Geology topics

Diane E. Boyer

Publications and source records attributed to Diane E. Boyer.

9 recordsLinked to original sources

USGS2011

Unravelling long-term vegetation change patterns in a binational watershed using multitemporal land cover data and historical photography

A significant amount of research conducted in the Sonoran Desert of North America has documented, both anecdotally and empirically, major vegetation changes over the past century due to human land use activities. However, many studies lack coincidental landscape-scale data characterizing the spatial and temporal manifestation of these changes. Vegetation changes in a binational (USA and Mexico) watershed were documented using a series of four land cover maps (1979-2009) derived from multispectral satellite imagery. Cover changes are compared to georeferenced, repeat oblique photographs dating from the late 19 th century to present. Results indicate the expansion of grassland over the past 20 years following nearly a century of decline. Historical repeat photography documents early-mid 20 th century mesquite invasions, but recent land cover data and rephotography demonstrate declines in xeroriparian/riparian mesquite communities in recent decades. These vegetation changes are variable over the landscape and influenced by topography and land management.

Arizona, California↗

USGS2011

Unravelling long-term vegetation change patterns in a binational watershed using multitemporal land cover data and historical photography

A significant amount of research conducted in the Sonoran Desert of North America has documented, both anecdotally and empirically, major vegetation changes over the past century due to human land use activities. However, many studies lack coincidental landscape-scale data characterizing the spatial and temporal manifestation of these changes. Vegetation changes in a binational (USA and Mexico) watershed were documented using a series of four land cover maps (1979-2009) derived from multispectral satellite imagery. Cover changes are compared to georeferenced, repeat oblique photographs dating from the late 19th century to present. Results indicate the expansion of grassland over the past 20 years following nearly a century of decline. Historical repeat photography documents early-mid 20th century mesquite invasions, but recent land cover data and rephotography demonstrate declines in xeroriparian/riparian mesquite communities in recent decades. These vegetation changes are variable over the landscape and influenced by topography and land management.

Conference Paper↗

USGS2008

Debris flows and floods in southeastern Arizona from extreme precipitation in July 2006 — Magnitude, frequency, and sediment delivery

From July 31 to August 1, 2006, an unusual set of atmospheric conditions aligned to produce record floods and an unprecedented number of slope failures and debris flows in southeastern Arizona. During the week leading up to the event, an upper-level low-pressure system centered over New Mexico generated widespread and locally heavy rainfall in southeastern Arizona, culminating in a series of strong, mesoscale convective systems that affected the region in the early morning hours of July 31 and August 1. Rainfall from July 27 through 30 provided sufficient antecedent moisture that the storms of July 31 through August 1 resulted in record streamflow flooding in northeastern Pima County and eastern Pinal County. The rainfall caused at least 623 slope failures in four mountain ranges, including more than 30 near Bowie Mountain in the northern Chiracahua Mountains, and 113 at the southern end of the Huachuca Mountains within and adjacent to Coronado National Memorial. In the Santa Catalina Mountains north of Tucson, 435 slope failures spawned debris flows on July 31 that, together with flood runoff, damaged structures and roads, affecting infrastructure within Tucson’s urban boundary. Heavy, localized rainfall in the Galiuro Mountains on August 1, 2006, resulted in at least 45 slope failures and an unknown number of debris flows in Aravaipa Canyon. In the southern Santa Catalina Mountains, the maximum 3-day precipitation measured at a climate station for July 29-31 was 12.04 in., which has a 1,200-year recurrence interval. Other rainfall totals from late July to August 1 in southeastern Arizona also exceeded 1,000-year recurrence intervals. The storms produced floods of record along six watercourses, and these floods had recurrence intervals of 100-500 years. Repeat photography suggests that the spate of slope failures was historically unprecedented, and geologic mapping and cosmogenic dating of ancient debris-flow deposits indicate that debris flows reaching alluvial fans in the Tucson basin are extremely rare events. Although recent watershed changes—particularly the impacts of recent wildland fires—may be important locally, the record number of slope failures and debris flows were related predominantly to extreme precipitation, not other factors such as fire history. The large number of slope failures and debris flows in an area with few such occurrences historically underscores the rarity of this type of meteorological event in southeastern Arizona. Most slope failures appeared to be shallow-seated slope failures of colluvium on steep slopes that caused deep scour of chutes and substantial aggradation of channels downstream. In the southern Santa Catalina Mountains, we estimate that 1.5 million tons of sediment were released from slope failures into the channels of ten drainage basins. Thirty-six percent of this sediment (527,000 tons) is gravel-sized or smaller and is likely to be transported by streamflow out of the mountain drainages and into the drainage network of metropolitan Tucson. This sediment poses a potential flood hazard by reducing conveyance in fixed-section flood control structures along Rillito Creek and its major tributaries, although our estimates suggest that deposition may be small if it is distributed widely along the channel, which is expected. Using the stochastic debris-flow model LAHARZ, we simulated debris-flow transport from slope failures to the apices of alluvial fans flanking the southern Santa Catalina Mountains. Despite considerable uncertainty in applying coefficients developed from worldwide observations to conditions in the southern Santa Catalina Mountains, we predicted the approximate area of depositional zones for several 2006 debris flows, particularly for Soldier Canyon. Better results could be achieved in some canyons if sediment budgets could be developed to account for alternating transport and deposition zones in channels with abrupt expansions and contractions, such as Rattlesnake Canyon.

