Durov Diagram

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Griffy Reservoir Water Sampling Locations
7
6
Griffy
Lake
3
4
5
10
1
2
9
University
Lake
Sample Locality
Note: Sites 9 and 10 were added in 2011. (Site 3 was dry due to low water level)
Griffy Field Teams and Water Sample IDs
Data Analysis
and Presentation (2010)
Temp
pH
(oC)
SpC
Redox
(µS/cm) (mV)
DO
Alkalinity
F-
Cl-
NO2-
Br-
NO3- PO43- SO42-
Ca2+
Mg2+
Na+
K+
(mg/L) (mg/L) (mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L) (mg/L) (mg/L) (mg/L) (mg/L)
GRIFFY LAKE –
7 Sept 2010
Boat House Dock B1 23.0 7.94
590
141.1
165.9 0.12 49.4
0.94 1.21 18.18 35.07 12.58 38.25 11.35
0.12 22.7
1.48 1.72 1.80 11.04 41.14 11.90 34.75 11.48
159.3 0.28 46.5
0.91 1.16 18.37 58.02 20.52 24.30 2.07
Boat House Dock #2
inlet sample 1 - JB 22.0 8.10
556
4.4
Inlet sample 1 group A
0.10 54.4
0.03 0.04
16.55 50.50 9.03 13.60 1.88
Inlet Group A
0.01 75.0
0.15
13.28 14.39 5.39 17.65 1.45
91.8 0.02 0.13 0.10
10.24 14.62 5.39 16.50 1.91
"Pond" group A 30.4 7.89
215
16.9
Causeway Group 2 B 25.0 6.71
637
120.0
Causeway 2 25.0 6.96
530
155.6
8.5
54.2
148.6 0.04 63.2
0.24 0.33 0.51 32.27 36.42 9.02 26.60 4.50
0.09 55.1
0.17 0.23 0.30 30.94 42.85 10.24 30.50 5.99
The Milliequivalent (meq/l),
Units of Equivalent Weight
An equivalent is the amount of an anion or cation species needed
to add or remove one mole of electrons from a system.
A milliequivalent is defined as 1/1000 of an
equivalent of a chemical element, radical or
compound. Its abbreviation is "mEq" or "meq".
Concentration in mg/L * valence
Concentration in meq/l = ----------------------------------------------F.W. of the ion
•Milliequivalents can be expressed in milligram units (mg). To
convert grams to milligrams, multiply the value by 1,000.
•Milliequivalents can be calculated using millimoles (mmol). The
equation to calculate mEq from mmol is mEq = mmol x V. In this
case, the unit of measurement is millimole (mmol), not grams.
Converting Ionic Concentrations to
Units of Equivalent Weight (meq/l)
Concentration in mg/L * valence
Concentration in meq/l = ----------------------------------------------F.W. of the ion
Ion
Conc.
(mg/l)
Valence
F.W.
Conc.
(meq/l)
Ca+2
151
+2
40.08
7.53
Mg+2
23
+2
24.31
1.90
Na+1
165
+1
22.99
7.18
19
+1
39.10
0.49
Total meq/l cations:
17.10
K+1
HCO3-1
SO4-2
Cl-1
401
-1
61.02
6.57
58
-2
96.06
1.21
345
-1
35.45
9.73
Total meq/l anions:
17.51
EMP balances:
Total meq/l cations: 17.10 meq/l
difference = 2.39%
Total meq/l anions: 17.51 meq/l
difference = 2.42%
Difference: 0.41 meq/l
•An acceptable analyses will have a %-difference that is less than 10%
Though, less than 5% is best.
Indicates you have accounted for all the major ions in the system and
have a “complete” analysis.
If balance is off, not accounting for an ion such as Fe, Si, Al, or OH,
incorrect dilutions,
very dilute samples,
math errors,
contamination
Stiff Diagram
Stiff diagrams are graphical representation of
water chemical analyses, first developed by H.A.
Stiff in 1951.
Stiff Diagram –sample 3A
Mg
A polygonal shape is created from three or four
parallel horizontal axes extending on either side of
a vertical zero axis. Cations are plotted in
milliequivalents per liter on the left side of the
zero axis, one to each horizontal axis, and anions
are plotted on the right side. Stiff patterns are
useful in making a rapid visual comparison
between water from different sources.
ADVANTAGES
• Can help visualize ionically related waters from
which a flow path can be determined, or;
• If the flow path is known, to show how the
ionic composition of a water body changes
over space and/or time.
DISADVANTAGE
• Only one analysis per plot.
SO4
Ca
HCO3
Na
Cl
0
Other possible pairs:
Fe
NO3
K
NO3
Fe
CO3
Application of Stiff Diagrams
A.
