1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58wellICS 07.060; 17.060Manual methods for the measurement of a groundwater level in a BRITISH STANDA
2、RDBS ISO 21413:2005BS ISO 21413:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2006 BSI 31 January 2006ISBN 0 580 47365 1The British Standards which implement international publications referred to in this document may be foun
3、d in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are respon
4、sible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 30, an inside back cover and a bac
5、k cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesenquiries on the interpre
6、tation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 21413:2005 and implements it as the UK national standard.The UK participation in its p
7、reparation was entrusted to Technical Committee CPI/113, Hydrometry, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any Reference numberISO 21413:2005(E)INTERNATIONAL STANDARD ISO21413First edition2005-10-15Manual me
8、thods for the measurement of a groundwater level in a well Mthodes manuelles pour le mesurage du niveau de leau souterraine dans un puits BS ISO 21413:2005ii iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Terms and definitions .1 3 Water-level measurement using a graduated steel tape .2 3.1
9、 Purpose.2 3.2 Materials and instruments 2 3.3 Data accuracy and limitations2 3.4 Advantages and disadvantages.3 3.5 Assumptions 3 3.6 Procedures .3 4 Water-level measurement using an electric tape .6 4.1 Purpose.6 4.2 Materials and instruments 6 4.3 Data accuracy and limitations6 4.4 Advantages and
10、 disadvantages.7 4.5 Assumptions 7 4.6 Procedures .7 5 Water-level measurement using an air line.10 5.1 Purpose.10 5.2 Materials and instruments 10 5.3 Data accuracy and limitations10 5.4 Advantages and disadvantages.11 5.5 Assumptions 11 5.6 Procedures .11 6 Water-level measurement in a flowing wel
11、l 13 6.1 Purpose.13 6.2 Materials and instruments 13 6.3 Data accuracy and limitations14 6.4 Advantages and disadvantages.15 6.5 Assumptions 15 6.6 Procedures .15 6.6.1 Low-pressure head measurement (direct measurement) .15 6.6.2 High-pressure head measurement (indirect measurement) .15 7 Establishi
12、ng a permanent measuring point16 7.1 Purpose.16 7.2 Materials and instruments 16 7.3 Data accuracy and limitations17 7.4 Assumptions 17 7.5 Procedure .17 Annex A (informative) Corrections for water levels measured in deep wells by steel tapes subject to temperature changes and tape stretch .26 Annex
13、 B (informative) Corrections for water levels measured in wells with the air-line method.28 Bibliography 30 BS ISO 21413:2005iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Internat
14、ional Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with I
15、SO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical c
16、ommittees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to th
17、e possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 21413 was prepared by Technical Committee ISO/TC 113, Hydrometry, Subcommittee SC 8, Ground water. BS ISO 21413:2005vIntr
18、oduction The measurement of a water level in a well constitutes a data-collection process that provides fundamental information about the status of a groundwater system. Accordingly, measured water levels should be sufficiently accurate and reproducible to meet the needs of most data-collection and
19、monitoring programs. Several manual methods commonly used to collect water-level data in wells employ relatively simple measuring devices such as graduated steel tapes, electric tapes, and air lines. In some cases, water-level measurements are required in flowing wells. The procedures associated wit
20、h each of these methods are intrinsically different and subject to varying limitations and accuracies. Standardization of these methods would ensure that the procedures and associated equipment used by the international community to collect water-level data in a well are consistent, and that the res
21、ults can be compared with minimal concern about the relative accuracies and/or the procedures use in collecting the data. BS ISO 21413:2005blank1Manual methods for the measurement of a groundwater level in a well 1 Scope This International Standard develops procedures and prescribes the minimum accu
22、racy required of water-level measurements made in wells using graduated steel tapes, electric tapes and air lines. Procedures and accuracy requirements for measuring water levels in a flowing well are also included, as are procedures required to establish a permanent measuring point. This Internatio
23、nal Standard discusses the advantages and limitations of each method and requirements for recording the data. This International Standard does not include methods that use automated electrical or mechanical means to measure and record water levels. 2 Terms and definitions For the purposes of this do
24、cument, the following terms and definitions apply: 2.1 air line water-level measuring device consisting of a small diameter open-ended tube fixed in position that is accessible from the top of the casing and extends to below the water level in a well where pressurized air measurements can be used to
25、 determine the depth to water 2.2 casing (well casing) tubular retaining structure, which is installed in a drilled borehole or excavated well, to maintain the borehole opening. Plain (unscreened) casing prevents the entry of water and fine material into the well, while open (screened) casing allows
26、 water ingress but should exclude fines 2.3 electric tape water-level measuring device that uses an electrical signal, sent through a cable with fixed distance marks, to determine the water level relative to a fixed reference point. The electrical signal, which is induced when the sensor makes conta
27、ct with the water surface, activates an indicator (typically a light, buzzer or needle) 2.4 flowing well (or overflowing well) well from which groundwater is discharged at the ground surface without the aid of pumping NOTE A deprecated term for this definition is an artesian well. 2.5 graduated stee
28、l tape water-level measuring device consisting of a flat measuring tape with permanently fixed distance marks that can be wound on a reel 2.6 groundwater water within the saturated zone BS ISO 21413:20052 2.7 land surface datum average altitude of land surface at a referenced well 2.8 measuring poin
