© 2020 IIETA. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).
OPEN ACCESS
Mountainous forested regions are the major sources of water for meeting downstream water demands in many parts of the world, including the United States, where two-thirds of the freshwater supply is estimated to originate from these areas. Wildfires pose significant threats to downstream urban infrastructure and livelihoods by impacting the timing, quantity and quality of waters emerging from these forested ecosystems. Wildfires affect key processes of the water cycle by reducing infiltration and interception, resulting in higher runoff volumes. Predicting post-fire flood events is important for proper water management and planning, including the safety of downstream communities. The objective of the study is to determine how changes in the locations of wildfire events coupled with the type (severity) of fire events affect peak flow regimes of high mountain watersheds. American Fork, a high mountain forest watershed in Utah with an area of 60 sq. miles (155 sq. km) and elevations ranging from 5,000 ft. to 11,700 ft. (1550 m to 3600 m), is taken as the study area. A historical fire event that took place in a neighbouring watershed was superimposed on three different locations of the studying watershed with varying severity. A hydrologic model named Distributed Hydrologic Soil vegetation Model was used to predict the flows due to changes in land cover and hydrologic processes for different wildfire events. Changes in peak flow due to different wildfire events at different locations of the watershed are analysed to estimate how location and type of wildfire events affect the peak flow regimes of the watershed and how thus it affects the overall downstream water supply. This study also identifies the critical location in the watershed for which the peak flow regime of the watershed will be most vulnerable due to a certain extent of wildfire.
climate change, modelling, snowmelt, wildfire, sustainability, water planning and management
[1] DeBano, L.F., Neary, D.G. & Ffolliott, P.F., Fire’s Effects on Ecosystems. John Wiley & Sons, Inc.: New York, pp. 333, 1998.
[2] Neary, D.G., Koestner, K.A. & Youberg, A., Hydrologic impacts of high severity wildfire: learning from the past and preparing for the future. Presented at the 24th Annual Symposium of the Arizona Hydrological Society, Flagstaff, Arizona, 2011.
[3] Neary, D.G., Ryan, K.C. & DeBano, L.F., Wildland fire in ecosystems: effects of fire on soils and water. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, General Technical Report, 4, pp. 250, 2008.
[4] Neary, D.G., Klopatek, C.C., DeBano, L.F. & Ffolliott, P.F., Fire effects on belowground sustainability: a review and synthesis. Forest Ecology and Management, 122, pp. 51–71, 1999.
[5] Benavides-Solorio, J. & MacDonald, L. H., Post-fire runoff and erosion from simulated rainfall on small plots, Colorado Front Range. Hydrological Processes, 15, pp. 2931-2952, 2001.
[6] Shakesby, R.A., Coelho, C.O.A., Ferreira, A.D., Terry, J.P. & Walsh, R. P. D., Wildfire impacts on soil erosion and hydrology in wet Mediterranean forest, Portugal. International Journal of Wildland Fire, 3, pp. 95-110, 1993.
[7] Cerda, A., Changes in Overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes, 12, pp.1031-1042, 1998.
[8] Fernquist, J. & Floraberger, I., Fire and post-fire soil erosion in Western Cape, South Africa: field observation and management practices. Unpublished, Committee of Tropical Ecology, Uppsala University, Sweden, 2003.
[9] Smith, H.G., Sheridan, G.J., Lane, P.N.J.J., Nyman, P. & Haydon, S. Wildfire effects on water quality in forest catchments: a review with implications for water supply. Journal of Hydrology, 396, pp. 170-192, 2011.
[10] Stein, S.M., McRoberts, R.E., Alig, R.J., Nelson, M.D., Theobald, D.M., Eley, M., Dechter, M. & Carr, M. Forests on the edge: housing development on America’s private forests. USDA Forest Service General Technical Report, 1–16, 2005.
[11] Bardsley, T., Wood, A., Hobbins, M., Kirkham, T., Briefer, L., Niermeyer, J. & Burian, S. Planning for an uncertain future: climate change sensitivity assessment toward adaptation planning for public water supply. Earth Interactions, 17(23), pp. 1–26, 2013.
[12] Dennison, P.E., Brewer, S.C., Arnold, J.D. & Moritz, M.A. Large wildfire trends in the western United States 1984–2011. Geophysical Research Letters, 41, pp. 2928-2933, 2014.
[13] Hawbaker, T. J. & Zhu, Z. Projected future wildland fires and emissions for the Western United States, in Baseline and Projected Future Carbon Storage and Greenhouse-Gas Fluxes in Ecosystems of the Western United States. U.S. Geological Survey Professional Paper 1797, pp. 97-108, 2012a.
[14] Ryan, K.C. & Noste, N.V. Evaluating prescribed fires. In: J.E. Lotan, B.M., Kilgore, W.C. Fischer, and R.W. Mutch (Tech. Coords.) Proceedings, Symposium, and Workshop on Wilderness Fire. U.S. Forest Service, Ogden, Utah, pp. 230–238, 1983.
[15] Meyer, G.A., Wells, S.G. & Jull, A.J.T. Fire and alluvial chronology in Yellowstone National Park: climatic and intrinsic controls on Holocene geomorphic processes. Geological Society of America Bulletin, 107, pp. 1211–1230, 1995.
[16] Rhoades, C.C., Chow, A.T., Covino, T.P., Fegel, T.S., Pierson, D.N. & Rhea, A.E. The legacy of a severe wildfire on stream nitrogen and carbon in headwater catchments. Ecosystems, 22, pp. 643-657, 2019.
[17] Sankey, J. B., Kreitler, J., Hawbaker, T. J., McVay, J. L., Miller, M. E., Mueller, E. R., Nicole, M.V., Scott, E.L. & Sankey, T. T. Climate, wildfire, and erosion ensemble foretells more sediment in western USA watersheds. Geophysical Research Letters, 44(17), pp. 8884–8892, 2017. https://doi.org/10.1002/2017GL073979.
[18] Flannigan, M.D., Stocks, B.J. & Wotton, B.M., Climate change and forest fires. Science of the Total Environment, 262(3), pp. 221-229, 2000.
[19] Abatzoglou, J.T. & Williams, P., Impact of anthropogenic climate change on wildfire across western U.S. forests. Proceedings of the National Academy of Sciences, 113(42), 11770-11775, 2016.
[20] Jain, T.B. & Graham, R.T., The relation between tree burn severity and forest structure in the Rocky Mountains. USDA Forest Service General Technical Report PSWGTR-203, 2007.
[21] Keeley, J.E., Fire intensity, fire severity and burn severity: a brief review and suggested usage. International Journal of Wildland Fire, 18, pp. 116-126, 2009.
[22] Cansler, C.A. & McKenzie, D., Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA. Ecological Applications, 24(5), pp. 1037-1056, 2014.
[23] Wigmosta, M.S., Vail, L.W. & Lettenmaier, D.P., A distributed hydrology soil vegetation model for complex terrain. Water Resources Research, 30(6), pp. 1665–1679, 1994.
[24] Beckers, J., Smerdon, B., Redding, T., Anderson, A., Pike, R. & Werner, A.T., Hydrologic models for forest management applications. Part 1: model selection. Streamline Watershed Management Bulletin, 13, pp. 35–44, 2009.