Last updated: March 19, 2025
Article
Climate and Water Monitoring at Fort Davis National Historic Site: Water Year 2022
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Overview
Together, climate and hydrology shape ecosystems and the services they provide, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and surface water is key to assessing the condition of park natural resources—and often, cultural resources.
At Fort Davis National Historic Site (Figure 1), Chihuahuan Desert Network scientists study how ecosystems may be changing by taking measurements of key resources, or “vital signs,” year after year—much as a doctor keeps track of a patient’s vital signs. This long-term ecological monitoring provides early warning of potential problems, allowing managers to mitigate them before they become worse. At Fort Davis National Historic Site, we monitor climate and groundwater, among other vital signs.
Groundwater conditions are closely related to climate conditions. Because they are better understood together, we report on climate in conjunction with water resources. Reporting is by water year (WY), which begins in October of the previous calendar year and goes through September of the water year (e.g., WY2022 runs from October 2021 through September 2022).
This article reports the results of climate and groundwater monitoring at Fort Davis National Historic Site (Figure 1) in WY 2022.
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Climate and Weather
There is often confusion over the terms “weather” and “climate.” In short, weather describes instantaneous meteorological conditions (e.g., it’s currently raining or snowing, it’s a hot or frigid day). Climate reflects patterns of weather at a given place over longer periods of time (seasons to years). Climate is the primary driver of ecological processes on earth. Climate and weather information provide context for understanding the status or condition of other park resources.
Methods
A National Oceanic and Atmospheric Administration Cooperative Observer Program (NOAA COOP) weather station, (Fort Davis # 413262) has been operational at Fort Davis National Historic Site since 1902 (Figure 1). This station typically provides a reliable climate dataset. However, in WY2022 the station was missing data on 238 days. As a substitute, climate analyses in this report use 30-year averages (1991–2020) and gridded surface meteorological (GRIDMET) data from the location of the visitor center at the park. Subsequent reports may revert to the weather stations as the data source, depending on future data quality.
GRIDMET is a spatial climate dataset at a 4-km resolution that is interpolated using weather-station data, topography, and other observational and modeled land-surface data. Temperature and precipitation estimated from GRIDMET may vary from actual weather at a particular location, depending on the availability of weather-station data and the difference in elevation between the location of interest and that assigned to a grid cell. Data from both weather station(s) and GRIDMET are accessible through Climate Analyzer.
Results for Water Year 2022
Precipitation
Annual precipitation at Fort Davis National Historic Site in WY2022 was 15.13″ (38.4 cm; Figure 2), which was slightly less (0.31″, 0.8 cm) than the 1991–2020 annual average. Monthly precipitation totals from October through May were substantially less than the 1991–2020 averages. Rainfall totals in June and August were approximately double the monthly averages.
Air Temperature
The mean annual maximum temperature at Fort Davis National Historic Site in WY2022 was 77.8°F (25.5°C), 1.4°F (0.8°C) above the 1991–2020 average. The mean annual minimum temperature in WY2022 was 47.6°F (8.7°C), 1.5°F (0.8°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2022 differed by as much as 9.3°F (5.1°C; see December as an example) relative to the 1991–2020 monthly averages (Figure 2). Mean monthly minimum temperatures were warmer than 1991–2020 averages for the entire year, except January– March. Mean monthly maximum temperatures were more variable relative to 1991–2020 averages.
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Drought
Reconnaissance drought index (Tsakiris and Vangelis 2005) provides a measure of drought severity and extent relative to the long-term climate. It is based on the ratio of average precipitation to average potential evapotranspiration (the amount of water loss that would occur from evaporation and plant transpiration if the water supply was unlimited) over short periods of time (seasons to years). The reconnaissance drought index for Fort Davis National Historic Site indicates that WY2022 was slightly drier than the 1991–2022 average from the perspective of both precipitation and potential evapotranspiration (Figure 3).
Reference: Tsakiris G., and H. Vangelis. 2005. Establishing a drought index incorporating evapotranspiration. European Water 9: 3–11.
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Groundwater
Groundwater is one of the most critical natural resources of the American Southwest, providing drinking water, irrigating crops, and sustaining rivers, streams, and springs throughout the region.
Methods
Fort Davis National Historic Site groundwater is monitored using two wells near the park (Figure 1). Each well is monitored annually by the Texas Water Development Board (TWDB) and the data are available at the Texas Water Development Board Groundwater Database.
Recent Findings
Groundwater near Fort Davis National Historic Site was monitored by TWDB on 14 February 2022. Water levels in the two monitored wells decreased slightly between WY2020 and WY2022 (Figure 4 and Table 1). Water level in well 52-25-309 appears to be driven by precipitation and has varied by 11.36 ft (3.46 m) over the monitoring record (Figure 4). Groundwater at well 52-25-308 has been stable and shallow, varying only by 4.01 ft. This well does not appear to be strongly influenced by precipitation. Its proximity to Limpia Creek likely buffers well 52-25-308 from the larger water level fluctuations observed at well 52-25-309.
| TWDB Well Number | Location | Wellhead Elevation (ft amsl) |
Depth to Water (ft bgs) |
Water Level Elevation (ft amsl) |
Change in Elevation from WY2020 (± ft)* |
Change in Elevation from Earliest Recorded Water Level (± ft and year of first record) |
|---|---|---|---|---|---|---|
| 52-25-308 | 1,100 ft northeast of the park adjacent to Limpia Creek. | 4,827.00 | 12.16 | 4,814.84 | −0.46 | −1.76 (1967) |
| 52-25-309 | 144 ft east of the park | 4,860.00 | 34.18 | 4,825.82 | −1.05 | −6.08 (1967) |
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Report Citation
Article created by the Chihuahuan Desert Inventory and Monitoring Network.