Analyses of meteorological and hydrological records support Tribal members’ accounts of changing climate on the Fort Apache Reservation, east–central Arizona

Jon P. Mason

doi:10.3133/sir20265140

Home/Archive/USGS

USGS · sir20265140

Analyses of meteorological and hydrological records support Tribal members’ accounts of changing climate on the Fort Apache Reservation, east–central Arizona

Jon P. Mason

View original source ↗Read source document ↗Export metadata ↓

Abstract

The Fort Apache Reservation in east–central Arizona, home to the White Mountain Apache Tribe of the Fort Apache Reservation, Arizona, contains several climate zones because of the large variation in surface elevation within the reservation. This study was carried out in cooperation with the White Mountain Apache Tribe of the Fort Apache Reservation, Arizona, to raise awareness of how the changing climate affects the Fort Apache Reservation. This report documents the evaluation of existing multidecadal meteorological and hydrological datasets for the Fort Apache Reservation, used to evaluate the effects of a changing climate on the reservation. In this evaluation, near-surface air temperature, snow depth, snow water equivalent, precipitation, and streamflow datasets were analyzed for monotonic trends indicative of changing climatic conditions during specified periods of time. The results of these trend analyses were then compared with the Tribal community's memories of the changing climate. Trend analysis of near-surface air temperatures from a U.S. Historical Climatological Network station on the Fort Apache Reservation at Whiteriver, Arizona, indicated that mean annual air temperatures have increased by an average of 2.48 degrees Fahrenheit from 1980 to 2023. Records from the same station also indicated that average monthly maximum temperatures recorded for March increased by 5.39 degrees Fahrenheit for the same time period. Annual precipitation at the five precipitation stations used in this study decreased greatly from the 1980s to 2023. The largest total decrease was 10.07 inches, or 34.7 percent. However, only one of the two precipitation stations with longer term data available prior to 1980 had a significant negative trend when data from the entire period of record, from 1901 to 2023, were analyzed. Trend analyses show a decrease in the annual maximum snow water equivalent and an earlier disappearance of the snowpack at two Natural Resources Conservation Service snow telemetry stations in the mountainous region just east of the Fort Apache Reservation from 1981 to 2023. Based on the trend analyses, the average annual maximum snow water equivalent has decreased by more than 40 percent at both stations, and the average date when the snowpack was fully melted at the stations in the spring has moved earlier in time from late April to early April or late March. However, a statistically significant trend was not determined for the early April snow water equivalent measured at a nearby Natural Resources Conservation Service snow course across its period of record, indicating that the history of mountain snowpack in this area is not fully understood. Analysis of snowfall data from a National Oceanic and Atmospheric Administration Cooperative Observer Program network station on the Fort Apache Reservation at McNary 2N, AZ (station 025412) indicated that, on average, the measured total annual snowfall at the station decreased 42.4 percent from 1935 to 2023. Streamflow data from six U.S. Geological Survey streamgages on the Fort Apache Reservation were analyzed for trends. For most streamflow gages, statistically significant trends were not determined for tested parameters when the entire streamflow period of record was used for stations with records going back to at least the 1960s. However, when the data from 1980 to 2023 was tested, most of the streamflow parameters had statistically significant negative trends. All six streamgages showed a decrease in average annual runoff of at least 50 percent from 1980 to 2023; one streamgage showed an 81.8 percent decrease. A similar statistical finding was observed in the analysis of the annual spring snowmelt peak from one of the six streamgages used in the study and located in an area receiving measurable amounts of snowmelt runoff. When data from the entire period of record (1958–2023) was used, no trend in streamflow was determined; however, a significant negative trend was determined from 1980 to 2023, indicating a decrease in average annual springtime runoff of 62.6 percent. Statistical analysis on the timing of the annual spring snowmelt peak at the same streamgage indicated the snowmelt peak is happening on average about 12 days earlier now (2023) than it did in the past. The trend results for the timing of the annual spring snowmelt peak were the same and statistically significant for both periods tested (1958–2023 and 1980–2023). Two of the streamflow records from the Fort Apache Reservation were compared to the Palmer Hydrological Drought Index computed for Arizona Climate Division 4 (East Central) by the National Centers for Environmental Information. The comparison showed that the streamflow records generally tracked the Palmer Hydrological Drought Index. In interviews, Tribal community members living on the Fort Apache Reservation described the changes in climate that they observed during their lifetimes. Common themes reported were that air temperatures have become warmer, and the weather is less predictable with changes in seasonal patterns. Drier conditions, lower snowfall, shorter winters, and lower river levels were also reported. These community member observations align with the results of this study.

Explore related subjects

Scientific Investigations Report Report

Source-reported bounding extent: 33.5° to 34.5° latitude; -110.75° to -109.45° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Jon P. Mason. 2026-04-15. Analyses of meteorological and hydrological records support Tribal members’ accounts of changing climate on the Fort Apache Reservation, east–central Arizona. https://doi.org/10.3133/sir20265140

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Baseline water-quality inventory and summary for the Paterson Great Falls National Historical Park, New Jersey

