WKP - OpenEarth/GoogleEarth

An OpenEarth script has been developed to convert the database tables to file formats that can be loaded in GoogleEarth for presentation purposes. In order to do so, please download the OpenEarth script to your computer (right-click and option "save link as...") and start the program by double-click on the file. When this file is loaded in GoogleEarth, the side bar area will show the “database_DiPol_....” in the temporary user data area (Figure A.1). Note that the “Raw data” section may not always be present or filled.

Figure A.1: DiPol database added to the Google Earth side bar (Dutch language example).


Unfolding the “Integral parameters” will allow you to select a parameter for presentation, see Figure A.2.

Figure A.2: DiPol database with integral parameters unfolded.


The parameter ticked will be shown in the map by coloured dots and a scale bar (Figure A.3) representing its value. The colours scales are selected to reflect the range from “good” (blue) to “bad” (red).

Figure A.3: GoogleEarth based presentation showing one of the stations on the map, and the values of a user-selected integrated parameter (TUmax-Fish) at the relevant sampling dates by colours.


Clicking one of the dots representing an individual sample, will reveal the tabulated values of all integrated parameters plus the sample characteristics (Figure A.4).

Figure A.4: Tabulated properties and values of all integrated parameters belonging to an individual sample.


Clicking an integrated parameter name in the side bar will provide a pop-up window with an explanation of this parameter (Figure A.5).

Figure A.5: Explanation of a selected integrated parameter.


For information on the OpenEarth initiative we refer to www.openearth.nl: open source management of Data, Models and Tools for marine & coastal science & technology.


Integrated parameters to characterise water, suspended matter and sediments

The DiPol database in total contains 421 different combinations of parameters, matrices (water, SPM, sediment) and analysis methods. Because every sample comprises its own subset of these 421 combinations, it is very difficult if not impossible to judge the results and to compare different sites or samples. Having recognised this problem along the way, DiPol experts decided to use integrated parameters to characterise the quality of water, SPM and sediment samples. Their general use is that they greatly reduce the amount of information to be processed by the human mind, thus allowing for easier comparison of samples and sites and thus for easier identification of trends and gradients.

Some methods to derive certain integrated parameters expressing the predicted toxicity based on the analyses of water, SPM or sediment samples, have been derived from the EU funded European Research Project MODELKEY (www.modelkey.org).

Toxic Units (TU)

The logarithm of the maximum value for any substance analysed of the ratio between the actual concentration and the LC50 is determined. Correlation with observed ecological effects has pointed out that a value of log(TUmax) < -3 offers no ecological risk, where a value of log(TUmax) > -1 offers a high ecological risk. This way of calculating toxicity can be differentiated between different species groups (algae, macro-invertebrates and fish).


The multi-substance potentially affected fraction of species (msPAF) calculates the relative share of the species that are expected to be affected by the measured cocktail of chemicals (taking into account mixture toxicity). A value of msPAF < 0.05 is generally considered to represent an acceptable ecological risk where a value of msPAF > 0.5 can be considered to offer a high ecological risk.

WFD related Environmental Quality Standards

The maximum ratio between the observed concentration and the Water Framework Directive related Maximum Allowable Concentration Environmental Quality Standards (MAC-EQS) is calculated. This ratio should be below 1.0.


The maximum ratio between the observed concentration of certain indicator bacteria for the presence of pathogens (like coliform bacteria) and the associated threshold value is calculated. This ratio is presented with two different colour scales: one expressing the suitability for bathing, and one expressing the general surface water quality:


Surface waters

Bathing waters

>10.000 MPN/100ml E.coli

>5.000 MPN/100ml enterococci

<10.000 MPN/100ml E.coli

<5.000 MPN/100ml enterococci

<2.000 MPN/100ml E.coli

<1.000 MPN/100ml enterococci


Integrated Biomarker Response

The measured toxicity (or rather toxic potency) is determined by a series of in vitro bio-assays on sediment extracts, as discussed in the WP 3 report. The results of these bio-assays are expressed as the Integrated Biomarker Response (IBR). This indicator has a value in the range of 0 (lowest toxic potency) to 100 (highest) toxic potency integrated “toxic potency”.

Harbour of Harwich in England

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