Articles | Volume 25, issue 6
https://doi.org/10.5194/hess-25-3713-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-25-3713-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Drought onset and propagation into soil moisture and grassland vegetation responses during the 2012–2019 major drought in Southern California
Maria Magdalena Warter
CORRESPONDING AUTHOR
School of Earth and Environmental Sciences, Cardiff University,
Cardiff, CF10 3AT, United Kingdom
Michael Bliss Singer
School of Earth and Environmental Sciences, Cardiff University,
Cardiff, CF10 3AT, United Kingdom
Water Research Institute, Cardiff University, Cardiff, CF10 3AX,
United Kingdom
Earth Research Institute, University of California Santa Barbara,
Santa Barbara, CA 93106-3060, USA
Mark O. Cuthbert
School of Earth and Environmental Sciences, Cardiff University,
Cardiff, CF10 3AT, United Kingdom
Water Research Institute, Cardiff University, Cardiff, CF10 3AX,
United Kingdom
Connected Waters Initiative Research Centre (CWI), School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
Dar Roberts
Department of Geography, University of California Santa Barbara, Santa Barbara, CA 93117, USA
Kelly K. Caylor
Earth Research Institute, University of California Santa Barbara,
Santa Barbara, CA 93106-3060, USA
Department of Geography, University of California Santa Barbara, Santa Barbara, CA 93117, USA
Bren School of Environmental Science and Management, University of
California Santa Barbara, Santa Barbara, CA 93117, USA
Romy Sabathier
School of Earth and Environmental Sciences, Cardiff University,
Cardiff, CF10 3AT, United Kingdom
John Stella
Department of Forest and Natural Resources Management, State
University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
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Isaac Kipkemoi, Katerina Michaelides, Rafael Rosolem, and Michael Bliss Singer
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-48, https://doi.org/10.5194/hess-2021-48, 2021
Manuscript not accepted for further review
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Gabriel C. Rau, Mark O. Cuthbert, R. Ian Acworth, and Philipp Blum
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Cited articles
Abatzoglou, J. T. and Williams, A. P.: Impact of anthropogenic climate change on wildfire across western US forests, P. Natl. Acad. Sci. USA, 113, 11770–11775, https://doi.org/10.1073/pnas.1607171113, 2016.
Aghakouchak, A., Ragno, E., and Love, C.: Projected Changes in Californias
Precipitation Intensity-Duration-Frequency Curves, in: California's Fourth
Climate Change Assessment, California Energy Commission, CA, USA, p. 32, 2018.
Allen, R. G., Pereira, L. S., Raes, D., and Smith, M.: FAO Irrigation and
Crop evapotranspiration (Guidelines for computing crop water requirements), Drainage Paper No. 56, available at: http://www.fao.org/3/x0490e/x0490e00.htm (last access: 1 April 2021), 1998.
Asner, G. P., Brodrick, P. G., Anderson, C. B., Vaughn, N., Knapp, D. E., and
Martin, R. E.: Progressive forest canopy water loss during the 2012–2015 California drought, Proc. Natl. Acad. Sci. USA, 113, E249–E255,
https://doi.org/10.1073/pnas.1523397113, 2016.
Ault, T. R., Mankin, J. S., Cook, B. I., and Smerdon, J. E.: Relative impacts
of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest, Sci. Adv., 2, 1–9, https://doi.org/10.1126/sciadv.1600873, 2016.
Berg, N. and Hall, A.: Increased interannual precipitation extremes over California under climate change, J. Climate, 28, 6324–6334, https://doi.org/10.1175/JCLI-D-14-00624.1, 2015.
Berg, N. and Hall, A.: Anthropogenic warming impacts on California snowpack
during drought, Geophys. Res. Lett., 44, 2511–2518, https://doi.org/10.1002/2016GL072104, 2017.
Bradford, J. B., Schlaepfer, D. R., Lauenroth, W. K., and Palmquist, K. A.:
Robust ecological drought projections for drylands in the 21st century, Global Change Biol., 23, 3906–3919, https://doi.org/10.1111/gcb.15075, 2020.
