SIST EN 14968:2006

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Semantics for groundwater data interchangePomen in definicija izrazov pri izmenjavi podatkov o podtalniciSémantique pour l'échange de données concernant les eaux souterrainesSemantik für den Austausch von GrundwasserdatenTa slovenski standard je istoveten z:EN 14968:2006SIST EN 14968:2006en35.240.9913.060.10ICS:SLOVENSKI
STANDARDSIST EN 14968:200601-november-2006







EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14968August 2006ICS 13.060.10; 35.240.99 English VersionSemantics for groundwater data interchangeSémantique pour l'échange de données concernant leseaux souterrainesSemantik für den Austausch von GrundwasserdatenThis European Standard was approved by CEN on 1 August 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2006 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14968:2006: E



EN 14968:2006 (E) 2 Contents Page Foreword.3 Introduction.4 1 Scope.5 2 Terms and definitions.5 3 File structure for data interchange.7 4 Piezometric concepts.7 5 Interchange prerequisites.14 6 Object dictionary.14 7 Attribute dictionary.20 Annex A (normative) Data model.43 Annex B (informative) Lithology name.45 Bibliography.50



EN 14968:2006 (E) 3 Foreword This document (EN 14968:2006) has been prepared by Technical Committee CEN/TC 318 “Hydrometry”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2007, and conflicting national standards shall be withdrawn at the latest by February 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.



EN 14968:2006 (E) 4 Introduction Piezometric data, e.g groundwater level, pressure, groundwater flow, represent a valuable resource and their value is likely to increase in the context of today at the European, national and local levels. Indeed, the environment is one of the main concerns of the European Union, and it is reflected in the new EU Directives such as the "EU Water Framework Directive" requesting that knowledge regarding environment be shared at the national or international levels. Equally, groundwater quantitative data also represent a source of wealth for local actors (cities, local authorities, private companies, etc.) in undertaking their present activity. For example, a town that uses groundwater for drinking water needs groundwater data to define its drinking water policy, and run its drinking water plant. Towns can directly provide the data that they need or, if data are not available; they have to collect them from various producers that are sometimes located in different countries. In this latter case, this standard provides for a unique data exchange interface which will help towns to collect data more easily and producers to disseminate them quicker. The aim of this standard is to describe data necessary to produce "initial" groundwater quantitative data. The description of aggregate data for groundwater lies outside the scope of this standard. For example, the depth measurement can be carried out in accordance with this standard, but not the altitude measurement. This standard is designed to meet producers' needs and not to define data that are required for exchange between national or European organizations. This standard gives the complete semantic basis necessary to store and exchange groundwater quantitative data. To perform such exchanges, the producer may use a XML file such as recommended by European organizations but these semantics can be used with other file formats (text file, HTML).



EN 14968:2006 (E) 5 1 Scope This standard covers the semantics (meaning) of data exchanged between data producers, users and databanks, independently from the software device and the formats used to exchange the files. It provides a consistent set of terms defining selected objects and their related attributes. The standard is not applicable to:  data describing domestic uses (drinking water, waste water) or qualitative aspects ;  real time data or data calculated from models;  all the various characteristics on the organizations exchanging data concerned;  debimetric measures.
2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 aquifer system hydrogeological entity within which all components are in hydraulic continuity and that is bound by limits representing an obstacle for the dissemination of any perceptible effect outside the system 2.2 archive data data stored to keep knowledge about an object for a given period of time 2.3 attribute characteristic of an object or entity [ISO/IEC 11179-1] 2.4 calculated data data established from calculations carried out to reach different goals: forecast, simulation, design, etc. 2.5 concept unit of thought constituted through abstraction on the basis of characteristics common to a set of objects
2.6 data representation of facts, concepts, or instructions in a formalized manner, suitable for communication, interpretation, or processing by humans or by automatic means
2.7 data element unit of data for which the definition, identification, representation, and
permissible values are specified by means of a set of attributes [ISO/IEC 11179-1]