Arizona↗

USGS2007

Channel response to low-elevation desert fire: The King Valley Fire of 2005

In late September to early October 2005, a fire swept north from the Yuma Proving Grounds and into the Kofa National Wildlife Refuge (NWR), traveling mainly along desert wash systems and low-relief alluvial fans. This fire burned 9,975 ha, moving through xeroriparian systems in washes as well as low-elevation desert ecosystems in King Valley, a major area of designated wilderness in the southern part of the Kofa NWR. Using satellite imagery, we determined that 9,255 ha of the Kofa NWR in King Valley burned. The fine-fuel loading for the fire was mostly a native forb (Plantago insularis), and the desert environment that was burned was mostly low-cover creosote bush (Larrea tridentata) scrub with scattered palo verde (Cercidium microphyllum). The wash environments had significant tree cover, including ironwood (Olneya tesota), blue palo verde (Cercidium floridum), desert willow (Chilopsis linearis), and/or smoke tree (Psorothamnus spinosa). This report presents monitoring data collected in June 2006 and January-February 2007 on the effects of this fire on channel morphology in King Valley.

Arizona↗

USGS2007

The Desert Laboratory Repeat Photography Collection - An Invaluable Archive Documenting Landscape Change

The Desert Laboratory Repeat Photography Collection, the largest collection of its kind in the world, is housed at the U.S. Geological Survey (USGS) in Tucson, Arizona. The collection preserves thousands of photos taken precisely in the same places but at different times. This archive of 'repeat photographs' documents changes in the desert landscape and vegetation of the American Southwest, and also includes images from northwestern Mexico and Kenya. These images are an invaluable asset to help understand the effects of climate variation and land-use practices on arid and semiarid environments.

Fact Sheet↗

USGS2003

Perennial vegetation data from permanent plots on the Nevada Test Site, Nye County, Nevada

Perennial vegetation data from 68 permanent plots on the Nevada Test Site, Nye County, Nevada, are given for the period of 1963 through 2002. Dr. Janice C. Beatley established the plots in 1962 and then remeasured them periodically from 1963 through 1975. We remeasured 67 of these plots between 2000 and 2003; the remaining plot was destroyed at some time between 1975 and 1993. The plots ranged from 935 to 2,274 m in elevation and are representative of common plant associations of the Mojave Desert, the transition to Great Basin Desert, and pinyon-juniper woodlands. The purpose of this report is to describe the complete set of ecological data that Beatley collected from the Nevada Test Site from 1963 through 1975 and to present the data for perennial vegetation collected from 2000 through 2003.

Open-File Report↗

USGS2001

Changes in riparian vegetation in the southwestern United States: Historical changes along the Mojave River, California

