Welcome to EDMA - Environmental Data Map Application

The application was created in order to function as data bank with what is related with the environmental pollution and generally with the quality of the environment in Greece.

In this phase you can find field data of measurement and analysis in the underground waters of the area of Psachna in Evia. Some data has been added which can be found useful, such as the pollutant sources of Evia, the Natura of Greece, the aquifers of Greece and Kapodistriaka borders of the municipalities.

The application has available tools for the distance measurements and the acreage of the area as well as the availability for the user to load an Kml file and to match it with the existing data.


The application was developed within the limits of the postgraduate thesis of the Postgraduate Program “Environmental Planning of infrastructure projects” of the Hellenic Open University. The editor was Mr. Dimitrios Margaritis, Environmental Engineer of the DUTH and the supervisor professor Ms. Maria Perraki Assistant Professor in Mineralogy, School of Mining and Metallurgical Engineering of NTUA.


Field Measurements

Depiction of the points of samples’ taking for the control of the underground waters, the measurements and the samples’ analysis were granted from the editors of the below mentioned projects.

• Vasiliou E. 2013 “Investigation of the presence of heavy metals and specifically forms of trivalent and hexavalent chromium, in the undergroundwaters of ophiolite mazes and loose formation of Central Evia.Post graduate Thesis. AUA Athens.
• Filippou A. 2015 “Study of the mechanisms of oxidation of chromium in the natural waters of Psachna Evia” NTUA, Athens.
• Chiou E. 2014 “Hydrochemistry of underground waters in the ultrabasic rocks of Central Evia” Post graduate Thesis, NTUA Athens.

pH –Active Acidity
Depiction of the pH measurements at the sample taking points with color distribution for the ease of the user.

The pH of the waters is generally decreasing as the water body comes of age. A new water body is usually alkaline (pH >7) and slowly as the time goes by it becomes acidic (pH < 7).This is due to the compilation of organic materials which rakish CO2 when is is decomposed.The pH of the underground water is an important factor of disintegration. The acidic environment favors the subtraction of Fe and Al the mineral matrix as well as the compilation of SiO2. The pH can also decrease from the oxidation of ammonia, which comes from the use of manure as a fertilizer, s well as the oxidation of flints.(FeS2).

Redox potential
Depiction of the measurements of the Redox potential (or Eh) at the points of the samples’ taking with color distribution of the measurements for the ease of the user.

Knowing the potential of redox (Redox or Eh) of an aquatic environment it is possible to calculate with precision the compilation of ions or compounds in this environment. On the surface of the sea the Eh=+3 (oxidant environment), because of air enrichment and close to the bottom Eh=_0,6(reducing environment because of excess organic material and lack of oxygen. The values of the Redox potentiality are very important as they connect with the oxidant environment of the aquifers and by extension with the oxidation of the trivalent chromium to hexavalent (Oze,2003)

NO3 - Nitrates
Depiction of the measurements of the nitrates NO3 at the points of the samples taking with color distribution of the measurements for the ease of the user.

The nitrates make us the final product of the natura ldecompose of organic nitrogen compounds.It is possible that they come from animal faecal, fertilizers or previous use of water by the man. In the drinking water the desirable limit is 25mg/l, while the maximum permittable limit is 50mg/l.The presence of nitrates above the permitted limits shows the reaction of biological pollutants or the mixture with the irrigation waters from fertilized areas. Increased contents in nitrates, can cause very serious diseases such as carcinogenesis. The nitrates constitute the main oxidant means during the oxidation of the trivalent to hexavalent chromium, from human activities.

Cr Total - Chromium
Depiction of the Cr Total measurements at the points of samples’ taking with color distribution of the measurements for the ease of the user.

The compilation of chromium on the soil is mainly determined from its content of the mineral matrix. Thus, the highest contents are observed in soils which come from basic and ultrabasic rocks and they range from 200-1800mg/kg (Fantoni et al.,2002). In the water chromium is usually detected with its trivalent from as it quite cumbersome and of low toxicity. The permitted limit of the Cr-Total in the water is 50μg/l.