Figure 7. Stiff diagrams for samples from the
Queen City and Sparta Aquifer Systems
Abbott, M., 2008, Final Report: Evaluation Groundwater
Chemistry in Gonzales County, Texas and Technical and
Educational Assistance to Groundwater Conservation
Districts in Texas: US EPA .
B.
Figure 5. Stiff diagrams annotated on an engineering
plan map of Horsetooth Dam that show different
chemistry (polygon shapes) for each piezometer
located in the embankment and alluvium.
Craft, D., 1999, Summary and Interpretation of Chemistry
Data for Reservoir, Seeps, and Groundwater from
Horsetooth Dam, Colorado-Big Thompson Project, Ft.
Collins, Colorado, Technical Memorandum D-8290/99001, U.S. Bureau of Reclamation, Dam Safety Office,
Denver, Colorado.
Abbott, M., 2008, Final Report: Evaluation Groundwater
Chemistry in Gonzales County, Texas. EPA Report
Horsetooth Dam, Colorado-Big Thompson Project, Ft. Collins, Colorado
Craft, 1999.
Piper Diagram
A piper diagram is a graphical
representation of the chemistry of a
water sample or samples.
The cations and anions are shown by
separate ternary plots.
The apexes of the cation plot are
calcium, magnesium and sodium
plus potassium cations. The apexes
of the anion plot are sulfate,
chloride and carbonate plus
bicarbonate anions.
The two ternary plots are then
projected up onto a diamond. The
diamond is a matrix transformation
of a graph of the anions and cations.
In Piper diagrams the concentrations
are expressed as %meq/L.
Figure 1-7 from Kehew (2001). Classification of
hydrochemical facies using the Piper plot.
% meq/l
Ion
Conc.
(mg/l)
Valence
F.W.
Conc.
(meq/l)
(% meq/l)
Ca+2
151
+2
40.08
7.53
44.34
Mg+2
23
+2
24.31
1.90
11.21
Na+1
165
+1
22.99
7.18
41.99
19
+1
39.10
0.49
2.46
Total meq/l cations:
17.10
100
K+1
HCO3-1
SO4-2
Cl-1
401
-1
61.02
6.57
37.52
58
-2
96.06
1.21
6.91
345
-1
35.45
9.73
55.57
Total meq/l anions:
17.51
100
Cations
Ion
Conc.
(mg/l)
Valence
F.W.
Conc.
(meq/l)
(% meq/l)
Ca+2
151
+2
40.08
7.53
44.34
Mg+2
23
+2
24.31
1.90
11.21
Na+1
165
+1
22.99
7.18
41.99
19
+1
39.10
0.49
2.46
K+1
Anions
Ion
HCO3-1
SO4-2
Cl-1
Conc.
(mg/l)
Valence
F.W.
Conc.
(meq/l)
(% meq/l)
401
-1
61.02
6.57
37.52
58
-2
96.06
1.21
6.91
345
-1
35.45
9.73
55.57
Projection
into the
upper
diamondshaped field
ADVANTAGES
• Many water analyses can be
plotted on the same diagram.
• Can be used to classify waters
by hydrochemical facies.
• Can be used to identify mixing
of waters.
• Can track changes through
space and temporal
relationships.
DISADVANTAGES
• Concentrations are
renormalized.
• Cannot easily accommodate
waters where other cations or
anions may be significant.
Figure 1-7 from Kehew (2001). Classification of
hydrochemical facies using the Piper plot.
A.
Application of
Piper Diagrams
B.
Figure 3: Piper diagram (Piper, 1944) showing regional
mixing trends. Fields show localized well-defined
regional and subregional mixing trends. Important endmember compositions and high-volume springs of the
Colorado Plateau region.
Crossey, LJ, Karlstrom, KE, Springer, AE, Newell, D, Hilton, DR,
Fischer, T, 2009, Degassing of mantle-derived CO2 and He from
springs in the southern Colorado Plateau region—Neotectonic
connections and implications for groundwater systems
Geological Society of America Bulletin, 121:1034-1053.
Figure 2: Piper plot of historical background
(letters) and site (numbers) water quality
analysis.
.McLin, SG, 1986, Evaluation of Aquifer
Contamination from Salt Water Disposal Wells:
Proceedings of the Oklahoma Academy of
Science, 66: 53-61.
Durov Diagram
• Primary: Cations (i.e. Na + K, Ca and Mg) and Anions (i.e. Cl,
HCO3 and SO4), and total cations vs. total anions only.
Data points
• Expanded: TDS and pH added
Anions
TDS (mg/L)
(norm)
Cations Total Cations
(norm)
pH
vs.