Breshears, D. D., Cobb, N. S., Rich, P. M., Price, K. P., Allen, C. D., Balice, R. G., Romme, W. H., Kastens, J. H., Floyd, M. L., Belnap, J.,
Anderson, J. J., Myers, O. B., and Meyer, C. W.: Regional vegetation die-off
in response to global-change-type drought, P. Natl. Acad. Sci. USA, 102,
15144–15148, https://doi.org/10.1073/pnas.0505734102, 2005.
Briggs, L. J. and Shantz, H. L.: The Wilting Coefficient and Its Indirect
Determination, Bot. Gaz., 53, 20–37, 1912.
Caylor, K. K., D'Odorico, P., and Rodriguez-Iturbe, I.: On the ecohydrology of structurally heterogeneous semiarid landscapes, Water Resour. Res., 42, 1–13, https://doi.org/10.1029/2005WR004683, 2006.
Caylor, K. K., Scanlon, T. M., and Rodriguez-Iturbe, I.: Ecohydrological
optimization of pattern and processes in water-limited ecosystems: A
trade-off-based hypothesis, Water Resour. Res., 45, 1–15, https://doi.org/10.1029/2008WR007230, 2009.
Coates, A. R., Dennison, P. E., Roberts, D. A., and Roth, K. L.: Monitoring
the impacts of severe drought on southern California Chaparral species using
hyperspectral and thermal infrared imagery, Remote Sens., 7, 14276–14291, https://doi.org/10.3390/rs71114276, 2015.
Cook, B. I., Ault, T. R., and Smerdon, J. E.: Unprecedented 21st century
drought risks in the American south west and central plains, Sci. Adv., 1,
e1400081, https://doi.org/10.1126/sciadv.1400082, 2015.
Cuthbert, M. O., MacKay, R., and Nimmo, J. R.: Linking soil moisture balance
and source-responsive models to estimate diffuse and preferential components of groundwater recharge, Hydrol. Earth Syst. Sci., 17, 1003—1019,
https://doi.org/10.5194/hess-17-1003-2013, 2013.
Cuthbert, M. O., Taylor, R. G., Favreau, G., Todd, M. C., Shamsudduha, M.,
Villholth, K. G., MacDonald, A. M., Scanlon, B. R., Kotchoni, D. O. V., Vouillamoz, J. M., Lawson, F. M. A., Adjomayi, P. A., Kashaigili, J., Seddon, D., Sorensen, J. P. R., Ebrahim, G. Y., Owor, M., Nyenje, P. M., Nazoumou, Y., Goni, I., Ousmane, B. I., Sibanda, T., Ascott, M. J., Macdonald, D. M. J., Agyekum, W., Koussoubé, Y., Wanke, H., Kim, H., Wada, Y., Lo, M. H., Oki, T., and Kukuric, N.: Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa, Nature, 572, 230–234, https://doi.org/10.1038/s41586-019-1441-7, 2019.
Diffenbaugh, N. S., Swain, D. L., and Touma, D.: Anthropogenic warming has
increased drought risk in California, P. Natl. Acad. Sci. USA, 112, 3931–3936, https://doi.org/10.1073/pnas.1422385112, 2015.
D'Odorico, P., Caylor, K., Okin, G. S., and Scanlon, T. M.: On soil
moisture-vegetation feedbacks and their possible effects on the dynamics of
dryland ecosystems, J. Geophys. Res.-Biogeo., 112, 1–10, https://doi.org/10.1029/2006JG000379, 2007.
Dong, C., MacDonald, G. M., Willis, K., Gillespie, T. W., Okin, G. S., and
Williams, A. P.: Vegetation Responses to 2012–2016 Drought in Northern and
Southern California, Geophys. Res. Lett., 3810–3821, https://doi.org/10.1029/2019GL082137, 2019.
Evans, C. M., Dritschel, D. G., and Singer, M. B.: Modeling Subsurface Hydrology in Floodplains, Water Resour. Res., 54, 1428–1459, https://doi.org/10.1002/2017WR020827, 2018.
