundwater systems. Here, we present the design of and findings from a pilot participatory modeling workshop aiming to advance understanding of the hydrologic–human–climate feedback loops underpinning groundwater systems. Using participatory modeling tools and methods from the system dynamics tradition, we captured the mental models of researchers from water, social, data, and systems sciences. A total of 54 feedback loops were identified, demonstrating the potential of this methodology to adequately capture the complexity of groundwater systems. Based on the workshop outcomes, as an illustrative example, we discuss the value of participatory system modeling as a conceptualization tool, bridging perspectives across disciplinary silos. We further discuss how outcomes may inform future research on existing knowledge gaps around groundwater issues, and in doing so, advance interdisciplinary, use-inspired research for water decision-making more broadly. [ABSTRACT FROM AUTHOR]

Storage and release functions of western U.S. traditional river valley irrigation systems may counteract early and rapid spring river runoff associated with climate variation. Along the Rio Grande in northern New Mexico, we instrumented a 20-km-long irrigated valley to measure water balance components from 2005 to 2007. Hydrologic processes of the system were incorporated into a system dynamics model to test scenarios of changed water use. Of river water diverted into an earthen irrigation canal system, some was consumed by crop evapotranspiration (7.4%), the rest returned to the fiver as surface return flow (59.3%) and shallow groundwater return flow that originated as seepage from canals (12.1%) and fields (21.2%). The modeled simulations showed that the coupled surface water irrigation system and shallow aquifer act together to store water underground and then release it to the river, effectively retransmitting river flow until later in the year. Water use conversion to nonirrigation purposes and reduced seepage from canals and fields will likely result in higher spring runoff and lower fall and winter river flow. DOI: 10.1061/(ASCE)IR.1943-4774.0000265 CE Database subject headings: Aquifers; Hydrologic models; Hydrogeology; Irrigation systems; Surface water; Groundwater; Groundwater recharge; Rio Grande. Author keywords: River-aquifer interaction; Hydrology; Hydrologic models; Hydrogeology; Irrigation systems; Surface water; Groundwater; Groundwater recharge; Rio Grande.

In New Mexico in the arid southwestern United States, groundwater recharge is crucial to sustain groundwater (GW), which is vitally important to life, agriculture, industry, and ecosystems. To better understand the changes in recharge statewide, we explored the changes in groundwater recharge (RE), precipitation (P), surface water inflow (SWin), outflow (SWout), diversions (SWdiv), returns (SWret), and surface water and GW evapotranspiration (SWE and GWET) in five New Mexico counties: Taos, Torrance, Doña Ana, Eddy, and Lea during 1975-2015. The results show that the change-point of RE was in the 1990s, leading to contrasting tendencies in RE before and after the change-point with a decreasing rate during the latter one. There was a significant positive relationship between RE and P for Taos. The highest contribution rate (CR) to RE was SWout for Taos, whereas GWET ranked as the top CR for the other counties. Furthermore, the annual CR of GWET to RE increased significantly in all counties except Lea. The above results reveal that P and surface water flows played the dominant role in impacting RE in northern New Mexico where surface water is the primary local water resources, whereas GWET had the highest and increasingly continuous influence in central and southern New Mexico where the surface water is much less than that in northern New Mexico. This study shows that water budgets are important to identify differences in regional hydrological regimes that affect planning to maintain RE to groundwater. [ABSTRACT FROM AUTHOR]

Better understanding of surface water (SW) and groundwater (GW) interactions and water balances has become indispensable for water management decisions. This study sought to characterize SW-GW interactions in three crop fields located in three different irrigated valleys in northern New Mexico by (1) estimating deep percolation (DP) below the root zone in flood-irrigated crop fields; and (2) characterizing shallow aquifer response to inputs from DP associated with irrigation. Detailed measurements of irrigation water application, soil water content fluctuations, crop field runoff, and weather data were used in the water budget calculations for each field. Shallow wells were used to monitor groundwater level response to DP inputs. The amount of DP was positively and significantly related to the total amount of irrigation water applied for the Rio Hondo and Alcalde sites, but not for the El Rito site. The average irrigation event DP using data for the complete irrigation season at each of the three sites was 77.0 mm at El Rito, 54.5 mm at Alcalde and 53.1 mm at Rio Hondo. Groundwater level rise compared to pre-irrigation event water levels ranged from 3 to 1870 mm, and was influenced by differences in irrigation practices between sites. Crop evapotranspiration estimates averaged across irrigation events were highest in Rio Hondo (22.9 mm), followed by El Rito (14.4 mm) and Alcalde (10.4 mm). Results from this study indicate there are strong surface water-groundwater connections in traditionally irrigated systems of northern New Mexico, connections that may be employed to better manage groundwater recharge and river flow. [ABSTRACT FROM AUTHOR]

Ecological challenges in western forests continue to place a significant burden on land management practitioners. Increased tree densities since European settlement is arguably the greatest ecological challenge faced by land [...]

