Andrew W. Tranmer, Ph.D.

• Hydrology
• Water resources
• Numerical and physical modeling
• Fluvial geomorphology
• Sediment transport
• Channel evolution
• River restoration

Andy Tranmer’s research addresses the physical processes of complex aquatic systems and their respective influence on ecological resilience for the purposes of responsible alluvial design and river restoration. A greater understanding of the physical mechanics occurring in the riparian corridor allow for prediction of geomorphic evolution, habitat suitability and ecosystem performance to guide sustainable resource management and public policy. A complementary suite of field, numerical and laboratory studies are employed to further the current state of knowledge in these dynamic environments. Recent work in Idaho assessed reservoir operations to guide floodplain sustainability and endangered species recovery. International projects examined pristine fluvial networks in Chilean Patagonia and large-scale flume experiments in Korea to quantify transport mechanics during alluvial channel evolution.

• Tranmer, A.W., *Bertagnoli, A., Hurst, A., Sholtes, J., Tonina, D., 2025. Pools as reach-scale thermal regulators. Science of the Total Environment 958: 177890. https://doi.org/10.1016/j.scitotenv.2024.177890.
• Benjankar, R., Tranmer, A.W., Tonina, D., 2025. The importance of floodplain width on hydraulic variability and aquatic-riparian habitat in semi-confined, regulated river systems. Ecological Engineering 216: 107637. https://doi.org/10.1016/j.ecoleng.2025.107637.
• *Frye, J., Tranmer, A.W., *Bertagnoli, A., Hurst, A., Ubing, C., Sholtes, J., Tonina, D., 2025. Morphology-induced thermal refuge in gravel-bed rivers. Hydrological Processes 39: e70107. https://doi.org/10.1002/hyp.70107.
• *Bertagnoli, A., Luce, C., van Kampen, R., Schneidewind, U., van Berkel, M., Tranmer, A.W., Vandersteen, G., Krause, S., Tonina, D., 2024. iFLOW: A framework and GUI to quantify effective thermal diffusivity and advection in permeable materials from temperature time series. Water Resources Research 60: e2024WR037370. https://doi.org/10.1029/2024WR037370.
• Tranmer, A.W., Ji, U., Ahn, M., Jung, S.H., Yager, E.M., 2024. Characterizing erosion and deposition in and around riparian vegetation patches: Complex flow hydraulics, sediment supply, and morphodynamic feedbacks. Water Resources Research 60: e2023WR034859. https://doi.org/10.1029/2023WR034859.
• Tranmer, A.W., Benjankar, R., Tonina, D., Vidergar, D., 2023. Identifying failure mechanisms of native riparian forest regeneration in a variable-width floodplain using a spatially distributed riparian forest recruitment model. Ecological Engineering 187: 106865. https://doi.org/10.1016/j.ecoleng.2022.106865.
• Tranmer A.W., Caamaño, D., *Arteaga, A.E., 2022. Urban stream syndrome: quantifying topographic variation along an urban-rural gradient. Journal of Environmental Management 317: 115413. https://doi.org/10.1016/j.jenvman.2022.115413.
• Tranmer A.W., Caamaño, D., Clayton, S.R., Giglou, A.N., Goodwin, P., Buffington, J.M., Tonina, D., 2022. Testing the effective-discharge paradigm in gravel-bed river restoration. Geomorphology 403: 108139. https://doi.org/10.1016/j.geomorph.2022.108139.
• Tranmer, A.W., Benjankar, R., Tonina, D., 2020. Post-wildfire riparian forest recovery processes along a regulated river corridor. Forest Ecology and Management 478: 118513.
  https://doi.org/10.1016/j.foreco.2020.118513.
• Benjankar, R., Tranmer, A.W., Tonina, D., Vidergar, D., 2020. Riparian Vegetation Model to Predict Seedling Recruitment and Restoration Alternatives. Journal of Environmental Management 276: 111339. https://doi.org/10.1016/j.jenvman.2020.111339.
• Tranmer A.W., Marti, C., Goodwin, P., Tonina, D., Benjankar, R., Weigel, D.E., Imberger, J., 2020. Coupled reservoir-river systems: Lessons from an integrated aquatic ecosystem assessment. Journal of Environmental Management 260: 110107. https://doi.org/10.1016/j.jenvman.2020.110107.
• Tranmer, A.W., Caamaño, D., Goodwin, P., 2020. Evaluation of extremal hypotheses in an undeveloped alluvial river. Progress in Physical Geography 44: 514-533. https://doi.org/10.1177/0309133319886721.
• Tranmer, A.W., Caamaño, D., Goodwin, P., 2020. Identifying dynamic equilibrium of an undeveloped alluvial stream by extremal hypotheses. Catena 194: 104680. https://doi.org/10.1016/j.catena.2020.104680.
• *Fuentes-Aguilera, P., Caamaño, D., Alcayaga, H., Tranmer, A.W., 2020. The Influence of Pool-Riffle Morphological Features on River Mixing. Water 12: 1145, https://doi.org/10.3390/w12041145.
• Tranmer, A.W., Goodwin, P., Caamaño, D., 2018. Assessment of alluvial trends toward dynamic equilibrium under chronic climatic forcing. Advances in Water Resources 120: 19-34. https://doi.org/10.1016/j.advwatres.2017.11.015.
• Tranmer, A.W., Marti, C.L., Tonina, D., Benjankar, R., Weigel, D.E., Vilhena, L.C., McGrath, C., Goodwin, P., Tiedemann, M., McKean, J., Imberger, J., 2018. A hierarchical modelling framework for assessing physical and biochemical characteristics of a regulated river. Ecological Modelling 368: 78-93. https://doi.org/10.1016/j.ecolmodel.2017.11.010.
• Weigel, D.E., Vilhena, L.C., Woods, P., Tonina, D., Tranmer, A.W., Benjankar, R., Marti, C.L., Goodwin, P., 2017. Aquatic habitat response to climate-driven hydrologic regimes and water operations in a montane reservoir in the Pacific Northwest, USA. Aquatic Sciences 79: 953, 953-966. https://doi.org/10.1007/s00027-017-0544-1.
• Tranmer, A.W., Goodwin, P., Tonina, D., Benjankar, R., Tiedemann, M. 2015. Floodplain sustainability and dynamic-equilibrium conditions in a canyon environment. Geomorphology 250: 147-158. https://doi.org/10.1016/j.geomorph.2015.09.001.

• Geomorphic evolution of deglaciating catchments
• Integrated reservoir-river interactions
• Effects of vegetation and sediment transport on river channel evolution
• Geomorphic sustainability of floodplains in the landscape