Total Anions
Source: RockWare Inc.,
http://www.rockware.com/product/gallery.php?id=150
Durov Diagram
Description/ Type of data : a composite plot consisting of 2 ternary diagrams where the
cations of interest are plotted against the anions of interest (data is normalized to 100%);
sides form a binary plot of total cation vs. total anion concentrations (this plot can be
contoured); expanded version includes TDS (mg/L) and pH data added to the sides of the
binary plot to allow further comparisons.
Use: to graphically illustrate cation/anion concentrations, relative to TDS and pH.
– For example, using Griffy Lake samples IC and AAS data, we can plot the ion
concentrations, then calculate the TDS from our specific conductivity field
measurements, and use the pH field measurements. Because we sampled at several
locations (i.e. causeway, pond, etc.), we can use those as data groups to see if there are
any spatial variations in water chemistry , and if so, could they be related to a different
TDS content, different pH, or both.
Example case studies:
– Vermeulen, P., and Usher, B., 2009, The effect of graben structures on the migration of
groundwater contaminants at an industrial site: Environmental Geology, 58:739-749.
• Different water chemistry in aquifers on the opposite sides of graben structures
– Petalas, C.P., and Diamantis, I.B., 1999, Origin and distribution of saline groundwaters in
the upper Miocene aquifer system, coastal Rhodope area, northeastern Greece:
Hydrogeology Journal, 7:305-316.
• Variations in ionic compositions of saline vs. fresh water
Durov Diagrams
The intersection of lines
extended from the two sample
points on the triangle to the
central rectangle gives a point
that represents the major-ion
compositions on a percentage
basis. From this point, lines
extending to the adjacent scaled
rectangles provide for
representations of the analyses
in terms of two parameters
selected from various
possibilities, such as total majorion concentrations, total
dissolved solids, ionic strength,
specific conductance, hardness,
total dissolved inorganic carbon,
or pH.
Durov SA, 1948, Natural waters and graphic representation of
their compositions. Dokl Akad Nauk SSSR 59:87–90.
Expanded Durov Diagram
cations
anions
D. K. Chadha, 1999, A proposed new diagram for geochemical classification of natural
waters and interpretation of chemical data: Hydrogeology Journal 7:431–439.
Schoeller Diagram
A Schoeller Diagram is a semi-logarithmic diagram of the concentrations of
the main ionic constituents in water (SO4, HCO3, Cl, Mg, Ca, Na/K) in
equivalents per million per kg of solution (mEq/kg).
• An equivalent is the amount of an anion or cation species needed to add or remove one
mole of electrons from a system.
• Concentrations of each ion in each sample are represented by points on six equally
spaced lines and points are connected by a line.
• The diagram gives absolute concentration, but the line also gives the ratio between
two ions in the same sample
•
If a line joining two points representing ionic concentrations in a single sample is parallel
to another line joining a second set of concentrations from another sample, the ratio of
those ions in those samples are equal.
Converting data in mg/L to milliequivalents:
•
Multiply mg/L by one over the milliequivalent weight
(which can be looked up in tables).
• This gives mEq/L, using mg/kg will yield mEq/kg
•
Milliequivalent weight= (atomic weight)/(valence state
x 1000)
Schoeller Diagram
Studies that utilize Schoeller diagrams :
• Chemical quality of waters
• Groundwater/Surface water studies, hydrology in general
• Waste Water potentially from any Economic Geology related Industry (oil, mining,
etc) or runoff from agriculture
• Mineral exploration
• Barbiéro, L., et al. Geochemistry of water and ground water in the
Nhecolândia, Pantanal of Mato Grosso, Brazil: variability and
associated processes. Wetlands, v. 22, no. 3 (2002), pp. 528-540.
•
Investigated possibility that saline and freshwater lakes in Pantanal remain
connected by a sub-surface aquifer.
• Van Voast, Wayne A. Geochemical signature of formation waters
associated with coalbed methane. American Association of
Petroleum Geologists (AAPG) Bulletin, v. 87, no. 4 (April 2003), pp.
667–676.
•
Described typical chemistry of water associated with coalbed methane that can
be an exploration tool, regardless of formation lithology or age.
• Hill, C. Geology of Carlsbad Cavern and other caves in the Guadalupe
Mountains, New Mexico, and Texas. New Mexico Bureau of Mines &
Mineral Resources Bulletin 117 (1987).
• Huizar A., et al. (1998) 'Patterns of groundwater hydrochemistry in
Apan-Tochac sub-basin, Mexico / Hydrochimie des eaux souterraines
du sous-bassin Apan-Tochac, Mexique'. Hydrological Sciences Journal,
43: 5, 669 - 685.
Figure 5 (Barbiero et al 2002). Schoeller diagram of three
representative fresh (a) and concentrated (b) waters. 1:
Corixo; 2: Negro River; 3: Lagoa; 4 and 5: Water table in
cordilheira; 6: Salina.
