debra s. baker and donald g. huggins
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Debra S. Baker and Donald G. HugginsDebra S. Baker and Donald G. Huggins
CC
P B
Central Plains Center for BioAssessmentKansas Biological Survey, University of Kansas
Nutrient Trends in Reference Nutrient Trends in Reference Streams of the Central PlainsStreams of the Central Plains
30th Annual Great Plains Limnology Conference, Lincoln, NE, 10 – 11 October 2003
Nutrients in Streams• Clean Water Action Plan 1998 - USEPA initiative to
establish regionally-based nutrient criteria for waterbodies via Regional Technical Assistance Groups (RTAGs).
• Develop a dataset of nutrient levels found in “reference” or least impacted streams of USEPA Region 7.
• Should criteria be single values for the entire EPA Region, or should criteria be based on a subset of stream characteristics, such as ecoregion?
Stream Sites
Parameters• in situ:
DO, turbidity, pH, conductivity
• Lab analysis:
TN, NH4-N, NO3-N,
TP, PO4-P,
chlorophyll a, phaeophytin a
Hypothesis• Streams will show affiliations based on some suite of
water quality characteristics (e.g. nutrient concentrations).
• Principal Components Analysis (PCA) was used to determine probable relationships among the parameters.
• Resulting factor scores were used as input for clustering analyses to identify stream groupings and compare resulting spatial differences to ecoregions.
Analyses
Resulting Dataset
• May 1999 – June 2002
• 94 streams, 522 records, taken at base flow
• TN: 5 – 20410 g/l; Median: 1180 g/l• TP: 2.5 – 1320 g/l; Median: 86 g/l• Chlorophyll a: 0.5 – 216 g/l; Median: 4 g/l
PCA Analysis
• Factor 1 TP, PO4-P
• Factor 2 TN, NO3-N
• Factor 3 chlorophyll a, phaeophytin a
• Factor 4 pH, DO
• Factor 5 conductivity
• Factor 6 NH4-N
• Calculated medians of the 6 PCA factor scores for each of the 94 sites.
• K-means cluster analysis on all PCA factors – resulted in 6 clusters.
• K-means cluster analysis on just the nutrient factors – resulted in 6 clusters.
K-means Cluster Analysis
Clustering on All Factors
Clustering on Nutrient Factors
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
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1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
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250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
N & P Factors
-3
-1
0
1
2
-3 -1 0 1 2high nitrogen factor 2 low
hig
h
ph
osp
ho
rus
fact
or
1
lo
w
cluster
123456
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
clusters
med
ian
TN
ug
/l
0
50
100
150
200
250
med
ian
TP
ug
/l
TN
TP
0
1000
2000
3000
4000
5000
6000
CG
P
CIP
CO
T DA FH IRL
MA
P
NG
L
NG
P
NSH O
H
ST
WC
B
WH
P
Ecoregions
med
ian
TN u
g/l
0
50
100
150
200
250
med
ian
TP u
g/l
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6
Clusters
med
ian
TN u
g/l
0
50
100
150
200
250
med
ian
TP u
g/l
TN
TP
0
1000
2000
3000
4000
5000
6000
CG
P
CIP
CO
T
DA FH
IRL
MA
P
NG
L
NG
P
NS
H
OH
ST
WC
B
WH
P
med
ian
TN
ug
/l
TN nonref
TN ref
0
50
100
150
200
250
300
350
CG
P
CIP
CO
T
DA
FH
IRL
MA
P
NG
L
NG
P
NS
H
OH ST
WC
B
WH
P
med
ian
TP
ug
/l
TP nonref
TP ref
Conclusions
• Nutrient levels varied by ecoregion.
• Streams that we clustered by nutrient factors and independently of ecoregion showed ecoregional affiliations.
Future Study
• Seasonal influences
• Chlorophyll a
• USEPA Region7 Nutrient RTAG
• Macroinvertebrates
• Watershed and land use
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