ISO 14686:2003 水力測定—井戸の揚水試験—設計、性能、使用に関する考慮事項とガイドライン | ページ 5

2.1

abstraction

removal of water from a borehole or well

2.2

access tube

pipe inserted into a well to permit installation of instruments, and safeguarding them from touching or becoming entangled with the pump or other equipment in the well

2.3

aquifer

lithological unit, group of lithological units, or part of a lithological unit containing sufficient saturated permeable material to yield significant quantities of water to wells, boreholes or springs

2.4

aquifer loss

head loss at a pumped or overflowing well associated with groundwater flow through the aquifer to the well face

2.5

aquifer properties

properties of an aquifer that determine its hydraulic behaviour and its response to abstraction

2.6

borehole

a hole, usually vertical, bored to determine ground conditions, for extraction of water or measurement of groundwater level

2.7

casing

tubular retaining structure, which is installed in a drilled borehole or excavated well, to maintain the borehole opening

Note 1 to entry: Plain casing prevents the entry of water.

2.8

column pipe

that part of the rising main within the well

2.9

cone of depression

that portion of the potentiometric surface that is perceptibly lowered as a result of abstraction of groundwater from a well

2.10

confining bed

bed or body of impermeable material stratigraphically adjacent to an aquifer and restricting or reducing natural flow of groundwater to or from the aquifer

2.11

discharge

volumetric flow rate

2.12

drawdown

reduction in static head within the aquifer resulting from abstraction

2.13

filter pack

granular material introduced into a borehole between the aquifer and a screen or perforated lining to prevent or control the movement of particles from the aquifer into the well

2.14

flow, steady

flow in which parameters such as velocity, pressure, density and temperature do not vary sufficiently with time to affect the required accuracy of measurement

2.15

flow, uniform

flow in which the magnitude and direction of flow at a given moment are constant with respect to distance

2.16

foot valve

non-return valve fitted at the bottom of a suction pipe of a pump

2.17

groundwater

water within the saturated zone

2.18

hydraulic conductivity

volume of water at the existing kinematic viscosity that will move in unit time under a unit hydraulic gradient through a unit area measured perpendicular to the direction of flow

Note 1 to entry: This definition assumes an isotropic medium in which the pores are completely filled with water.

2.19

hydraulic gradient

change in static head per unit of distance in a given direction

2.20

hydrogeology

study of subsurface water in its geological context

2.21

impermeable material

material that does not permit water to move through it at perceptible rates under the hydraulic gradients normally present

2.22

incompetent stratum

stratum unable to stand without support

2.23

isotropic

having the same properties in all directions

2.24

lining

tube or wall used to support the sides of a well, and sometimes to prevent the entry of water

2.25

lining tube

preformed tube used as the lining for a well

Note 1 to entry: See also casing (2.7) and screen (2.39)

2.26

lithology

physical character and mineralogical composition that give rise to the appearance and properties of a rock

2.27

observation well

well used for observing groundwater head or quality

2.28

overflowing well

well from which groundwater is discharged at the ground surface without the aid of pumping

Note 1 to entry: A deprecated term for this type of well is an artesian well.

2.29

permeability

characteristic of a material that determines the rate at which fluids pass through it under the influence of differential pressure

2.30

permeable material

material that permits water to move through it at perceptible rates under the hydraulic gradients normally present

2.31

phreatic surface

upper boundary of an unconfined groundwater body, at which the water pressure is equal to atmospheric

2.32

potentiometric surface

surface that represents the static head of groundwater

2.33

radius of influence

radius of the cone of depression

2.34

rest water level

water level in the pumped well observed under equilibrium conditions when the pump is off

2.35

rising main

pipe carrying water from within a well to a point of discharge

2.36

rock

natural mass of one or more minerals that may be consolidated or loose (excluding top soil)

2.37

running plot

graph of a variable against elapsed time continually updated as measurements are taken

2.38

saturated zone

that part of the earthen material, normally beneath the water table, in which all voids are filled with water

2.39

screen

type of lining tube, with apertures designed to permit the flow of water into a well while preventing the entry of aquifer or filter pack material

2.40

slurry

mixture of fluid and rock fragments formed when drilling or developing a borehole

2.41

specific capacity

rate of discharge of water from a well divided by the drawdown within the well

2.42

specific yield

ratio of the volume of water which can be drained by gravity from an initially saturated porous medium to the total volume of the porous medium

2.43

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

2.44

storage coefficient

volume of water an aquifer releases from storage or takes into storage per unit surface area of the aquifer per unit change of head

2.45

transmissivity

rate at which water of the prevailing kinematic viscosity is transmitted through a unit width of the saturated aquifer under a unit hydraulic gradient

2.46

unconsolidated rock

rock that lacks natural cementation

2.47

unsaturated zone

that part of the earthen material between the land surface and the water table

2.48

water table

surface of the saturated zone at which the water pressure is atmospheric

2.49

well

hole sunk into the ground for abstraction of water or for observation purposes

2.50

well bore storage

volume of water released from within the well itself during a decline in head

2.51

well development

physical and chemical treatment of a well to achieve minimum resistance to movement of water between well and aquifer

2.52

well efficiency

measure of the performance of a production well

2.53

well loss

head loss resulting from flow of groundwater across the well face, including any part of the aquifer affected by drilling, and any filter pack or lining tube, into the well and up or down the well to the pump