Water Chemistry Database

Scope

• 9 sources of environmental data.

• >300,000 rows of chemistry data.

Database Structure

SITESsiteId

site namedepth

countrylatitude & longitude

CHEMISTRYsampleId

siteIddatedepth

salinityTN_N

...

SURFACE DIATOMSsiteId

taxonIdcount

MEANCHEMISTRYsiteId

salinityTN_N

...

SURFACE DIATOMS %siteId

taxonId%

TAXAtaxonIdname

authority

Derived dataMetadata Raw data

2. Are different variables comparable? - TN =f(TDN)?

Environmental data problems

3. Errors and outliers

4. Non-uniform sampling

1. Different variables available - use lowest common denominator?

5. Data not available for entire period required

Raw Secchi Disk depth NJYM3

0

5

10

15

20

25

30

1-Jan-92 1-Jan-93 1-Jan-94 1-Jan-95 1-Jan-96 1-Jan-970

10

20

30

40

Winter Spring Summer Autumn

No. samples by season for SJOSA

mean NOx concentration

Unadjusted 260 g/lSeasonally adjusted 430 g/l

TDN vs TN

R2 = 0.4176

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.30 0.40 0.50 0.60 0.70 0.80 0.90

TN (mg/l)

TD

N (

mg

/l)

0 20 40 60 80

020

4060

80100

120

depth

8 10 12 14

020

4060

80100

temperature

0 10 20 30

010

2030

4050

salinity

0 100 200 300 4000

50100

150

PO4.P

0 200 400 600

050

100150

TP

0 1000 2000 3000 4000 5000

050

100150

NOx.N

0 500 1000 1500 20000

50100

150200

NH4.N

0 1000 2000 3000 4000

020

4060

80100

TN

0 2000 4000 6000

020

4060

80100

SiO3.Si

0 50 100 150

050

100150

chlorophyll.a

0 2 4 6 8 10 12 14

020

4060

secchi

Distribution of variables across all datasets

0.0

0.51.0

1.5

all fi sw dk ho

log

de

pth

0.51.0

1.52.0

2.5all fi sw dk ho

log

PO

4.P

1.52.0

2.5

all fi sw dk ho

log

TP

1.02.0

3.0

all fi sw dk ho

log

NO

x.N

0.51.5

2.5all fi sw dk ho

log

NH

4.N

2.42.8

3.23.6

all fi sw dk ho

log

TN

2.02.5

3.03.5

all fi sw dk ho

log

SiO

3.S

i

0.00.5

1.01.5

2.0

all fi sw dk ho

log

ch

loro

ph

yll.a

-0.50.0

0.51.0

all fi sw dk ho

log

se

cch

i

05

1015

2025

30

all fi sw dk ho

sa

linity

Box plots of variables in datasets

depth

0.85 1.00 1.15 0.5 1.5 2.5 1.0 2.0 3.0 2.4 2.8 3.2 3.6

0.0

1.0

0.8

51

.05

temp

salinity

0.0

1.0

0.5

2.0

PO4

TP

1.5

2.5

1.0

2.5

NOx

NH4

0.5

2.0

2.4

3.0

3.6

TN

0.0 1.0 0.0 1.0 1.5 2.5 0.5 1.5 2.5 0.0 1.0 2.0

0.0

1.5

chla

All datasets

depth

0.88 0.94 1.00 0.8 1.2 1.4 1.8 2.2 2.6 2.4 2.8

0.0

1.0

0.8

80

.96

temp

salinity

0.0

0.8

0.8

1.2 PO4

TP

1.2

1.6

2.0

1.4

2.0

2.6

NOx

NH4

0.5

1.5

2.4

2.8

TN

0.0 1.0 0.0 0.6 1.2 1.2 1.6 2.0 0.5 1.5 0.5 1.0 1.5

0.5

1.5

chla

Sweden

Chemistry Results

Seasonal vs Annual NOx

1

10

100

1000

10000

1 10 100 1000 10000

Annual mean concentation

Sea

son

al m

ean

co

nce

ntr

atio

n

Win

Spr

Sum

Seasonal vs Annual PO4

1

10

100

1000

1 10 100 1000

Annual mean concentration

Sea

son

al m

ean

co

nce

ntr

atio

n

Win

Spr

Sum

Summer NOx depletion Spring/summer PO4x depletion

Conclusions

•Cleaning and normalisation was necessary

• Wide range of environments represented

•Seasonal patterns give insite to processes

•Potential for papers?