Fettig, C. J., Mortenson, L. A., Bulaon, B. M., and Foulk, P. B.: Tree mortality following drought in the central and southern Sierra Nevada, California, U.S., Forest. Ecol. Manage., 432, 164–178, https://doi.org/10.1016/j.foreco.2018.09.006, 2019.
Gillespie, T. W., Ostermann-kelm, S., Dong, C., Willis, K. S., Okin, G. S., and Macdonald, G. M.: Monitoring changes of NDVI in protected areas of
southern California, Ecol. Indic., 88, 485–494, https://doi.org/10.1016/j.ecolind.2018.01.031, 2018.
Glenn, E. P., Neale, C. M. U., Hunsaker, D. J., and Nagler, P. L.: Vegetation
index-based crop coefficients to estimate evapotranspiration by remote sensing in agricultural and natural ecosystems, Hydrol. Process., 25, 4050–4062, https://doi.org/10.1002/hyp.8392, 2011.
Goulden, M. L. and Bales, R. C.: California forest die-off linked to multi-year deep soil drying in 2012–2015 drought, Nat. Geosci., 12, 632–637, https://doi.org/10.1038/s41561-019-0388-5, 2019.
Gremer, J. R., Bradford, J. B., Munson, S. M., and Duniway, M. C.: Desert
grassland responses to climate and soil moisture suggest divergent
vulnerabilities across the southwestern United States, Global Change Biol.,
21, 4049–4062, https://doi.org/10.1111/gcb.13043, 2015.
Gu, Y., Hunt, E., Wardlow, B., Basara, J. B., Brown, J. F., and Verdin, J. P.: Evaluation of MODIS NDVI and NDWI for vegetation drought monitoring using Oklahoma Mesonet soil moisture data, Geophys. Res. Lett., 35, 1–5, https://doi.org/10.1029/2008GL035772, 2008.
Hunsaker, D. J., Pinter, P. J., and Kimball, B. A.: Wheat basal crop coefficients determined by normalized difference vegetation index, Irrig.
Sci., 24, 1–14, https://doi.org/10.1007/s00271-005-0001-0, 2005.
IDEAS: IDEAS Home Page, available at: https://ideas.geog.ucsb.edu, last access: June 2021.
Keeley, J. E. and Syphard, A. D.: Climate change and future fire regimes:
Examples from California, Geoscience, 6, 1–14, https://doi.org/10.3390/geosciences6030037, 2016.
Lian, X., Piao, S., Li, L. Z. X., Li, Y., Huntingford, C., Ciais, P., Cescatti, A., Janssens, I. A., Peñuelas, J., Buermann, W., Chen, A., Li,
X., Myneni, R. B., Wang, X., Wang, Y., Yang, Y., Zeng, Z., Zhang, Y., and
McVicar, T. R.: Summer soil drying exacerbated by earlier spring greening of
northern vegetation, Sci. Adv., 6, 1–12, https://doi.org/10.1126/sciadv.aax0255, 2020.
Liu, S., Roberts, D. A., Chadwick, O. A., and Still, C. J.: Spectral responses to plant available soil moisture in a Californian Grassland, Int. J. Appl. Earth Obs. Geoinf., 19, 31–44, https://doi.org/10.1016/j.jag.2012.04.008, 2012.
Ludwig, J. A., Wilcox, B. P., Breshears, D. D., Tongway, D. J., and Imeson, A. C.: Vegetation patches and runoff-erosion as interacting ecohydrological
processes in semiarid landscapes, Ecology, 86, 288–297, https://doi.org/10.1890/03-0569, 2005.
mariaw-hub: mariaw-hub/SMBM: SMBM (Version v1.0), Zenodo, https://doi.org/10.5281/zenodo.5031590, 2021.
McDowell, N., Pockman, W. T., Allen, C. D., Breshears, D. D., Cobb, N., Kolb, T., Plaut, J., Sperry, J., West, A., Williams, D. G., and Yepez, E. A.: Mechanisms of plant survival and mortality during drought: Why do some plants survive while others succumb to drought?, New Phytol., 178, 719–739, https://doi.org/10.1111/j.1469-8137.2008.02436.x, 2008.