The alluvial aquifer of the Mojave River is the primary source of water for domestic supplies and irrigation in the western Mojave Desert. The river also supports riparian communities unique to the Mojave Desert ecosystem. North of the front of the Transverse Ranges, perennial flow extends reliably past Lower Narrows and extends past Helendale only during periods of storm runoff. Ground water supplies both domestic and irrigation to water users in the basin, particularly upstream from Upper Narrows and to a lesser extent between Barstow and Camp Cady. A model of the ground-water flow system, recently completed by Stamos and others (2001), confirms that ground-water levels in the basin have been declining steadily in the latter part of the 20th century as previously known from water-level measurements. Ground-water changes are of concern to land management agencies because they have led to decimation or elimination of riparian vegetation in some reaches (Lines, 1999). Some water is imported into the basin to artificially recharge the alluvial aquifer; this water also benefits riparian ecosystems. The purpose of this poster is to present initial findings on long-term changes in riparian vegetation along the Mojave River. Repeat photography documents long-term changes of riparian species along the Mojave River through the last 137 years. The first photographs of the Mojave River were taken by Richard D'Heureuse, a member of the California Geological Survey expedition of 1863, using a large-format, glass-plate camera. The expedition began in San Bernardino and travelled the Mojave Road from Victorville to the Colorado River. D'Heureuse photographed scenes that included the river and its attributes at Point of Rocks near present-day Helendale, at two sites near Barstow, at the old Camp Cady, at Afton Canyon, and at the site of present day Zzyzx on the west edge of Soda Lake playa. David Thompson, a hydrologist with the U.S. Geological Survey, worked on issues related to surface and ground water hydrology of the Mojave River in the 1910s and 1920s (Thompson, 1929). He photographed key reaches of the Mojave River, including the Upper and Lower Narrows near Victorville, the reach upstream of Helendale, Barstow, the Yermo area, and the reach between Camp Cady Ranch and Afton Canyon. Historical photography, which was black and white, documents only the larger-stature woody species. In the case of the Mojave River, these species are cottonwood ( Populus fremontii ), Goodding or black willow ( Salix gooddingii ), mesquite ( Prosopis glandulos a and minor amounts of P. pubescen s), and non-native tamarisk ( Tamarix ramosissima ). Smaller-stature species that appear in some of the photographs include coyote willow ( Salix exigua ) and seep willow ( Baccharis glutinosa ). As mapped by Lines and Bilhorn (1996), many other woody riparian species exist in the basin, mostly in small amounts. Some notable species include sycamore ( Platanus racemosa ), velvet ash ( Fraxinus velutina ), cattails ( Typha latifolia ), and bulrush ( Scirpus sp .). Invasive non-native species of note, other than tamarisk, include giant reed ( Arundo donax ), which was observed at Lower Narrows.

California↗

USGS2001

Changes in riparian vegetation in the southwestern United States : floods and riparian vegetation on the San Juan River, southeastern Utah

The San Juan River is an important source of water for agriculture and domestic use, is home to several endangered fish species, is a valued whitewater recreation area, and supports valued riparian habitat. This major tributary of the Colorado River drains 60,000 km2 (23,000 m²) of the Four Corners Region upstream from Mexican Hat, Utah, and has its headwaters in the San Juan Mountains of southwestern Colorado. The river cuts a course westward through northern New Mexico and southern Utah until it enters Lake Powell reservoir. The river was unregulated before June 28,1962, when Navajo Dam was completed; the dam's floodcontrol operations reduce peak discharges downstream. Before flow regulation, a very large flood occurred on the San Juan River on October 6, 1911, causing severe damage; however, the discharge for this flood has only been roughly estimated. Photographs of the river corridor from the 19th and early 20th centuries show a wide floodplain with sparse riparian vegetation, and repeat photographs show a large increase in both native and non-native vegetation. The purpose of this poster is to evaluate whether the 1911 flood, or other floods in the late 19th and early 20th century, explain the lack of riparian vegetation along this river, and whether flood control by Navajo Reservoir has resulted in an influx of riparian vegetation and channel narrowing.

Arizona, Colorado, New Mexico, Utah↗

USGS2001

Changes in riparian vegetation in the southwestern United States: Repeat photography at gaging stations

As part of the regular operation of surface-water gaging stations in Arizona, photographs are taken to document channel conditions. The photographs show many features of the channel that are important to accurate streamflow gaging, including shifts in channel thalwegs (the deepest point in the channel), changes in low-water controls, and changes in channel roughness. Photographs have been taken since gaging stations were first established in Arizona in the 1910s, and many photographs were taken in the 1920s and 1930s. Now, these photographs provide an invaluable record for evaluating changes in the riverine environment of the major water courses in Arizona. Riparian vegetation in particular is highly valued because of its biodiversity, wildlife habitat, and ability to favorably alter water quality. The long-term status of riparian ecosystems in the southwestern United States is much debated. Water development is frequently blamed for decimation or elimination of riparian ecosystems. Floods may damage or destroy vegetation within channels, and channel changes may cause damage to floodplain structures, agricultural fields, and water- and irrigation-supply systems. Increases in channel roughness may create higher stages during floods, raising the possibility of increased frequency of flood damage. The photography at gaging stations documents long-term changes in the riverine environments of Arizona. The images shown here are selected to illustrate the range of changes, which include large increases in native and non-native vegetation at most sites; complete elimination of riparian vegetation at some sites; and channel downcutting, lateral channel changes, and deposition of new fluvial terraces. The causes of many of the changes are not obvious. At some sites, riparian vegetation has increased despite the occurrence of large floods, flood control, or streamflow diversions. Despite the 20th century spread of tamarisk along the state's rivers, native species have increased as well. These photographs well illustrate the fact that Arizona's rivers have unstable channels and fast-changing riparian ecosystems, and management practices designed to protect Arizona's riparian ecosystems may benefit with this information.

Arizona↗