Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.153
IF5.153
IF 5-year value: 5.460
IF 5-year
5.460
CiteScore value: 7.8
CiteScore
7.8
SNIP value: 1.623
SNIP1.623
IPP value: 4.91
IPP4.91
SJR value: 2.092
SJR2.092
Scimago H <br class='widget-line-break'>index value: 123
Scimago H
index
123
h5-index value: 65
h5-index65
Preprints
https://doi.org/10.5194/hess-2020-479
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-2020-479
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  29 Sep 2020

29 Sep 2020

Review status
This preprint is currently under review for the journal HESS.

Onset and propagation of drought into soil moisture and vegetation responses during the 2012–2019 drought in Southern California

Maria Magdalena Warter1, Michael Bliss Singer1,2,3, Mark O. Cuthbert1,2,4, Dar Roberts5, Kelly K. Caylor3,5,6, Romy Sabathier1, and John Stella7 Maria Magdalena Warter et al.
  • 1School of Earth and Ocean Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom
  • 2Water Research Institute, Cardiff University, Cardiff, CF10 3AT, United Kingdom
  • 3Earth Research Institute, University of California Santa Barbara, Santa Barbara, CA 93106-3060, USA
  • 4Connected Waters Initiative Research Centre (CWI), School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
  • 5Department of Geography, University of California Santa Barbara, Santa Barbara, CA 93117, USA
  • 6Bren School of Environmental Science and Management, University of California Santa Barbara, Santa Barbara, CA 93117, USA
  • 7Department of Forest and Natural Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA

Abstract. Despite clear signals of regional impacts of the recent severe drought in California within Central Valley groundwater storage and Sierra Nevada forests, our understanding of how this drought affected soil moisture and vegetation responses in lowland grasslands is limited. In order to better understand the resulting vulnerability of these landscapes to fire and ecosystem degradation, we aimed to generalize drought-induced changes in subsurface soil moisture and to explore its effects within grassland ecosystems of Southern California. We used a decadal in situ dataset of high-resolution climate and soil moisture from two grassland sites (coastal and inland), alongside greenness (NDVI) data from Landsat to explore drought dynamics in environments with similar precipitation but contrasting evaporative demand. Analysis of data from 2008 to 2019 showed that the negative impacts of prolonged net precipitation (netP) deficits on vegetation at the inlands site were buffered by fog and moderate temperatures at the coastal site. During the drought, the region experienced an early onset of the dry season, resulting in premature senescence of grasses by mid-April. We developed a parsimonious soil moisture balance model that captures dynamic vegetation–evapotranspiration feedbacks using netP–NDVI relationships as a leading indicator. We then analyzed the links between climate, soil moisture, and vegetation greenness over decadal timescales, exploring the impacts of plausible climate change scenarios that reflect changes to precipitation amounts, their seasonal distribution, and evaporative demand. We found that all scenarios generate early, extreme soil moisture deficits during drought below a vegetation stress threshold, further intensifying early dry season onset and vegetation die-off. These changes suggest potential increases in the risk of wildfires in this and similar regions under climate change, as well as increased grassland ecosystem vulnerability.

Maria Magdalena Warter et al.

Interactive discussion

Status: open (until 24 Nov 2020)
Status: open (until 24 Nov 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Maria Magdalena Warter et al.

Maria Magdalena Warter et al.

Viewed

Total article views: 339 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
262 76 1 339 9 3 3
  • HTML: 262
  • PDF: 76
  • XML: 1
  • Total: 339
  • Supplement: 9
  • BibTeX: 3
  • EndNote: 3
Views and downloads (calculated since 29 Sep 2020)
Cumulative views and downloads (calculated since 29 Sep 2020)

Viewed (geographical distribution)

Total article views: 301 (including HTML, PDF, and XML) Thereof 300 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 26 Oct 2020
Publications Copernicus
Download
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 browning, due to changing climate conditions favoring milder winter temperatures and increased precipitation variability. Vegetation may be limited in their abilities to adapt to these shifts, increasing the risk of widespread wildfires.
Intensified drying of soil and grassland vegetation is raising the impact of fire severity and...
Citation