29、t permanent reference marked on well casing 2.9 static water level (or static head) height, relative to an arbitrary reference level, of a column of water that can be supported by the static pressure at a given point 2.10 well hole sunk into the ground for abstraction of water or for observation pur
30、poses 3 Water-level measurement using a graduated steel tape 3.1 Purpose The purpose of this method is to measure the depth to the water surface (level) below a measuring point using the graduated steel tape (wetted-tape) method. 3.2 Materials and instruments The following materials and instruments
31、are required. 3.2.1 Steel tape graduated in metres and centimetres. A black tape is preferred to a chromium-plated tape because the wetted chalk mark is easier to read against a black tape. A break-away weight should be attached to the ring on the end of the tape with wire strong enough to hold the
32、weight, but not as strong as the tape, so that if the weight becomes lodged in the well, the tape can still be pulled free. The weight should be made of brass, stainless steel or iron. 3.2.2 Coloured chalk. 3.2.3 Clean cloth. 3.2.4 Pencil and eraser. 3.2.5 Steel tape calibration and maintenance equi
33、pment log book. 3.2.6 Water-level measurement field form (see the example in Figure 6). 3.2.7 Equipment to gain access to the well (wrenches, crow bars, manhole keys, etc.). 3.2.8 Common household chlorine bleach or other suitable disinfectant. 3.3 Data accuracy and limitations The following data ac
34、curacy and limitations apply. a) Independent graduated steel tape measurements of static water levels should agree within 1,0 cm for depths of less than 60 m; BS ISO 21413:20053b) For depths between 60 m and 150 m, independent measurements using the same tape should agree within 2,0 cm. When measuri
35、ng deep water levels (i.e. greater than 300 m), errors due to the effects of thermal expansion and of stretch produced by the suspended weight of the tape and plumbing weight warrant consideration (see Reference 2, p. 3). An example of correcting a deep water level for thermal expansion and stretch
36、of a steel tape is given in Annex A. However, because the equipment required to measure temperatures at land surface and down the well may not always be readily available, the corrections described in Annex A are not required for the purposes of this International Standard, though the practitioner s
37、hall note on the water-level field form (see the example in Figure 6) whether or not any such corrections were applied. c) At least once every twelve months, the steel tape should be calibrated against another steel tape that is dedicated as a calibration tape and is not used in the field. If the st
38、eel tape does not meet test criteria, then it must be removed from service. Records of these tests shall be kept. d) If the well casing is angled, instead of vertical, the depth to water will have to be corrected. If the casing angle is unknown and a correction is not feasible, this should be noted
39、in water-level measurement field form (see the example in Figure 6). 3.4 Advantages and disadvantages The graduated steel tape method is easy to use and is considered to be the most accurate method for measuring the water level in nonflowing wells of moderate depth. However, it may be impossible to
40、get reliable results if water is dripping into the well or condensing on the well casing. Also, the method is not recommended for measuring pumping levels in wells. 3.5 Assumptions The following assumptions apply in the use of the graduated steel tape method. a) An established measuring point (MP) e
41、xists and the distance from the MP to land-surface datum (LSD) is known (see the example in Figure 6). See the technical procedure described in Clause 7 for establishing a permanent MP. b) The MP is clearly marked and described so that all measurements will be taken from the same point. c) The resul
42、ts from previous water-level measurements made at the well are available for estimating the length of the required tape. d) The steel tape will retain the chalk. e) The well is free of obstructions. Well obstructions, if present, could cause errors in the measurement if the obstructions affect the p
43、lumbness of the steel tape. 3.6 Procedures The following procedures for measuring water levels in a well with a graduated steel tape shall be observed. a) Apply the coloured chalk to the lower metre of the tape by pulling the tape across the chalk. The wetted chalk mark will identify that part of th
44、e tape that was submerged. b) Lower the weight and tape into the well until the lower end of the tape is submerged below the water (more than one attempted measurement may be needed to determine the length of tape required to submerge the weight). Once the end of the tape is submerged, continue to l
45、ower the tape into the well until the next whole metre graduation mark is opposite the MP. This whole number shall be recorded in the “MP HOLD” (Figure 1) column of the water-level measurements field form (see the example in Figure 6). BS ISO 21413:20054 c) Pull the tape back to the surface before t
46、he wetted chalk mark dries and becomes difficult to read. Record the number of the wetted chalk mark (sometimes referred to as the cut) in the “WETTED CHALK MARK” (Figure 1) column of the water-level measurements field form (see the example in Figure 6). d) Subtract the wetted chalk mark number from
47、 the number held to the MP, and record this number in the “DEPTH TO WATER FROM MP” (Figure 1) column of the water-level measurements field form (see the example in Figure 6). The difference between these two readings is the depth to water below the MP. e) Apply the MP correction to get the depth to
48、water below or above land-surface datum (LSD). If the MP is above land surface (see the example in Figure 6), the distance between the MP and land surface datum is subtracted from the depth to water from the MP (see the example in Figure 6) to obtain the depth to water below land surface. If the MP
49、is below land surface, precede the MP correction value with a minus () sign and subtract the distance between the MP and land surface datum from the depth to water from the MP to obtain the depth to water below land surface. Record this number in the “DEPTH TO WATER FROM LSD” (Figure 1) column of the water-level measurements field form (see the example in Figure 6). If the water level is above LSD, record the depth to water above land surface as a negative number. f) Make a check measurement by repeating steps a) through e). The check measur