EN 14968:2006 (E) 6 2.8 data element dictionary information resource that lists and defines all relevant data elements
2.9 data interchange process of sending and receiving data in such a manner that the information content or meaning assigned to the data is not altered during the transmission 2.10 data length maximum size given in a number of characters
2.11 data producer private or public entity in charge of data production and responsible for the validity of these data when they are published
2.12 data model description of the organization of data in a manner that reflects an information structure
NOTE See Annex A. 2.13 data type format used for the collection of letters, digits, and/or symbols, to depict values of a data element, determined by the operations that may be performed on the data element
2.14 definition statement that expresses the essential nature of a data element and permits its differentiation from all other data elements 2.15 entity any concrete or abstract thing of interest, including associations among things 2.16 information (in information processing): knowledge concerning objects, such as facts, events, things, processes, or ideas, including concepts, that within a certain context has a particular meaning 2.17 metadata data that defines and describes other data [ISO/IEC 11179-1] 2.18 object any part of the conceivable or perceivable world
2.19 real time data data generally taken from devices for the immediate knowledge of a phenomenon state



EN 14968:2006 (E) 7 3 File structure for data interchange The data included in the directories presented in Clauses 6 and 7 can be used with any method for data interchange. Any file format can be used to exchange data according to this standard provided that it has no impact on the data structure and the semantics described in the following clauses. 4 Piezometric concepts 4.1 Piezometric time series 4.1.1 General Piezometric time series are a record of the groundwater level over time. They associate a date to the groundwater level at a given moment. Depending on the variability of the groundwater level, measurements will be more or less frequent over a period of time. The groundwater level measurements shall be positive or negative according to the measurement point (see Figure 1). Measurements are negative when the groundwater level rises above the measurement point (as with an artesian well), and positive in all the other cases.
4123 Key 1 height (-) 2 level zero 3 depth to groundwater level (+) 4 measurement point Figure 1 — Qualification of the groundwater level measurements 4.1.2 Type of time series 4.1.2.1 General The groundwater level is measured with discontinuous or continuous time series.



EN 14968:2006 (E) 8 4.1.2.2 Discontinuous time series Discontinuous time series are sets of level measures observed with or without any specific frequency (see Figure 2). 12 Key 1 time 2 depth to groundwater level Figure 2 — Discontinuous time series With this kind of time series, the evolution of the groundwater level between two measures is unknown. Figure 3 shows that measures (example A) conceal two radically different evolutions (examples B and C) of the groundwater level. 12 12
21 Example A Example B Example C Key 1 time 2 depth to groundwater level Figure 3 — Elevation of the groundwater level between measurements



EN 14968:2006 (E) 9 Piezometric measurements shall be made with a sensor. If the sensor does not operate for a shorttime, e.g. sensor breakdown, or if the result has no meaning, at least one piezometric measurement will be missing. In such a case, the missing data shall be identified because there is no continuous series for the measure preceding this missing data and the measure coming after. 4.1.2.3 Continuous time series The groundwater level is known at any moment during the period covered by the continuous time series. Indeed, continuous time series are curves resulting from a permanent measurement of the groundwater level. Time series shall be obtained by using graphical or electronic devices. 4.1.3 Time series presentation Each time series is represented by a set of points in succession over time. Each point represents the groundwater level at a given moment. Points represent the measures of discontinuous time series or the curve inflection point of the continuous time series. To indicate the continuity between two points as shown in Figure 4, each point may be linked to the preceding point. If a point is not linked, it is the first point of a new sequence in the time series. The presence of an initial point therefore indicates that data were not available for the preceding period. 32451 Key 1 initial points 2 depth 3 time 4 current points 5 discontinuity
Figure 4 — Continuous time series presentation 4.1.4 Validation of the measurements The validity of each measurement is described according to the type of measurement method used. Four scenarios are possible: a) Impossible to validate;



