Ian Walker

Biography

Ian Walker is a physical geographer and geomorphologist with expertise in sediment transport and erosion processes, coastal and aeolian landscapes, environmental fluid dynamics, sand dunes, beach-dune interaction, and climate variability and change impacts in the coastal zone. A major thrust of his work now focuses on informing environmental restoration and development of 'nature-based solutions' to enhance coastal resilience to sea-level rise and to mitigate dust emissions to improve regional air quality. 

Dr. Walker holds a B.Sc. from the University of Toronto and a Ph.D. from the University of Guelph, Canada. He joined UCSB in 2020 and previously held faculty positions at Arizona State University (2016-2020) and the University of Victoria, Canada (2000-2016). To date, he has authored over 100 scientific journal articles and book chapters and has secured over $10.5M to support his research and student training programs. Professor Walker's research is highly collaborative and involves partnerships with state and federal agencies, First Nations, NGOs, and community groups. Current partners include: US Geological Survey, US Fish & Wildlife Service, Vandenberg Space Force Base, California Dept. of Parks & Recreation, Morro Bay National Estuary Program, Point Blue Conservation Science, Humboldt Bay Friends of the Dunes, The Nature Conservancy, and California Sea Grant.

Professor Walker has served on several advisory panels for the National Academies of Science, Engineering & Medicine (Owens Lake Scientific Advisory Panel), the State of California Department of Parks & Recreation (Oceano Dunes Scientific Advisory Group), the UCSB Sea-Level Rise Adaptation Planning Committee, and the advisory team for California’s Fifth Climate Change Assessment.  He is also a member of the editorial boards for Earth Surface Processes & Landforms, Annals of the American Association of Geographers, Journal of Coastal Research, and Coastal Futures. In 2025, he was awarded the R.J. Russell Award for major contributions to coastal and marine sciences by the American Association of Geographers, Coastal & Marine Specialty Group. Dr. Walker teaches courses on introductory climatology and oceanography, geomorphology, close range remote sensing, and research development. Student training is key to his research program and, to date, he has mentored over 90 students and postdocs, 48 as lead advisor.

Research

Professor Walker’s research examines sedimentary landscapes and processes in coastal and inland areas using a variety of field- and lab-based methods. Research topics include: sediment transport and flow dynamics over complex terrain, coastal erosion and beach-dune recovery, restoration of coastal dunes, nature-based solutions for coastal resilience and improved air quality, sea-level changes (past and present), coastal landscape evolution, geoarchaeology, sedimentological signatures of human activities, climate change impacts and adaptation, and planetary geology. His research uses a variety of methods to detect, quantify, and interpret landscape dynamics and evolution including field experiments on sediment transport and beach-dune interaction, spatial-temporal change detection using terrestrial laser scanning (TLS) and uncrewed aerial systems (UAS), sedimentological investigations of relict landscapes and archaeological sites, and high resolution microscopy of sediment deposits. He also conducts research on the interactions between flow dynamics, sediment transport, vegetation, and sedimentary bedforms using wind tunnel simulations, computational fluid dynamics (CFD) modeling, and particle imaging velocimetry (PIV). Dr. Walker's research has explored sedimentary landscapes around the world and current projects include a statewide assessment of coastal dune ecosystems and their potential as a nature-based solution to mitigate coastal erosion, flooding, and sea-level rise, and research on how ecosystem restoration can be used to mitigate dust emissions and improve regional air quality at the Oceano Dunes and Owens Lake in California.

Selected Publications

Smyth, TAG, Pagon, T, Walker, IJ. (2025). Exploring wind flow dynamics in foredune notches using Computational Fluid Dynamics (CFD). Coastal Engineering, 195: 104646. https://doi.org/10.1016/j.coastaleng.2024.104646

Silva, GD, Roberts, DA, Byrd, KB, Chadwick, KD, Walker, IJ, & King, JY. (2025). Using imaging spectroscopy and elevation in machine learning to estimate soil salinity in intermittently tidal wetlands. Ecosphere, 16(8), e70356. https://doi.org/10.1002/ecs2.70356

