1
|
Sankey JB, East A, Fairley HC, Caster J, Dierker J, Brennan E, Pilkington L, Bransky N, Kasprak A. Archaeological sites in Grand Canyon National Park along the Colorado River are eroding owing to six decades of Glen Canyon Dam operations. J Environ Manage 2023; 342:118036. [PMID: 37182479 DOI: 10.1016/j.jenvman.2023.118036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 05/16/2023]
Abstract
The archaeological record documenting human history in deserts is commonly concentrated along rivers in terraces or other landforms built by river sediment deposits. Today that record is at risk in many river valleys owing to human resource and infrastructure development activities, including the construction and operation of dams. We assessed the effects of the operations of Glen Canyon Dam - which, since its closure in 1963, has imposed drastic changes to flow, sediment supply and distribution, and riparian vegetation - on a population of 362 archaeological sites in the Colorado River corridor through Grand Canyon National Park, Arizona, USA. We leverage 50 years of evidence from aerial photographs and more than 30 years of field observations and measurements of archaeological-site topography and wind patterns to evaluate changes in the physical integrity of archaeological sites using two geomorphology-based site classification systems. We find that most archaeological sites are eroding; moreover, most are at increased risk of continuing to erode, due to six decades of operations of Glen Canyon Dam. Results show that the wind-driven (aeolian) supply of river-sourced sand, essential for covering archaeological sites and protecting them from erosion, has decreased for most sites since 1973 owing to effects of long-term dam operations on river sediment supply and riparian vegetation expansion on sandbars. Results show that the proportion of sites affected by erosion from gullies controlled by the local base-level of the Colorado River has increased since 2000. These changes to landscape processes affecting archaeological site integrity limit the ability of the National Park Service and Grand Canyon-affiliated Native American Tribes to achieve environmental management goals to maintain or improve site integrity in situ. We identify three environmental management opportunities that could be used to a greater extent to decrease the risk of erosion and increase the potential for in-situ preservation of archaeological sites. Environmental management opportunities are: 1) sediment-rich controlled river floods to increase the aeolian supply of river-sourced sand, 2) extended periods of low river flow to increase the aeolian supply of river-sourced sand, 3) the removal of riparian vegetation barriers to the aeolian transport of river-sourced sand.
Collapse
Affiliation(s)
- Joel B Sankey
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, AZ, USA.
| | - Amy East
- U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, USA
| | - Helen C Fairley
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, AZ, USA
| | - Joshua Caster
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, AZ, USA
| | - Jennifer Dierker
- U.S. National Park Service, Grand Canyon National Park, Flagstaff, AZ, USA
| | - Ellen Brennan
- U.S. National Park Service, Grand Canyon National Park, Flagstaff, AZ, USA
| | - Lonnie Pilkington
- U.S. National Park Service, Grand Canyon National Park, Flagstaff, AZ, USA
| | - Nathaniel Bransky
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, AZ, USA
| | - Alan Kasprak
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff, AZ, USA; Fort Lewis College, Geosciences Department and Four Corners Water Center, Durango, CO, USA
| |
Collapse
|
2
|
Li J, Ravi S, Wang G, Van Pelt RS, Gill TE, Sankey JB. Woody plant encroachment of grassland and the reversibility of shrub dominance: Erosion, fire, and feedback processes. Ecosphere 2022. [DOI: 10.1002/ecs2.3949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Junran Li
- Department of Geosciences The University of Tulsa Tulsa Oklahoma USA
| | - Sujith Ravi
- Department of Earth and Environmental Science Temple University Philadelphia Pennsylvania USA
| | - Guan Wang
- Department of Geosciences The University of Tulsa Tulsa Oklahoma USA
| | - R. Scott Van Pelt
- Wind Erosion and Water Conservation Research USDA‐ARS Big Spring Texas USA
| | - Thomas E. Gill
- Department of Earth, Environmental and Resource Sciences and Environmental Science & Engineering Program University of Texas at El Paso El Paso Texas USA
| | - Joel B. Sankey
- Southwestern Biological Science Center, Grand Canyon Monitoring and Research Center U.S. Geological Survey Flagstaff Arizona USA
| |
Collapse
|
3
|
Azareh A, Rahmati O, Rafiei-Sardooi E, Sankey JB, Lee S, Shahabi H, Ahmad BB. Modelling gully-erosion susceptibility in a semi-arid region, Iran: Investigation of applicability of certainty factor and maximum entropy models. Sci Total Environ 2019; 655:684-696. [PMID: 30476849 DOI: 10.1016/j.scitotenv.2018.11.235] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Gully erosion susceptibility mapping is a fundamental tool for land-use planning aimed at mitigating land degradation. However, the capabilities of some state-of-the-art data-mining models for developing accurate maps of gully erosion susceptibility have not yet been fully investigated. This study assessed and compared the performance of two different types of data-mining models for accurately mapping gully erosion susceptibility at a regional scale in Chavar, Ilam, Iran. The two methods evaluated were: Certainty Factor (CF), a bivariate statistical model; and Maximum Entropy (ME), an advanced machine learning model. Several geographic and environmental factors that can contribute to gully erosion were considered as predictor variables of gully erosion susceptibility. Based on an existing differential GPS survey inventory of gully erosion, a total of 63 eroded gullies were spatially randomly split in a 70:30 ratio for use in model calibration and validation, respectively. Accuracy assessments completed with the receiver operating characteristic curve method showed that the ME-based regional gully susceptibility map has an area under the curve (AUC) value of 88.6% whereas the CF-based map has an AUC of 81.8%. According to jackknife tests that were used to investigate the relative importance of predictor variables, aspect, distance to river, lithology and land use are the most influential factors for the spatial distribution of gully erosion susceptibility in this region of Iran. The gully erosion susceptibility maps produced in this study could be useful tools for land managers and engineers tasked with road development, urbanization and other future development.
Collapse
Affiliation(s)
- Ali Azareh
- Department of Geography, University of Jiroft, Kerman, Iran
| | - Omid Rahmati
- Young Researchers and Elites Club, Khorramabad Branch, Islamic Azad University, Khoramabad, Iran
| | | | - Joel B Sankey
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, 2255 N. Gemini Drive, Flagstaff, AZ 86001, USA
| | - Saro Lee
- Geoscience Platform Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 305350, Republic of Korea.
| | - Himan Shahabi
- Department of Geomorphology, Faculty of Natural Resources, University of Kurdistan, Sanandaj, Iran
| | - Baharin Bin Ahmad
- Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru, Malaysia
| |
Collapse
|
4
|
Sankey JB, Ravi S, Wallace CSA, Webb RH, Huxman TE. Quantifying soil surface change in degraded drylands: Shrub encroachment and effects of fire and vegetation removal in a desert grassland. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jg002002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|