EN 14968:2006 (E) 10 b) Valid; c)
Suspect ;
d) Not valid ; By default, all values are specified as ‘Not validated yet’. The operator shall then assign one of the above- mentioned qualifications after examination. A measurement is validated when the producer believes that the data and all the different procedures used to produce them comply with the monitoring protocol. A measurement is not valid when the producer believes that the data or the procedures used to produce them do not comply with the measurement protocol. A measurement is "Impossible to validate" when the operator does not have the information available to determine the validity of the data production according to the measurement protocol ( e.g. historical data from archives). 4.2 Piezometer station 4.2.1 General A piezometer is one method of measuring the piezometric height at a point within an aquifer system. It indicates the pressure at this point, enabling the observer to record the phreatic level or pressure. In the data interchange, only the depths to groundwater level of a piezometer are exchanged.
According to the scope of this standard, the concept of "piezometer" is extended to all artificial structures (well, borehole, gravel-pit) or natural structures (swallow, hole, grottos) which enables the groundwater level to be measured. Each piezometer shall have a unique code given by the country where it is located. 4.2.2 Key features of a piezometer 4.2.2.1 General Each piezometer has two key features: the level measurement point and the altitude benchmark measurement point as shown in Figure 5.



EN 14968:2006 (E) 11 162345
Key 1 plinth 2 level measurement point 3 altitude of surface in relation to the national altitude reference system 4 depth to groundwater level 5 groundwater level 6 altitude benchmark point
Figure 5 —
Key features of a piezometer 4.2.2.2 Level measurement point The level measurement point is the location on the piezometer used as a marker to measure the depth of the groundwater level (for example: the side of the tube of the borehole, the edge of the well, the reference ground level on a gravel-pit, etc.). The level measurement point is 0, which is the basis for all depth measures. It applies to all measurement points. The real height is defined by using benchmark points. 4.2.2.3 Altitude benchmarks Altitude benchmark points are used to compare data from all the piezometers in an aquifer system in order to determine the groundwater level of the system.
Three main locations are generally used to establish an altitude benchmark point: the level measurement point itself (when it is a permanent fixture), the altitude of the surface level or the plinth altitude.



EN 14968:2006 (E) 12 The altitude of the benchmark altitude point can be determined by several means such as maps, GPS, topographic surveying, etc. and it is valid only for a given period of time. The altitude shall be based on the national altitude reference system. The definition of the altitude benchmark point shall ensure the continuity within the time series when the piezometer has been damaged (a chipped tube has been broken), or modified (a new collar has been built). 4.2.3 Monitored aquifer systems A piezometer should be used to monitor the depth of groundwater level of only one aquifer system as shown in Figure 6, even if it has to go through numerous aquifer horizons. 1432 Key 1 aquifer horizons 2 impermeable layers (aquiclude) 3 aquifer system 4 strainers Figure 6 — Aquifer horizons Nevertheless, boreholes going through several aquifer systems may sometimes be also used as piezometers, especially in areas where the number of piezometers is limited (see Figure 7). This situation should be avoided as far as possible, but if such boreholes are used, data related to them shall be identified as coming from multi-aquifer boreholes, so that they can be carefully interpreted.



EN 14968:2006 (E) 13
12354 Key 1 casing 2 unconfined aquifer 3 confined aquifer 4 impermeable layer 5 screens
Figure 7 — A borehole linked to two aquifers The lithology at the piezometer location should also be described, so that information on local variations in the general lithology defined for the whole aquifer can also be provided. 4.2.4 Piezometer history Many events can happen during the lifetime of the piezometer. This kind of information shall be stored with the date since it can be very useful to understand the time series described. These events might be:  a new topographic survey;  the building of a new collar/plinth;  a new measuring equipment;  the destruction of the piezometer head by works; etc. 4.3 Groundwater level producer At a given date, a piezometer is always the responsibility of a producer. The producer might change during the life cycle of the piezometer because the responsibility can move from one producer to another. It is therefore important to keep track of such changes.