The Paterson Great Falls National Historical Park (PAGR), established in 2011 in the City of Paterson, New Jersey, contains many cultural, historical, and natural resources. Because of the PAGR’s young age and limited resources, a long record of natural resource data is not available for use to guide future park management and planning decisions. A detailed natural resource inventory was identified as an immediate need in the “Foundation Document—Paterson Great Falls National Historical Park,” given the history of extensive industrial activity throughout the PAGR and the Passaic River Basin. The U.S. Geological Survey, in cooperation with the National Park Service and the Urban Waters Federal Partnership for the Lower Passaic River, inventoried water-quality monitoring efforts and compiled historical water-quality data from secondary data sources to define baseline conditions in the PAGR and the surrounding study area. This report documents the methods used to harmonize water-quality data aggregated from multiple sources for the PAGR study area. Procedures implemented during data harmonization include compiling data from multiple sources, assessing the dataset for completeness, addressing metadata concerns, and creating a consistent and quality-assured dataset for future analysis. The harmonized dataset contains 14 aggregated surface-water sites, 1,103 individual sampling days, and 32,000 water-quality records throughout the period of record defined for this study (1952–2021). Summary statistics and comparison to water-quality criteria are provided for focus parameters that can support PAGR management, including field properties, suspended material, total dissolved solids, specific conductance, chloride, sulfate, Escherichia coli, nutrients, contaminants of concern related to fish consumption advisories, and litter and floatable debris. A spatial data gap was identified for the recreational area near the base of the Great Falls and immediately downstream from a known combined sewer overflow discharge location. Analytic data gaps were identified for continuous streamflow and water-quality parameters, floatable debris characterization, and harmful algal blooms identification. Continuous collection of contaminants of concern was identified as a temporal data gap, as these parameters were not consistently collected within the study area. The water-quality data synthesis and summary presented in this report can assist PAGR staff in understanding the complex baseline water resources within the study area and can serve as a baseline to design future water-quality monitoring efforts and evaluate changes in water quality over time. The harmonized dataset, as well as future New Jersey Department of Environmental Protection and New Jersey Harbor Discharge Group monitoring data and assessments, can also be used to examine the status and trends in surface-water quality, support compliance with the Clean Water Act (33 U.S.C. 1251 et seq.), and further investigate changes to park water resources that can affect ecological and human health.

New Jersey↗

USGS2026

Slip tendency and dilation tendency of Quaternary faults in the Great Basin region, Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming

This report presents the results of slip tendency and dilation tendency analysis of Quaternary faults in the Great Basin region, in the states of Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming. This effort was undertaken as part of two studies: the U.S. Department of Energy Geothermal Technologies Office-funded Innovative Geothermal Exploration through Novel Investigations of Undiscovered Systems (INGENIOUS) project, which is a multidisciplinary, multi-institution effort to develop new methodologies and best practices to accelerate the discovery of new, commercially viable hydrothermal resources; and the U.S. Geological Survey Geothermal Resources Investigations Project. The goal of this work is to identify faults and fault segments that are appropriately oriented to be stress-loaded for slip or to dilate under the ambient stress conditions. Both conditions may make such faults more likely to host permeability and fluid flow relative to other faults in the region. Slip tendency and dilation tendency were calculated for all fault segments in the study area from the U.S. Geological Survey Quaternary Fault and Fold Database. Results demonstrate that faults with high slip tendency and dilation tendency are common in the Great Basin region. The areas containing many high slip tendency and dilation tendency fault segments are associated with high strain rates. These areas also host a relatively high proportion of the known hydrothermal systems. This indicates that faults with high slip tendency and dilation tendency in areas with high strain-rate are potentially most prospective for hosting hydrothermal systems. The database published in coordination with this report contains the slip tendency and dilation tendency results data, including the fault geometry and stress data used to calculate these quantities, for both the Great Basin study area and the smaller INGENIOUS study area.

Arizona, California, Idaho, Nevada, Oregon, Utah, ↗

USGS2026

A spatial analysis of the groundwater emergence flood hazard in Long Island, New York, and coastal areas surrounding Long Island Sound in New York, Connecticut, and Rhode Island

Long Island, New York, and nearby coastal areas surrounding Long Island Sound are densely populated and, like other coastal areas, are susceptible to flooding from several potential sources, including stormwater from precipitation events, tidal flooding and storm surge, and groundwater emergence flooding. Groundwater emergence fooding refers to the intersection of a rising water table with land surface or critical infrastructure. Many studies of flood drivers either neglect or only briefly discuss how shallow groundwater conditions may contribute to or exacerbate flood conditions. As a part of a comprehensive study of compound flood hazards in the coastal areas of Long Island and Long Island Sound, a spatial analysis was completed by the U.S. Geological Survey, in cooperation with the Environmental Protection Agency’s Long Island Sound Partnership, formerly called the Long Island Sound Study, using available regional datasets to characterize the potential hazard for groundwater emergence flooding. The approximately 3,100 square mile study area was subdivided into 11,407 grid cells that were 900 meters by 900 meters (approximately 3,000 feet by 3,000 feet), for the purpose of integrating the spatial datasets to calculate and map the groundwater emergence flood hazard. The depth to the water table, hydrologic soil groups, and National Land Cover Database were harmonized to the common grid. A groundwater emergence flood hazard score was calculated for each grid cell for current average conditions following a set of rules accounting for the depth to the water table and the percentage of area within each cell with slow infiltrating soils. A scenario with a higher sea-level position was also calculated for the Long Island part of the study area. The calculated groundwater emergence flood hazard score was reviewed in conjunction with the National Land Cover Database to identify developed areas and associated infrastructure that may be at risk of potential groundwater emergence flooding. Study results indicate that the groundwater emergence flood hazard is highest in coastal areas and near surface water where the water table is close to ground surface. Inland areas away from surface waterbodies are not likely to be exposed to groundwater emergence flooding. For Long Island, in the scenario with higher sea-level position, a greater groundwater emergence flood hazard is calculated for some locations closer to the coast and where land is submerged. Away from the coast and surface-water drainage, the groundwater emergence flood hazard is similar between the current average sea-level condition and the higher sea-level position scenario.

Connecticut, New York, Rhode Island↗