Bayerisches Landesamt fürUmwelt
WEB MAP SERVICE FOR INORGANIC BACKGROUND VALUES OF GROUNDWATER IN GERMANYB. Wagner, T. Walter
Bayerisches Landesamt fürUmwelt
Groundwater chemistry as a result of interacting factors: influences from the surface
underground processes
airpollution
temperature rainfall
weathering mixingprocesses
GW-recharge mining
lithology
land-use
pointsources
chemical composition of groundwater
anthropogene Faktoren
Grundwasserentnahme
groundwater usage
natürliche Faktoren
hydraulic properties
Aquifer-Typus
climate
groundwater abstraction
atmospheric deposition
Ore
bodi
es
geology
natural factors anthropogenic factors
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
Conceptual model of parameter distribution
factors influencing groundwater chemistry have different ranges and intensities in time and space:
widespread, natural longterm factors will produce a stable equilibrium with definite statistical parameters
Short term anthropogenic influences will act on a more local scale and at a different range of values, natural mineralisations are also limited in space
BACKGROUND
ANOMALY
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
Overlapping of a normal and an anomalous distribution
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
histogram and probability plot:
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
The probability plot as diagnostic and statistical tool
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
Treatment of censored data
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
Treatment of values below detection level:0,5% 2,5% 10% 25% 50% 75% 90% 97,5% 99,5%
0,8
1,81,829818802
0,1664171550,1
1
10
100
-3 -2 -1 0 1 2 3
Kupf
er C
u [µ
g/l]
standard deviations from meanupper anomaly normal population lower cut-off valueupper cut-off value 10th and 90th percentiles confidence limits 90%trend normal population
95%: 2,46
90%: 1,83
0%
10%
20%
30%
0,1 1 10 100
empirical distribution of data fitted distribution
Range of data < d.l.
Detection level
Detectionlevel
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201010
Project goals and concept
• Working group "Background values of groundwater":launched by the Geological Surveys of Germany within the context of the EG-Water Framework Directive
• Goal: determine background values of groundwater in Germanyand illustrate them in a map
• Reference: upper aquifer
• Data basis: abt. 48.000 groundwater measuring points
• Parameters: anorganic major and trace elementsphysicochemical parameters
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201011
Parameters
Major elements: Ca, K, Mg, Na, HCO3, SO4, Cl
Trace elements: Br, F, PO4, SIO2, Fe, Mn, Ba, Sr
Ag, Al, As, B, Bi, Cd, Co, Cr, Cu, Hg, Li, Mo, Ni, Pb, Sb, Se, Sn, T, Tl, U, V, Zn
Physicochemical parameters: electrical conductivity, pH
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201012
Definition background value
Background value: the upper margin of the concentration of an element to be expected in the groundwater of a hydrogeochemical unit under natural conditions
The background value is defined as the 90th percentile of the normal distribution of the parameters.
Challenge:Separation of the background population from geogenic or anthropogenic anomalies within the data sets (component separation))
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201013
Geology of Germany
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201014
Hydrogeochemical units: resulting from aggregation of hydrogeological units of the hydrogeological map of Germany 1:200.000 (HÜK200)
larger hydrogeological units
abt. 1000 hydrogeological units à
186 hydrogeochemical units
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201015
Statistical information of the hydrogeochemical units
Maximum
90%-Quantil
75%-Quantil
Median (entspricht 50%-Quantil)
arithmetisches Mittel25%-Quantil
Minimum
10%-Quantil
80%der Werte
Konz
entra
tion
50%der Werte
Statistical measures: 5-, 10-, 25-, 50-, 75-, 90-, 95-percentiles
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201016
Presentation of results
• WMS-application in the internet: access from any computer connected to the internet (integration e.g. in GIS or Google-Earth)
http://www.bgr.de/Service/grundwasser/huek200/hgc_p90/
• Subdivision of the element concentration ranges in 5 classes:– 90th percentiles of hydrogeochemical units – point data of measuring points
• hightest class: concentrations above GFS-, TVO- or WHO-limit valueswhere they exist
• grey areas: units with insufficient measuring points
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201017
Background Values of Groundwater in Germany
Examples for different parameters:
Sulphate observation points
Bayerisches Landesamt fürUmwelt
IAH Krakow 201018
Examples for different parameters:
Sulphate distribution 90th percentile
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201019
Examples for different parameters:
Vanadium observation points
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201020
Examples for different parameters:
Vanadium distribution 90th percentile
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201021
Example sulfate
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201022
Example: combination of different WMS in ArcGIS
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201023
Benefits
• Direct and straightforward availability of data via the internet
• Basis for evaluation of the chemical status of groundwater bodies
• Evaluation of groundwater analyses based on the regional background values
• Easier identification of groundwater contaminations
• Local specific features of groundwater chemical properties can be identified through the point data
Background Values of Groundwater in Germany
Bayerisches Landesamt fürUmwelt
IAH Krakow 201024
Further plans
• Following requirements of the EG-WFD, many additional measurements have been performed in the meantime
• trace elements with larger gaps in the dataset will be re-evaluated:antimon, cobalt, molybdenum, selen, thallium, uranium, vanadium
• WMS with enlarged dataset shall be available at the end of the year
Background Values of Groundwater in Germany