EN 14968:2006 (E) 14 4.4 Measurement methods A description of the method used to obtain measurements and the measurement frequency may accompany measurement data. Different methods of measurement may be used such as:  a manual method (manual dipper, scale reading);  a curve plotter (strip chart recording, float recorder, analogical plotter);  a digital recorder (time step fixed or variable). Measurement frequencies shall also be mentioned. These frequencies indicate, for example, that an important variation of the groundwater level is likely to be observed between two measures. The lower the frequency is, the bigger is the probability for this variation. 4.5 Monitoring network of the piezometer Usually, a piezometer is operated within one monitoring network during a given period of time. In some cases, a piezometer can belong to several networks during the same period of time. 5 Interchange prerequisites This standard is intended to facilitate interchange of groundwater data. For efficiency reasons, the following should be carried out before any interchange of groundwater data.  Define the prerequisites for the interchange, in particular, the list of data to be exchanged;  Identify data already defined in this standard;  Specify with partners exchanging data, those data which are not defined in this standard;  Determine the codification systems required to identify the organizations and the aquifer systems involved in the data interchanges, piezometers;  Select a file format to decide the way to organise data in the files to be exchanged;
 Describe the organization involved in the interchanges: who is sending what to whom, when, and
by what means ?  Prepare a formal document such as a contract agreed by the partners involved in the interchanges and containing all these aspects and any additional relevant elements that may prove necessary. 6 Object dictionary 6.1 General This directory contains a list of basic objects used in the field of groundwater.



EN 14968:2006 (E) 15 Each identified object is given: a) a name which appears as the title of the article; b) a description of the concept to explain the agreed meaning; c) the organization(s) responsible for the specific information related to the object and likely be transmitted; d) a list of attributes pertaining to each object. 6.2 Aquifer system An aquifer system is an hydrogeological entity within which all components are in hydraulic continuity and that is bound by limits representing an obstacle for the dissemination of any perceptible effect outside the system (see 2.1).
Data to be exchanged about the list of hydrogeological entities shall be defined by the partners involved in the interchange. This object includes the following information:  Aquifer system code (object identifier);
 Aquifer system name;
 Aquifer system state;  Aquifer system nature;  General information on the aquifer system;  Comments on the aquifer system. 6.3 Measurement method used with the piezometer The measurement method used with a piezometer represents the history of the various methods which have been used with the frequency of the measurements carried out with the piezometer.
Information on the piezometer is the responsibility of the organization(s) providing the data and that uses the piezometer. This object includes the following information:  Starting date of use of the measurement method (object identifier);  Closing date of use of the measurement method;  Measurement method;
 Measurement frequency;
 Comments on the measurement method used on the piezometer.



EN 14968:2006 (E) 16 6.4 Monitoring network A monitoring network is a set of piezometers used for a specific purpose. A piezometer can be operated within several measurement networks, which may vary over a period of time. In this case, all the periods of association of a piezometer to a given network may be specified. The description of the networks to which the piezometer is associated is the responsibility of the organization(s) providing the data and that uses the piezometer. This object includes the following information:  Code of the monitoring network (object identifier);  Name of the monitoring network;  Purpose of the monitoring network.
6.5 Organization Organizations are private or public entities identified for the functions that they play (data producer, operator, etc.) in data exchanges. The list of organizations shall be defined by the partners involved in the data interchange. This object includes the following information:  Organization code (object identifier);
 Organization name;  Organization address 1;  Organization address 2;  Organization address 3;  Organization address 4;  Organization address 5;  Organization address 6;  Comments on the organization. 6.6 Operating period of a piezometer by an organization A piezometer is usually operated by a single organization, known as the manager of the piezometer. However, a piezometer may be managed by two or more organizations. In this latter case, only one organization is responsible for validating data produced.
The piezometer manager(s) can change in the course of time. The period during which an organization has been responsible for the piezometer shall also be specified.
The establishment of the management periods of the piezometer is placed under the responsibility of the organization(s) providing the data and that uses the piezometer.



