---
OA_type: closed access
_id: '22510'
abstract:
- lang: eng
text: This study advances mechanistic interpretation of predictability challenges
in hydro-geomorphology related to the role of soil moisture spatial variability.
Using model formulations describing the physics of overland flow, variably saturated
subsurface flow, and erosion and sediment transport, this study explores (1) why
a basin with the same mean soil moisture can exhibit distinctly different spatial
moisture distributions, (2) whether these varying distributions lead to non-unique
hydro-geomorphic responses, and (3) what controls non-uniqueness in relation to
the response type. Two sets of numerical experiments are carried out with two
physically-based models, HYDRUS and tRIBS+VEGGIE+FEaST, and their outputs are
analyzed with respect to pre-storm moisture state. The results demonstrate that
distinct spatial moisture distributions for the same mean wetness arise because
near-surface soil moisture dynamics exhibit different degrees of coupling with
deeper-soil moisture and the process of subsurface drainage. The consequences
of such variations are different depending on the type of hydrological response.
Specifically, if the predominant runoff response is of infiltration excess type,
the degree of non-uniqueness is related to the spatial distribution of near-surface
moisture. If runoff is governed by subsurface stormflow, the extent of deep moisture
contributing area and its “readiness to drain” determine the response characteristics.
Because the processes of erosion and sediment transport superimpose additional
controls over factors governing runoff generation and overland flow, non-uniqueness
of the geomorphic response can be highly dampened or enhanced. The explanation
is sediment composed by multi-size particles can alternate states of mobilization
or surface shielding and the transient behavior is inherently intertwined with
the availability of mobile particles. We conclude that complex nonlinear dynamics
of hydro-geomorphic processes are inherent expressions of physical interactions.
As complete knowledge of watershed properties, states, or forcings will always
present the ultimate, if ever resolvable, challenge, deterministic predictability
will remain handicapped. Coupling of uncertainty quantification methods and space-time
physics-based approaches will need to evolve to facilitate mechanistic interpretations
and informed practical applications.
article_processing_charge: No
article_type: original
author:
- first_name: Jongho
full_name: Kim, Jongho
last_name: Kim
- first_name: M. Chase
full_name: Dwelle, M. Chase
last_name: Dwelle
- first_name: Stephanie K.
full_name: Kampf, Stephanie K.
last_name: Kampf
- first_name: Simone
full_name: Fatichi, Simone
id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
last_name: Fatichi
- first_name: Valeriy Y.
full_name: Ivanov, Valeriy Y.
last_name: Ivanov
citation:
ama: Kim J, Dwelle MC, Kampf SK, Fatichi S, Ivanov VY. On the non-uniqueness of
the hydro-geomorphic responses in a zero-order catchment with respect to soil
moisture. Advances in Water Resources. 2016;92:73-89. doi:10.1016/j.advwatres.2016.03.019
apa: Kim, J., Dwelle, M. C., Kampf, S. K., Fatichi, S., & Ivanov, V. Y. (2016).
On the non-uniqueness of the hydro-geomorphic responses in a zero-order catchment
with respect to soil moisture. Advances in Water Resources. Elsevier. https://doi.org/10.1016/j.advwatres.2016.03.019
chicago: Kim, Jongho, M. Chase Dwelle, Stephanie K. Kampf, Simone Fatichi, and Valeriy
Y. Ivanov. “On the Non-Uniqueness of the Hydro-Geomorphic Responses in a Zero-Order
Catchment with Respect to Soil Moisture.” Advances in Water Resources.
Elsevier, 2016. https://doi.org/10.1016/j.advwatres.2016.03.019.
ieee: J. Kim, M. C. Dwelle, S. K. Kampf, S. Fatichi, and V. Y. Ivanov, “On the non-uniqueness
of the hydro-geomorphic responses in a zero-order catchment with respect to soil
moisture,” Advances in Water Resources, vol. 92. Elsevier, pp. 73–89, 2016.
ista: Kim J, Dwelle MC, Kampf SK, Fatichi S, Ivanov VY. 2016. On the non-uniqueness
of the hydro-geomorphic responses in a zero-order catchment with respect to soil
moisture. Advances in Water Resources. 92, 73–89.
mla: Kim, Jongho, et al. “On the Non-Uniqueness of the Hydro-Geomorphic Responses
in a Zero-Order Catchment with Respect to Soil Moisture.” Advances in Water
Resources, vol. 92, Elsevier, 2016, pp. 73–89, doi:10.1016/j.advwatres.2016.03.019.
short: J. Kim, M.C. Dwelle, S.K. Kampf, S. Fatichi, V.Y. Ivanov, Advances in Water
Resources 92 (2016) 73–89.
das_tickbox: '1'
date_created: 2026-07-27T12:30:24Z
date_published: 2016-07-01T00:00:00Z
date_updated: 2026-08-06T07:50:36Z
day: '01'
doi: 10.1016/j.advwatres.2016.03.019
extern: '1'
intvolume: ' 92'
keyword:
- Soil moisture
- Spatial heterogeneity
- Hydrological response
- Geomorphic response
- Non-uniqueness
- Hydraulic connectivity
language:
- iso: eng
month: '07'
oa_version: None
page: 73-89
publication: Advances in Water Resources
publication_identifier:
issn:
- 0309-1708
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: On the non-uniqueness of the hydro-geomorphic responses in a zero-order catchment
with respect to soil moisture
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 92
year: '2016'
...
---
OA_place: publisher
OA_type: free access
_id: '22536'
abstract:
- lang: eng
text: Increasing concentrations of atmospheric carbon dioxide are expected to affect
carbon assimilation and evapotranspiration (ET), ultimately driving changes in
plant growth, hydrology, and the global carbon balance. Direct leaf biochemical
effects have been widely investigated, whereas indirect effects, although documented,
elude explicit quantification in experiments. Here, we used a mechanistic model
to investigate the relative contributions of direct (through carbon assimilation)
and indirect (via soil moisture savings due to stomatal closure, and changes in
leaf area index) effects of elevated CO2 across a variety of ecosystems. We specifically
determined which ecosystems and climatic conditions maximize the indirect effects
of elevated CO2. The simulations suggest that the indirect effects of elevated
CO2 on net primary productivity are large and variable, ranging from less than
10% to more than 100% of the size of direct effects. For ET, indirect effects
were, on average, 65% of the size of direct effects. Indirect effects tended to
be considerably larger in water-limited ecosystems. As a consequence, the total
CO2 effect had a significant, inverse relationship with the wetness index and
was directly related to vapor pressure deficit. These results have major implications
for our understanding of the CO2 response of ecosystems and for global projections
of CO2 fertilization, because, although direct effects are typically understood
and easily reproducible in models, simulations of indirect effects are far more
challenging and difficult to constrain. Our findings also provide an explanation
for the discrepancies between experiments in the total CO2 effect on net primary
productivity.
article_processing_charge: No
article_type: original
author:
- first_name: Simone
full_name: Fatichi, Simone
id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
last_name: Fatichi
- first_name: Sebastian
full_name: Leuzinger, Sebastian
last_name: Leuzinger
- first_name: Athanasios
full_name: Paschalis, Athanasios
last_name: Paschalis
- first_name: J. Adam
full_name: Langley, J. Adam
last_name: Langley
- first_name: Alicia
full_name: Donnellan Barraclough, Alicia
last_name: Donnellan Barraclough
- first_name: Mark J.
full_name: Hovenden, Mark J.
last_name: Hovenden
citation:
ama: Fatichi S, Leuzinger S, Paschalis A, Langley JA, Donnellan Barraclough A, Hovenden
MJ. Partitioning direct and indirect effects reveals the response of water-limited
ecosystems to elevated CO. Proceedings of the National Academy of Sciences.
2016;113(45):12757-12762. doi:10.1073/pnas.1605036113
apa: Fatichi, S., Leuzinger, S., Paschalis, A., Langley, J. A., Donnellan Barraclough,
A., & Hovenden, M. J. (2016). Partitioning direct and indirect effects reveals
the response of water-limited ecosystems to elevated CO. Proceedings of the
National Academy of Sciences. National Academy of Sciences. https://doi.org/10.1073/pnas.1605036113
chicago: Fatichi, Simone, Sebastian Leuzinger, Athanasios Paschalis, J. Adam Langley,
Alicia Donnellan Barraclough, and Mark J. Hovenden. “Partitioning Direct and Indirect
Effects Reveals the Response of Water-Limited Ecosystems to Elevated CO.” Proceedings
of the National Academy of Sciences. National Academy of Sciences, 2016. https://doi.org/10.1073/pnas.1605036113.
ieee: S. Fatichi, S. Leuzinger, A. Paschalis, J. A. Langley, A. Donnellan Barraclough,
and M. J. Hovenden, “Partitioning direct and indirect effects reveals the response
of water-limited ecosystems to elevated CO,” Proceedings of the National Academy
of Sciences, vol. 113, no. 45. National Academy of Sciences, pp. 12757–12762,
2016.
ista: Fatichi S, Leuzinger S, Paschalis A, Langley JA, Donnellan Barraclough A,
Hovenden MJ. 2016. Partitioning direct and indirect effects reveals the response
of water-limited ecosystems to elevated CO. Proceedings of the National Academy
of Sciences. 113(45), 12757–12762.
mla: Fatichi, Simone, et al. “Partitioning Direct and Indirect Effects Reveals the
Response of Water-Limited Ecosystems to Elevated CO.” Proceedings of the National
Academy of Sciences, vol. 113, no. 45, National Academy of Sciences, 2016,
pp. 12757–62, doi:10.1073/pnas.1605036113.
short: S. Fatichi, S. Leuzinger, A. Paschalis, J.A. Langley, A. Donnellan Barraclough,
M.J. Hovenden, Proceedings of the National Academy of Sciences 113 (2016) 12757–12762.
das_tickbox: '1'
date_created: 2026-07-27T12:30:24Z
date_published: 2016-11-08T00:00:00Z
date_updated: 2026-08-06T08:08:46Z
day: '08'
doi: 10.1073/pnas.1605036113
extern: '1'
external_id:
pmid:
- '27791074'
intvolume: ' 113'
issue: '45'
keyword:
- carbon dioxide
- modeling
- FACE
- soil moisture
- evapotranspiration
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1073/pnas.1605036113
month: '11'
oa: 1
oa_version: Published Version
page: 12757-12762
pmid: 1
publication: Proceedings of the National Academy of Sciences
publication_identifier:
eissn:
- 1091-6490
issn:
- 0027-8424
publication_status: published
publisher: National Academy of Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: Partitioning direct and indirect effects reveals the response of water-limited
ecosystems to elevated CO
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 113
year: '2016'
...