National Academies of Sciences, Engineering & Medicine, Owens Lake Science Advisory Panel (Russell, A, Aarons, S, Bahreni, R, Dubois, D, Eviner, V, Mahan, S, Moore, T, Okin, G, Or, D, Van Pelt, S, Vekatram, A, Walker, IJ. (2025). Off-Lake Sources of Airborne Dust in Owens Valley, California. National Academies Press. 154p. https://www.nationalacademies.org/our-work/owens-lake-scientific-advisory-panel-off-lake-sources-of-airborne-dust-in-owens-valley-california

Emery, K, Baxter, T, Callahan, M, Cavanaugh, K, Dugan, J, Engeman, L, Hubbard, D, Johnston, K, Walker, IJ, & Wisniewski, J. (2024). Evaluating the response of a pilot dune restoration project on an urban beach to an extreme wave surge event. Shore & Beach, 92(4). http://dx.doi.org/10.34237/1009243

Davidson-Arnott, R, Ollerhead, J, George, E, Houser, C, Bauer, B, Hesp, P, Walker, IJ, Delagado-Fernandez, I, & van Proosdij, D. (2024). Assessing the impact of hurricane Fiona on the coast of PEI National Park and implications for the effectiveness of beach-dune management policies. Journal of Coastal Conservation, 28(3): 52. https://doi.org/10.1007/s11852-024-01050-5

Gómez, JF, Kwoll, E, Walker, IJ, & Orejarena, AF. (2023). Examining the hydro-climatic drivers of lagoon breaching and healing in a deltaic barrier. Geosciences, 13(4), 118. https://doi.org/10.3390/geosciences13040118

Walker, IJ, Hilgendorf, Z, Gillies, JA, Turner, CM, Furtak‐Cole, E, & Nikolich, G. (2023). Assessing performance of a “nature‐based” foredune restoration project, Oceano Dunes, California, USA. Earth Surface Processes and Landforms, 48(1), 143-162. https://doi.org/10.1002/esp.5478

Hilgendorf, Z, Walker, IJ, Pickart, AJ, & Turner, CM. (2022). Dynamic restoration and the impact of native versus invasive vegetation on coastal foredune morphodynamics, Lanphere Dunes, California, USA. Earth Surface Processes and Landforms, 47(13), 3083-3099. https://doi.org/10.1002/esp.5445

Furtak-Cole, E, Gillies, JA, Hilgendorf, Z, Walker, IJ, & Nikolich, G. (2022). Simulation of flow and shear stress distribution on the Oceano Dunes, implications for saltation and dust emissions. Environmental Fluid Mechanics, 22(6), 1399-1420. https://doi.org/10.1007/s10652-022-09902-0

Bauer, BO, Hesp, PA, Smyth, TAG, Walker, IJ, Davidson‐Arnott, RG, Pickart, AJ, Grilliot, M, & Rader, A. (2022). Air flow and sediment transport dynamics on a foredune with contrasting vegetation cover. Earth Surface Processes and Landforms, 47(11), 2811-2829. https://doi.org/10.1002/esp.5425

Walker, IJ, Hesp, PA, & Smyth, TAG. (2022). Airflow dynamics over unvegetated and vegetated dunes. Chapter 7.16 in: Lancaster, N, Vol. 7: 415-453. Aeolian & Desert Geomorphology. In: Shroder, JF (editor) “Treatise on Geomorphology”. Second Edition. Elsevier: Oxford. https://doi.org/10.1016/B978-0-12-818234-5.00136-X 

Hesp, PA, & Walker, IJ. (2022). Coastal dunes. Chapter 7.21 in: Lancaster, N, Vol. 7: 540-591. Aeolian & Desert Geomorphology. In: Shroder, JF (editor) “Treatise on Geomorphology”. Second Edition. Elsevier: Oxford. https://doi.org/10.1016/B978-0-12-818234-5.00220-0

Walker, IJ, Turner, C, Hilgendorf, Z. (2021). Comparing UAS and terrestrial laser scanning (TLS) methods for geomorphic change detection. Chapter 15 in: Frazier, AE & Singh, KK (eds), Fundamentals of Capturing and Processing Drone Imagery and Data. CRC Press, Taylor & Francis. 385 p. http://dx.doi.org/10.1201/9780429283239