Michaelides, K., Lister, D., Wainwright, J., and Parsons, A. J.: Vegetation
controls on small-scale runoff and erosion dynamics in a degrading dryland
environment, Hydrol. Process., 23, 1617–1630, 2009.
Nagler, P. L., Cleverly, J., Glenn, E., Lampkin, D., Huete, A., and Wan, Z.:
Predicting riparian evapotranspiration from MODIS vegetation indices and
meteorological data, Remote Sens. Environ., 94, 17–30, https://doi.org/10.1016/j.rse.2004.08.009, 2005.
NDMC: United States Drought Monitor, United States Drought Monit, available at: https://droughtmonitor.unl.edu/ (last access: 12 February 2021), 2020.
Oakley, N. S., Cannon, F., Munroe, R., Lancaster, J. T., Gomberg, D., and Martin Ralph, F.: Brief communication: Meteorological and climatological
conditions associated with the 9 January 2018 post-fire debris flows in Montecito and Carpinteria, California, USA, Nat. Hazards Earth Syst. Sci., 18, 3037–3043, https://doi.org/10.5194/nhess-18-3037-2018, 2018.
Okin, G. S., Dong, C., Willis, K. S., Gillespie, T. W., and MacDonald, G. M.:
The Impact of Drought on Native Southern California Vegetation: Remote Sensing Analysis Using MODIS-Derived Time Series, J. Geophys. Res.-Biogeo., 123, 1927–1939, https://doi.org/10.1029/2018JG004485, 2018.
Petrie, M. D., Collins, S. L., and Litvak, M. E.: The ecological role of small rainfall events in a desert grassland, Ecohydrology, 8, 1614–1622,
https://doi.org/10.1002/eco.1614, 2015.
Pierce, D. W., Kalansky, J. F., and Cayan, D. R.: Climate, Drought, and Sea
Level Rise Scenarios for the Fourth California Climate Assessment, in:
California's Fourth Climate Change Assessment, California Energy Commission, available at: https://www.climateassessment.ca.gov/ (last access: 10 August 2020), 2018.
Prugh, L. R., Deguines, N., Grinath, J. B., Suding, K. N., Bean, W. T.,
Stafford, R., and Brashares, J. S.: Ecological winners and losers of extreme
drought in California, Nat. Clim. Change, 8, 819–824, https://doi.org/10.1038/s41558-018-0255-1, 2018.
Quichimbo, E. A., Singer, M. B., and Cuthbert, M. O.: Characterizing
groundwater-surface water interactions in idealized ephemeral stream systems, Hydrol. Process., https://doi.org/10.1002/hyp.13847, in press, 2020.
Roberts, D., Bradley, E., Roth, K., Eckmann, T., and Still, C.: Linking physical geography education and research through the development of an
environmental sensing network and project-based learning, J. Geosci. Educ.,
58, 262–274, https://doi.org/10.5408/1.3559887, 2010.
Shukla, S., Safeeq, M., Aghakouchak, A., Guan, K., and Funk, C.: Temperature
impacts on the water year 2014 drought in California, Geophys. Res. Lett., 42, 4384–4393, https://doi.org/10.1002/2015GL063666, 2015.
Singer, M. B. and Michaelides, K.: Deciphering the expression of climate change within the Lower Colorado River basin by stochastic simulation of
convective rainfall, Environ. Res. Lett., 12, 104011, https://doi.org/10.1088/1748-9326/aa8e50, 2017.
Singer, M. B., Michaelides, K., and Hobley, D. E. J.: STORM 1.0: A simple,
flexible, and parsimonious stochastic rainfall generator for simulating
climate and climate change, Geosci. Model Dev., 11, 3713–3726,
https://doi.org/10.5194/gmd-11-3713-2018, 2018.
Singh, M. and Meyer, W. M.: Plant-soil feedback effects on germination and
growth of native and non-native species common across Southern California,
Diversity, 12, 217, https://doi.org/10.3390/D12060217, 2020.
