remediation measures historical changes affecting ......…with contributions anna Åkesson, andrea...
TRANSCRIPT
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Remediation measures of agricultural streams
Anders WörmanThe Royal Institute of Technology, Sweden
…with contributions Anna Åkesson, Andrea Bottacin‐Busolin, Jud Harvey, Andrea Marion, Lars Marklund, Ida Morén, Aaron Packman, Roberto Revelli, Luca Ridolfi, Susa Stonedahl, Joakim Riml.
1. Historical changes in agricultural streams2. Design approach for remediation measures
Nutrient sources
The Baltic Sea
Land‐based remediation actions
1905 1917 1936 1968
1950s
1810s
Historical changes affecting agricultural streams
Drainage works‐ State supported in 1800s‐ Gradual, continuous and
extensive
Hydropower‐ Most watersheds are
affected by regulations
Climate change‐ Fluctuations‐ Global warming
79 selected watersheds
Anna Åkesson, PhD thesis, KTH. 2015.Åkesson et al, 2015, Online in Water Resources Research
Century‐long pattern in daily discharge time‐seriesOnly “sporadic” water quality data is available for the last 50 years
Historical daily, discharge time‐series from 1800s
Unregulated tomoderately regulated
Series ≥ 55 years (median 83 years).
Total coverage 131,000 km2 , 1/3 of Sweden.
Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Pre
cipi
tatio
n (m
3 /s)
0
10
20
30
40
50
60
70
80
90
100
Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Dis
char
ge (m
3 /s)
10
20
30
40
50
60
70
80
90
100
Separating runoff processes and climate
2. Instantaneous unit hydrograph: ‐ Stream network‐ Channel structure‐ Distances‐ Slope
1.Climate
Wörman, et al., 2010. Hydrological ProcessesRiml and Wörman, 2015. Water Resources Research
Q t P(t)ET (t) *
P(t) and ET(t)
3.Discharge
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Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Pre
cipi
tatio
n (m
3 /s)
0
10
20
30
40
50
60
70
80
90
100
Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Dis
char
ge (m
3 /s)
10
20
30
40
50
60
70
80
90
100
Separating runoff processes and climate
2. Instantaneous unit hydrograph: ‐ Stream network‐ Channel structure‐ Distances‐ Slope
Time [days]100 101 102 103
Spe
ctra
l den
sity
10-1
100
101
102
103
Precipitation
Spectrum
, Sp(T)
Period, T (days)
Time [days]100 101 102 103
Spe
ctra
l den
sity
10-1
100
101
102
103
Precipitation
River discharge
Spectrum
, SQ(T)
Period, T (days)
Gap closing with period
1.Climate
SP(T) = a Tb
Steepness depends on runoff processes
Wörman, et al., 2010. Hydrological ProcessesRiml and Wörman, 2015. Water Resources Research
SQ S PET S Runoff scaling function
P(t) and ET(t)
3.Discharge
Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Pre
cipi
tatio
n (m
3 /s)
0
10
20
30
40
50
60
70
80
90
100
Year1933.3 1933.4 1933.5 1933.6 1933.7 1933.8 1933.9
Dis
char
ge (m
3 /s)
10
20
30
40
50
60
70
80
90
100
Separating runoff processes and climate
2. Instantaneous unit hydrograph: ‐ Stream network‐ Channel structure‐ Distances‐ Slope
Time [days]100 101 102 103
Spe
ctra
l den
sity
10-1
100
101
102
103
Precipitation
Spectrum
, Sp(T)
Period, T (days)
Time [days]100 101 102 103
Spe
ctra
l den
sity
10-1
100
101
102
103
Precipitation
River discharge
Spectrum
, SQ(T)
Period, T (days)
Period (days)
Scaling functio
n,
Gap closing with period
Time frame in which runoff processes are important
1.Climate
Time frame in which climate fluctuations are important
SP(T) = a Tb
Steepness depends on runoff processes
Wörman, et al., 2010. Hydrological ProcessesRiml and Wörman, 2015. Water Resources Research
P(t) and ET(t)
3.Discharge
Year1900 1920 1940 1960 1980 2000-1
0
1
2
3
4
5Assmebro Catchment
bP
bQ
1st pol. fit
Period [days]100 101 102
SQ
[m6 ]
10-2
100
102
Decadal average of SQ Assmebro
1933-19421943-19521953-19621963-19721973-19821983-19921993-20022003-2013
Power spectrum for May – Oct period of each year
Non‐changing watershed
Fitted lineSQ(T) = a Tb
Spectral den
sity, S
Q(T)
Slop
e, b
Period (days)
Year Year1900 1920 1940 1960 1980 2000-1
0
1
2
3
4
5Nissafors Catchment
bPbQ1st pol. fit
Period [days]100 101 102
SQ
[m6 ]
10-2
100
102
Decadal average of SQ Nissafors
1933-19421943-19521953-19621963-19721973-19821983-19921993-20022003-2013
Changing watershed
Period (days)
Year
Spectral den
sity, S
Q(T)
Slop
e, b
Discharge
Precipitation
Two similarcatchments.
But different discharge statistics!