Hilgendorf, Z, Marvin, MC, Turner, CM, Walker, IJ. (2021). Assessing geomorphic change in restored coastal dune ecosystems using a multi-platform aerial approach. Remote Sensing, 13, 354. https://doi.org/10.3390/rs13030354

Cheung, SY, Walker, IJ, Myint, S, Dorn, R. (2021). Assessing land degradation induced by recreational activities in Algodones Dunes, California. Journal of Arid Environments 185: 104334 https://doi.org/10.1016/j.jaridenv.2020.104334

Walker, IJ. (2020). Aeolian (windblown) sand transport over beaches. Chapter 10. In Jackson, DWJ, and Short, A (eds). Sandy Beach Morphodynamics. 55 p. Elsevier. http://dx.doi.org/10.1016/B978-0-08-102927-5.00010-2

Nelson, L, Cade-Menun, BJ, Walker, IJ, Sanborn, P. (2020). Soil phosphorus dynamics across a Holocene chronosequence of aeolian sand dunes in a hypermaritime environment on Calvert Island, BC, Canada. Frontiers in Forests and Global Change. 3(83). https://doi.org/10.3389/ffgc.2020.00083

Grilliot, MJ, Walker, IJ, Bauer, BO. (2019). The role of large woody debris in beach-dune interaction. Journal of Geophysical Research: Earth Surface 124(12), 2854-2876. https://doi.org/10.1029/2019JF005120

Smyth, TA, Hesp, PA, Walker, IJ, Wasklewicz, T, Gares, P, Smith, AB. (2019). Topographic change and numerically modelled near surface wind flow in a bowl blowout. Earth Surface Processes and Landforms. http://dx.doi.org/10.1002/esp.4625

Lausanne, A, Fedje, D, Mackie, Q, Walker, IJ. (2019). Identifying potential geoarchaeological sites with high prospecting potential using aerial LIDAR imaging and GIS on Quadra Island, Canada. Journal of Island & Coastal Archaeology. https://doi.org/10.1080/15564894.2019.1659884

Rader, AM, Pickart, A, Walker, IJ, Hesp, PA, Bauer, BO. (2018). Foredune morphodynamics and sediment budgets at seasonal to decadal scales: Humboldt Bay National Wildlife Refuge, California, USA. Geomorphology 318: 69-87. https://doi.org/10.1016/j.geomorph.2018.06.003

Davidson‐Arnott, R, Hesp, PA, Ollerhead, J, Walker, IJ, Bauer, BO, Delgado‐Fernandez, I, & Smyth, T. (2018). Sediment budget controls on foredune height: Comparing simulation model results with field data. Earth Surface Processes and Landforms, 43(9), 1798-1810. https://doi.org/10.1002/esp.4354

Walker, IJ, Davidson-Arnott, RGD, Bauer, BO, Hesp, PA, Ollerhead, J, Delgado-Fernandez, I, & Smyth, TAG. (2017). Scale-dependent perspectives on the geomorphology of beach-dune systems. Earth Science Reviews, 171: 220-253. http://dx.doi.org/10.1016/j.earscirev.2017.04.011

Eamer, JBR, Shugar, DH, Walker, IJ, Lian, O, & Neudorf, CM. (2017). Distinguishing depositional setting for sandy deposits in coastal landscapes using grain shape. Journal of Sedimentary Research 87: 1-11. http://dx.doi.org/10.2110/jsr.2016.92

Darke, IB, Walker, IJ, Hesp, PA. (2016). Beach-dune sediment budgets and dune morphodynamics following coastal dune restoration, Wickaninnish Dunes, Canada. Earth Surface Processes and Landforms, 41(10), 1370-1385. http://dx.doi.org/10.1002/esp.3910

Barnard P, Short A, Harley M, Splinter K, Vitousek S, Turner I, Allan J, Banno M, Bryan K, Doria A, Hansen J, Kato S, Kuriyama Y, Randall-Goodwin E, Ruggiero P, Walker IJ, & Heathfield D. (2016). Coastal vulnerability across the Pacific dominated by El Niño/Southern Oscillation. Nature Geoscience 8: 801–807. http://dx.doi.org/10.1038/NGEO2539