Traditional cultures in arid landscapes of the southwestern United States and northern Mexico developed irrigation systems to irrigate floodplain valleys along streams and rivers. Many of these traditional irrigation systems, referred to as acequias, continue to be used today. Population growth in the region is creating pressures to convert agricultural land and irrigation water to urban and other uses. Unique hydrologic features of the acequia systems suggest that, beyond providing crop irrigation, they may provide additional valuable hydrologic, riparian, and agroecosystem functions worth maintaining. We investigated in detail the seepage and the groundwater response to seepage from a traditional acequia irrigation ditch along the Rio Grande in north-central New Mexico. We found that 16% of ditch flow seeps into the ditch bed and banks. Groundwater levels near the ditch and midway between the ditch and the river rise 1 m or more within three to four weeks following the start of the irrigation season. The elevated groundwater table produced by ditch and field seepage is sustained until late summer when groundwater levels again drop. The seepage that provides this annual groundwater recharge also sustains riparian vegetation along the main ditch and side ditches. In light of our hydrologic analysis, we considered seepage-supported riparian areas and their ecological functions including aquatic habitat, terrestrial habitat, and water quality effects. Ace quia hydrology plays an important role in contributing to an ecologically healthy, agriculturally productive, and community-sustaining floodplain agroecosystem. [ABSTRACT FROM AUTHOR]

Drylands are susceptible to erosion by wind and water. Thus, the reestablishment of vegetation is a crucial focus of watershed restoration in order to stabilize soils and improve water infiltration. Currently, limited research exists quantifying vegetation responses to rock detention structures (RDS) in the Chihuahuan Desert, and no studies have quantified the effects of RDS paired with seed introduction. Our study area in the Rincon Arroyo Watershed, in southern New Mexico, tested the hypotheses that two types of RDS, micro‐catchments and stone‐lines paired with seeding, support increases in seedling recruitment and vegetation cover compared to untreated controls. This study also tested whether the application of seed to RDS alters plant communities in comparison to controls. One season after seeded RDS were applied, seedling recruitment, cover, and plant community responses were evaluated at treatment and control areas. Seeded stone‐lines showed significantly greater seedling recruitment (2×) and cover (0.3×) than controls (p < 0.05), whereas seeded micro‐catchments showed significantly greater cover (0.3×) than controls (p < 0.05) but did not exhibit significant differences in seedling recruitment compared to controls (p > 0.05). The lack of a significant difference between plant communities at treatment and control areas (p > 0.05) suggests that the addition of seed had little to no effect on plant communities or positive responses in seedling recruitment and cover. These results suggest that stone‐lines and micro‐catchments, alone, can support vegetation establishment in degraded dryland watersheds without the addition of seed. [ABSTRACT FROM AUTHOR]

Many agropastoral systems worldwide are supported by important linkages between crop production and rangeland grazing. We explored the connections between smallholder farming and public rangeland grazing in northern New Mexico, USA. We retrieved historical data of livestock inventories, drought, and hay production which we analyzed using either ordinary least squares models, generalized autoregressive conditional heteroscedasticity models (GARCH), or exponential GARCH models. We also conducted a survey of farmers and ranchers (n = 74) of traditional communities in our study area using a mixed methods design. County hay production was the only predictor that explained year-to-year variation in allotment livestock numbers. Allotments that increased livestock numbers tended to have larger base properties (mostly irrigated cropland). Most survey respondents (95%) raised livestock and slightly more than half agreed that livestock provided better financial security than crops. Availability of summer grazing lands and ability to grow or purchase hay to feed livestock during winter were the factors cited least (6% of responses) and most (42%), respectively, as limiting farmers’ ability to increase their herd size. Livestock-raising apparently continues to be critical to the acequia agropastoral economy. Ability to acquire winter feed (hay) appears to regulate the demand for summer grazing on public forested rangelands. [ABSTRACT FROM AUTHOR]