[semi-logarithmic axis]
Schoeller Diagram
cations
anions
Radial Plot
What is a radial plot?
• A radial plot is a diagram
used to compare samples or
values against each other,
according to a standard
measurement.
• The circular plot type allows
you to easily see how values
compare based on the
shape of each section of
plot.
What type of data is used?
• In this plot, the data shows
milliequivalents/kilogram
(meq/l) for various ions and
compounds.
Radial Plot
What kinds of studies?
• Studies that involve direct
comparisons:
–
–
–
–
–
Examples
•
Mixing phase of sea water and fresh
water
•
Wind direction and frequency
Ionic concentrations
Wind speed and velocity
Seasonal plant productivity
Fission track dating
Mineral availability
Example citations:
• Escolero. et all. Geochemistry of the Hydrogeological
Reserve of Meridia, Yucatan, Mexico. Universidad
Nacional Autonoma de Mexico. 2005.
• Garcia et all. Effects of Wind on Background Particle
Concentrations at Truck Freight Terminals. J Occup
Environ Hyg. 2007.
Time Series - pH
Plot description
This plot describes the relationship between pH values and dates between Aug 3rd and
Aug 25th in 2003. The pH values were kind of scattered, ranging from 6.75 to 7.05, with
an average of 6.9. The pH kept increasing for the first six days and arrived at the highest
value (7.05) on Aug 7th and Aug 8th, followed by a continuous decrease until Aug 11th.
On Aug 13th, the pH values rose again and stayed at 6.95 for the following 7 days. The
pH then declined and went through several fluctuations and reached the lowest value on
Aug 24th.
Type of data
The data used in the plot was the directly measured pH without any transformation.
Many other characteristic parameters, such as temperature, conductivity, alkalinity and
so on, can also be plot as functions of time series. This plot is probably the
environmental monitoring result of the pH variation in a river, a lake or a wastewater
discharge outlet.
Time Series - pH
•Types of studies in which pH, or other similar data, is examined over time
•Evaluating ocean acidification
•Effects of rising sea surface temperature on pH through time
•Carbonate concentrations
•Monitoring seasonal cycles that affect pH, pCO2, and salinity
•Buffering capacity of a system through time
•Also used frequently in fields outside of water chemistry
•Economics (ie the stock market)
•Quantum physics
•Mortality rates
•Population studies
Specific Studies
• R. A. Quick and A. E. Ogden, Hydrochemistry as a means of
Delineating Groundwater flow patterns in the Edward’s Aquifer,
San Marcos, Texas, U.S.A.
•Researchers plotted pH, temperature, dissolved
oxygen, discharge, sulfate, and conductance, over
the twelve month duration of their study to
determine the parameters of a series of aquifer
springs. The study was aimed at investigating the
validity of a model that suggested the spring would
cease to flow in 2020. In this process, researchers
discovered that there are actually two chemically
unique groups of springs and that discharge had a
more profound role in altering water chemistry for
one group as opposed to the other.
•Bredemeier, Dohrenbusch, and Murach, Response of soil water
chemistry and fine-roots to clean rain in a spruce forest ecosystem
at Solling, FRG
•In the Solling experimental forest in central
Germany a clean rain roof experiment is conducted
in a 60 year old Norway Spruce (Picea abies KARST.)
stand. In this experiment with application of
artificially prepared pre-industrial throughfall there
is now a time series of soil water chemistry data
from about 2 yr of pre-experiment and 3.5 yr of
manipulation treatment.
Time Series
Variable
Time Series
Time
[ Julian days, calendar dates, hours, minutes, seconds, years, decades, etc.]
Box and Whisker plot
• Box and Whisker is a summary plot of 5 statistics: minimum, maximum,
median and the lower and upper quartiles. Mean is sometimes shown as well.
• Multiples plots can be connected to show the variance of data over time or
compared to other sites to show differences.
Box and Whisker Plot
• It is often used in Environmental Chemistry to show
water quality variance over time, between areas, and
in concentration studies.
– Allows comparison range, median, spread, etc more
conclusion can be drawn than from a time plot
• Examples
– Knudson, A.C., M.E. Gunter, 2002, Sedimentary Phosphorites—An
Example: Phosphoria Formation, Southeastern Idaho, U.S.A.: Reviews in
Mineralogy and Geochemistry, v. 48, no. 1, p. 363-389.
– Lmeida, C.A., et al., 2010, Mineral Paragenesis , Alteration , and
Geochemistry of the Two Types of Gold Ore and the Host Rocks from the
Carlin-Type Deposits in the Southern Part of the Goldstrike Property ,
Northern Nevada: Implications for Sources of Ore-Forming Elements , Ore
Geologic Society, v. 105, no. 1, p. 971-1004.
Box and Whisker Plot
combined in a Time Series Plot
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