Spectral discharge change with landscape changes
Drainage works in agricultural land Changes in discharge spectrum slope
1767 Today
Hydropower regulation
Wörman, Lindström, Åkesson, Riml, 2010. Hydrological Processes
Simulated response using • Hydrodynamical routing• Map studies Gradual changes in discharge
time‐series can be explained by • Stream network topology• Channel morphology
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General trend for increasing discharge powerspectrum slope in the May – Oct period
• More rapid flow changes and increased risk for floods (further downstream)
• Similar pattern for the scaling function : change of the landscape dominates over climate change on time scales
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Calculating hyporheic exchange from measued static head distribution
0.00E+00
2.00E‐04
4.00E‐04
6.00E‐04
8.00E‐04
1.00E‐03
1.20E‐03
1.40E‐03
0 1000 2000 3000 4000 5000 6000
Hydraulic con
ductivity
(m/s)
Longitudinal distance along stream (m)
Depth = 3 cm Depth = 7 cm
Type 1Type 2 Type 3Type 2Type 3
Head variation
Hydraulic conductivity
Tullstorps Brook, Sweden
PG i 2S (i )i4 ∆ i
1 exp 2 2 / i 1 exp 2 2 / i
W 2 PG i
i1
N
K
Decomposition of hyporheic fluxes on wavelengths
Manuscript in prep.See also Wörman et al., Geophysical Research letters (2006, 2007)
Wavelength, (m)
Gradient S
pectrum, P
G
Exchange velocity, W (m/s)
1D gradient spectrum, PG (‐), along stream
= wavelengthS() = Power spectral density of hydraulic headK = Hydraulic conductivity = depth to impermeable surface (or decay parameter)
Hydrostatic vs. hydrodynamic drivers in Tullstops Brook
Longest wavelength considered (m)
Static head driver
Dynamic head driver
Hydrostatic and hydrodynamic drivers can be created in remediation actions
Partitioning of head gradient on drivinga) stream flow, andb) hyporheic flow Riffle‐and‐pool sequence
Balance between preventing floods and purifying stream water
no remediation measure
increased meandering
length=77 mT=4904 sCV(T)=63.1
length=520 mT=855 sCV(T)=19.7
Comparison with results from tracer tests using Rhodamine WT
Tracer injection
Breakthrough curves
sediment trap/pond
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“Acceptable” agreement between predicted and observed values of hyporheic exchange
Verification of bio‐chemical treatment effect remains
Planning Injection liquid
Pumping
Radioisotopes Injection container
Aliquot from injection liquidWaste team
Simultaneous Tracer Test: 3H2O, 15NO3 and 32PO4Not yet evaluated
Conclusions
Gradual increased risk for floods and rapid flow changes during 20th century‐ Gradual smaller proportion of head gradients used for purifying stream water‐ Lesser nutrient retention and decay?
Hydrological changes can be noted in agricultural areas due to drainage works‐ Discharge statistics from mid 1800s ‐ (Limited) map studies and routing analyses
Design approach for estimating hyporheic exchange and treatment effect‐ Static head drivers tend to dominate hyporheic flows‐ Optimization of total head fall for driving the stream and hyporheic flows
Åkesson, A., Peakflow response of stream network, PhD thesis report TRITA‐HYD 2015:2, The Royal Institute of Technology, Stockholm, Sweden.
Åkesson, A., Wörman, A., Riml., J., Seibert, J., 2015. “Change in streamflow response in unregulated catchments in Sweden over the last century”, Online Water Resources Research
Åkesson, A. , Wörman, A., Bottacin‐Busolin, A., 2015. Hydraulic response in flooded stream networks. Water Resources Research, 50, pp. 213‐240, doi: 10.1002/2014WR016279
Boano, F., Harvey, J.W., Marion, A., Packman, A.I., Revelli, R., Ridolfi., L., Wörman, A., 2014. “Hyporheic flow and transport processes: Mechanisms, models, and biogeochemical implications”, Reviews of Geophysics. Volume 52, Issue 4, pages 603–679, December 2014, doi: 10.1002/ 2012RG000417
Morén, I., Riml, J., Wörman, A., 2016. “Design of remediation actions in streams for retention and degradation of nutrients in the hyporheic zone”, Manuscript.
Riml., J., Wörman, A., 2015. “Spatio‐temporal decomposition of solute dispersion in watersheds”, Water Resources Research, DOI: 10.1002/2014WR016385.
Wörman, A., Packman, A.I., Marklund, L., Harvey, J.W., Stone, S., 2006. “Exact three‐dimensional spectral solution to surface‐groundwater interactions with arbitrary surface topography”, Geophys. Res. Lett., 33, L07402, doi:10.1029/2006GL025747.
Wörman, A., A. I. Packman, L. Marklund, J. W. Harvey, and S. H. Stone, 2007. ”Fractal topography and subsurface water flows from fluvial bedforms to the continental shield”, Geophys. Res. Lett.: 34, L07402, doi:10.1029/2007GL029426.
Wörman, A., Lindström, G., Riml., J., Åkesson, A., 2010. “Drifting runoff periodicity during the 20th century due to changing surface water volume”, Hydrological Processes 2010, 24(26), 3772 – 3784, DOI: 10.1002/hyp.7810
This presentation is based on the following publications: