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A Hydrological Framework for Biogeochemical Studies
Helmut Elsenbeer1 and Jorge Marcos de Moraes2
1Institute of Geoecology, University of Potsdam, Germany
2CENA/Universidade de São Paulo, Piracicaba, Brazil
The archetypal nutrient cycling scenery
The link between hydrological pathways and nutrient flow
The risk of ignoring hydrology in biogeochemical studies
Hydrological flowpaths as we know them
Get to know your catchment: tools for a rapid hydrologic appraisal
Overview
The Archetypal Scenery:Ecosystem Fluxes and Stores of Nitrogen (N) and Potassium (K)
Precipitation
Streamflow
Litter fallThroughfall
Forest floor
Shallow soil water
Deep soil water
N K
N K
The Archetypal Scenery:Ecosystem Fluxes of Dissolved Nitrogen (N) and Potassium (K)
Precipitation
Streamflow
Throughfall
Forest floor
Shallow soil water
Deep soil water
N K
N K
Litter fall
Precipitation
Deep percolation
Lateral, near-surface flowpaths
Possible Hydrological Flowpaths
Precipitation
Lateral, near-surface flowpaths
Precipitation
Streamflow
Throughfall
Shallow soil water
Deep soil water
The Archetypal Scenery Meets Hydrology
Deep percolation
Near-Surface Lateral Flow
NO3-, DOC, K >> Si, Ca, Na
Deep Lateral Flow
Si, Ca, Na >> NO3-, DOC, K
Flowpaths and Water Chemistry
0 20 40 60 80 100 120
Precipitation
Throughfall
Soil water, 30 cm
Soil water, 60 cm
Soil water, 90 cm
Riparian zone
Groundwater
Baseflow
K (µmol/L))
The Watershed Chemistry of PotassiumIgnoring Hydrologic Pathways (Assuming Verticality)
Precipitation
Throughfall
0 20 40 60 80 100 120
Soil water, 30 cm
Soil water, 60 cm
Soil water, 90 cm
Riparian zone
Groundwater
Baseflow
K (µmol/L))
Overland flow
Return flow
Pipeflow
The Watershed Chemistry of PotassiumTaking into Account Hydrologic Pathways
K/S
iO2
(mo
lar
rati
o)
1 2 3 4 5
Dis
char
ge
(L/s
)
0
2
4
6
0.0
0.4
0.8
1.2
1.6
2.0
2.4DischargeChemograph
Overland flow
Return flow
Stormflow Hydrograph and Chemograph
Time (h)
1 2 3 4 5
Time (h)
0
2
4
6
10
20
30
40
50
DischargeChemograph
Overland flow
Return flow
Ca
(µm
ol/
L)
Stormflow Hydrograph and ChemographD
isch
arg
e (L
/s)
Soil water
Discharge
Solute Signal
Overland flow
Through-flow
Sources Stream response Flowpaths
Throughfall
Groundwater
Interpreting the Solute Signal: Where do the Nutrients Come From?
Central Amazônia
PanamaPeruvian AmazonQueenslandRondônia
PanamaRondônia
PeninsularMalaysia
Central Amazônia
Lateral Hydrological Flowpaths in Rainforest Ecosystems
Paragominas
Flowpathhydrographs
Hydrochemistry
InfiltrabilityPermeability changes
with depth
Soil water orgroundwater
energy status
Rainfall intensities,amount, and frequency
Saturation deficitSoil moisture status
Level 1
Level 2
Level 3
Level 4
A Hierarchical Approach to Understanding Hydrochemical Flowpaths
Level 1
Level 2
Level 3
Level 4
Flowpathhydrographs
InfiltrabilityPermeability changes
with depth
Soil water orgroundwater
energy status
Rainfall intensities,amount, and frequency
Saturation deficitSoil moisture status
Hydrochemistry
Top Level Information on Shaky Ground
Level 1
Level 2
Level 3
Level 4
InfiltrabilityPermeability changes
with depth
Rainfall intensities,amount, and frequency
Hydrochemistry
Flowpathhydrographs
Saturation deficitSoil moisture status
Soil water orgroundwater
energy status
Bottom Level InformationSolid Basis for Bottom-Up Inference
Level 2
Level 3
Level 4
Flowpathhydrographs
Saturation deficitSoil moisture status
Soil water orgroundwater
energy status
Hydrochemistry
InfiltrabilityPermeability changes
with depth
Rainfall intensities,amount, and frequency
Level 1
Mid-Level InformationWeak Explanatory Basis
Precipitation
Deep percolation
Lateral, near-surface flowpaths
Possible Hydrological Flowpaths
Overland flow
Water-level recorder
ISCO sampler
Venturi flume
Flowpathhydrographs
Hydrochemistry
InfiltrabilityPermeability changes
with depth
Soil water orgroundwater
energy status
Rainfall intensities,amount, and frequency
Saturation deficitSoil moisture status
Level 1
Level 2
Level 3
Level 4
A Hierarchical Approach to Understanding Hydrochemical Flowpaths