Small, E. E., Roesler, C. J., and Larson, K. M.: Vegetation response to the
2012–2014 California drought from GPS and optical measurements, Remote Sens., 10, 1–16, https://doi.org/10.3390/rs10040630, 2018.
Swain, D. L., Tsiang, M., Haugen, M., Singh, D., Charland, A., Rajaratnam, B., and Diffenbaugh, N. S.: The Extraordinary California Drought of 2013/2014: Character, Context, And The Role Of Climate Change, Am. Meteorol. Soc., USA, 2014.
Thomas, B. F., Famiglietti, J. S., Landerer, F. W., Wiese, D. N., Molotch, N. P., and Argus, D. F.: GRACE Groundwater Drought Index: Evaluation of California Central Valley groundwater drought, Remote Sens. Environ., 198,
384–392, https://doi.org/10.1016/j.rse.2017.06.026, 2017.
Thorne, J. H., Boynton, R. M., Holguin, A. J., Stewart, J. A., and Bjorkman, J.: A climate change vulnerability assessment of California's terrestrial vegetation, California Department of Fish and Wildlife, University of California, Davis, USA, 2016.
Trenberth, K. E.: Changes in precipitation with climate change, Clim. Res.,
47, 123–138, https://doi.org/10.3354/cr00953, 2011.
Westra, S., Fowler, H. J., Evans, J. P., Alexander, L. V., Berg, P., Johnson, F., Kendon, E. J., Lenderink, G., and Roberts, N. M.: Future changes to the intensity and frequency of short-duration extreme rainfall, Rev. Geophys., 52, 522–555, https://doi.org/10.1002/2014RG000464, 2014.
Wilkening, J., Pearson-Prestera, W., Mungi, N. A., and Bhattacharyya, S.:
Endangered species management and climate change: When habitat conservation
becomes a moving target, Wildl. Soc. Bull., 43, 11–20, https://doi.org/10.1002/wsb.944, 2019.
Williams, A. P., Seager, R., Abatzoglou, J. T., Cook, B. I., Smerdon, J. E.,
and Cook, E. R.: Contribution of anthropogenic warming to California drought
during 2012–2014, Geophys. Res. Lett., 42, 6819–6828,
https://doi.org/10.1002/2015GL064924, 2015.
Williams, A. P., Abatzoglou, J. T., Gershunov, A., Guzman-Morales, J., Bishop, D. A., Balch, J. K., and Lettenmaier, D. P.: Observed Impacts of
Anthropogenic Climate Change on Wildfire in California, Earth's Future, 7,
892–910, https://doi.org/10.1029/2019EF001210, 2019.
Wilson, S. D., Schlaepfer, D. R., Bradford, J. B., Lauenroth, W. K., Duniway, M. C., Hall, S. A., Jamiyansharav, K., Jia, G., Lkhagva, A., Munson, S. M., Pyke, D. A., and Tietjen, B.: Functional Group, Biomass, and Climate Change Effects on Ecological Drought in Semiarid Grasslands, J. Geophys. Res.-Biogeo., 123, 1072–1085, https://doi.org/10.1002/2017JG004173, 2018.
Xiao, M., Koppa, A., Mekonnen, Z., Pagán, B. R., Zhan, S., Cao, Q., Aierken, A., Lee, H., and Lettenmaier, D. P.: How much groundwater did
California's Central Valley lose during the 2012–2016 drought?, Geophys. Res. Lett., 44, 4872–4879, https://doi.org/10.1002/2017GL073333, 2017.
Short summary
Intensified drying of soil and grassland vegetation is raising the impact of fire severity and extent in Southern California. While browned grassland is a common sight during the dry season, this study has shown that there is a pronounced shift in the timing of senescence, due to changing climate conditions favoring milder winter temperatures and increased precipitation variability. Vegetation may be limited in its ability to adapt to these shifts, as drought periods become more frequent.
Intensified drying of soil and grassland vegetation is raising the impact of fire severity and...