EN 14968:2006 (E) 17 This object includes the following information:
 Starting date of the operating period of the piezometer (object identifier);
 Closing date of the operating period of the piezometer;
 Operator's internal code of the piezometer. 6.7 Period of association of a piezometer to a network Typically, a piezometer is operated within one monitoring network during a given period of time. In some cases, a piezometer may belong to several networks during the same period of time. This information is the responsibility of the organization(s) providing the data and that uses the piezometer. This object includes the following information:  Starting date of the association period of a piezometer to a monitoring network (object identifier);  Closing date of the association period of a piezometer to a monitoring network;  Operator's internal code of the piezometer. 6.8 Piezometer
Basically, a piezometer is a device to measure the piezometric height at a given point within an aquifer system. It indicates the pressure at this point, enabling the phreatic level or pressure to be observed and recorded. [Source: G. Castany, J. Margat (1977) French dictionary of hydrogeology, Editions du BRGM, Orléans, France]. However, for practical reasons, and in keeping with common practice, in this standard the piezometer concept is extended to all artificial structures (well, borehole, gravel-pit etc.) or natural structures (spring, swallow hole, grottoes etc.) which permit access to the groundwater to measure it. Theoretically, a piezometer is a device used to measure only one groundwater level. As a matter of fact, a piezometer can be used to measure several groundwater levels if it is linked to several layers separately.
Information on the piezometer is the responsibility of the organization(s) providing the data and that uses the piezometer. This object includes the following information:  Piezometer code (object identifier);  Piezometer name;
 Name of the piezometer location;  Type of piezometer;  Creation date of piezometer;  Closing date of piezometer;  Coordinate X of piezometer;  Coordinate Y of piezometer;



EN 14968:2006 (E) 18  Precision on the piezometer coordinates;  Coordinate reference system of the piezometer;  Piezometer
altitude;  Expression of the piezometer time series;
 Confinement condition;  Name of the town;  Piezometer lithology name;  Piezometer lithology type name;  Comments on the piezometer. 6.9 Piezometer altitude benchmark point The altitude benchmark point of the piezometer is a physical point located on the piezometer. Its altitude is measured (more or less precisely) to establish the elevation (z level) of the groundwater piezometric height. For a conventionally built piezometer (a tube rising above the ground level protected by a base or a plinth), three positions can be used as a piezometer altitude benchmark point:  The measurement reference mark (tube rim);  The upper rim of the base or plinth;
 The ground at the foot of the piezometer.
The altitude of these points can be obtained using two methods: either from the measurement carried out by a land surveyor or, directly from a map scaled at 1:25 000 or over (if it is the only source of information available).
The altitude of the altitude benchmark point may be expressed using different reference systems. Several altitude benchmark points of different types (mark, rim or ground) may be used for the piezometer at any given time. Information on the piezometer is placed under the responsibility of the organization(s) collecting data and processing them. This object includes the following information:  Type of the altitude benchmark point of the piezometer (object identifier);  Starting date of the validity of the altitude benchmark point (object identifier);  Closing date of the validity of the altitude benchmark point;
 Altitude of the altitude benchmark point of the piezometer;  Altitude reference system;  Method for the altitude measurement;



EN 14968:2006 (E) 19  Comments on the altitude benchmark point of the piezometer.
6.10 Piezometer event Events may occur on a piezometer. They include facts that the data producer using the piezometer may wish to record as they are considered as being significant to understand the lifecycle of a piezometer and interpret the data that are measured by the piezometer. EXAMPLES:  Rebuilding plinths;  Redefining the altitude benchmark point;  Installing a measurement device.
Information on the piezometer is the responsibility of the organization(s) producing data and processing them. This object includes the following information:  Date of the piezometer event (object identifier);  Description of the piezometer event.
6.11 Level measurement point The level measurement point is the physical point located on the piezometer housing, from which the groundwater level is measured. The difference of level between the level measurement point and the altitude benchmark point shall be known so that the surface altitude of the aquifer system may be determined. With a conventionally built piezometer (with a tube rising above ground level, and protected by a base or a plinth), the height is negative when the altitude benchmark point corresponds to the ground at the foot of the piezometer or the upper rim of the base or plinth. It is equal to zero if the altitude benchmark point corresponds to the measurement point. The description of the marker indicates to which altitude benchmark point the mark refers. The information on the piezometer is the responsibility of the organization(s) acquiring data acquisition or managing them. This object includes the following information:  Starting date of the validity of the level measurement point (object identifier);  Closing date of the validity of the level measurement point;
 Distance between the level measurement point and the altitude benchmark point;  Altitude benchmark point taken as reference;  Comments on the level measurement point;
6.12 Piezometric time series The piezometric time series is measured as a function of time and water levels observed at a given piezometer in an aquifer system.
Variations of heights are discretized to obt
...