Cr (VI) - Hexavalent Chromium
Depiction of the measurements of the hexavalent chromium Cr(VI) at the points of sample taking with color distribution for the ease of the user.

On contrary with the trivalent, the hexavalent chromium is particularly soluble and agile. The presence of oxidant means such as nitrates or manganese oxides can cause very fast ioxudation of the trivalent to hexavalent. The pH makes us a very important factor for the eduction of Cr(VI) to Cr(III) on the soil from the organic matter. The more acid the soil the faster the reduction is (Hossner et al.,1998)

Pollutant Sources
Depiction of pollutant sources of the surrounding area of Evia.

• Dandalos H & Zoropas B 2009 “Register and valuation of the hydrogeology characters of the underground waters and the aquifer systems of the country”-Subproject 2:Census of pollutant sources IGME, Athens.


The limits of the underground waters of Greece are included. The underground waters constitute the total of waters which are found under the surface of the ground in the satiety zone and in immediate contct with the soil or the subsoil. Source: Ministry of Environment,Energy and Climatic Change


The Natura network 2000 constitutes a European Ecological network of areas, which host natural types of ecotypes and habitats of species which are very important in European level.The available data constitutes the 29 edition (v.29)which arose after the update of the data base Natura 2000 in March 2011. Source: Ministry of Environment, Energy and Climatic Change.

Municipal Borders (Kapodistrias)

The borders of the country municipalities according to the Kapodistria plan. Source. Land registry and cartography of Greece.


Upload Tool

Selecting the specific tool, the user can load one of his own files of (type) Kml ,GPX ot GeoJSON and he can also choose the color he wants his file data to be depicted and by selecting Apply his file is depicted on the application map. The file is not stored on the application but it is used only by the user to contrast his data with those of interest from the application

Export Tool

With the use of this specific selection the user can store a picture from the map with the desired data to be depicted in png form. The picture is stored in the file the user has set for the receipt of files on the browser he uses.

Measure Tool

Using the specific tool the user can select, if he wishes, to count an area in the map or he can set an area and he can calculate the acreage. By pressing the button of the tool, a window appears with the choices Distance, Area and Remove measurements. We select the type of measurement we want to use and by pressing left click with the mouse on the map, we set the area or the desired points to be calculated; by right click we finalize our choices and the application gives us the result.If we want to remove the measurements from the map we choose Remove Measurements.

Table Tool

The choice Table is literally an attribute table. By selecting it, a window opens which depicts the table with the layers data which is loaded on the application. The user selects the layer he wishes to see from layer and a table of the data from the corresponding layer appears. The possibility of choosing the element is given, where it is marked on the map with different color, as well as zooming on the specific point by choosing zoom. There is the choice clear which clears the chosen elements of the user. The user can ask for the filter to have specific data. By the choice move all the choices of elements are moved at the beginning of the table so he can see them easier.Finally by clicking on the titles of the columns a distribution of data is done in increasing or decreasing series. To close the window table we select the button Table again

Search Tool

On the specific space the user can write the area he’s interested on and the application can zoom on that area. The buttons plus and minus are found on the left edge of the map frame and they are used to zoom in and zoom out on the map. The same operation can be made with the scroll wheel of the mouse.

The scalebar is found on the down left edge of the map and it informs us about the map scale we are viewing at the moment.

Viewing button in full screen window. It is found on the right edge of the map; by selecting it we can view the map in full screen in order to observe it easily. By pressing esc we return to the initial window.

The layers button is found on the right side of the map. By selecting it the user can see the layers which are loaded on the application . On the window he opens he can choose which layers he wants to appear on the map as well as he has the possibility to adjust the transparency of each layer with the bar found below the title of each layer.He can zoom in on the layer and he can also download the layer file in KML type..

ΤThe Legend is found under the layers button. By selecting it, it shows us on a window the legend of the map.


Here you can find some screenshots of the application

Main Screen

Table Tool

Upload Tool