| Name |
Type |
English |
Description |
| equinoctialSpringLowWater |
|
|
The level of low water springs near the time of an equinox.
-- Description --
SOURCE [DFDD]. |
| higherHighWater |
|
|
The highest of the high waters (or single high water) of any specified tidal day due to the declination A1 effects of the moon and sun.
-- Description --
SOURCE [DFDD]. |
| higherHighWaterLargeTide |
|
|
The average of the highest high waters, one from each of 19 years of observations.
-- Description --
SOURCE [DFDD]. |
| highestAstronomicalTide |
|
|
The highest tidal level, which can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.
-- Description --
SOURCE [DFDD]. |
| highestHighWater |
|
|
The highest water level observed at a location.
-- Description --
SOURCE [DFDD]. |
| highWater |
|
|
The highest level reached at a location by the water surface in one tidal cycle.
-- Description --
SOURCE [DFDD].
NOTE When used on inland waters it is generally defined as a level that the daily mean water level exceeds less than 5 percent of the time. |
| highWaterSprings |
|
|
An arbitrary level, approximating that of mean high water springs.
-- Description --
SOURCE [DFDD]. |
| indianSpringHighWater |
|
|
A tidal surface datum approximating the level of the mean of the higher high water at spring tides.
-- Description --
SOURCE [DFDD].
NOTE This tidal datum approximates the highest water level observed at a location and is usually above that of the higher high water at spring tides. |
| indianSpringLowWater |
|
|
A tidal surface datum approximating the level of the mean of the lower low water at spring tides.
-- Description --
SOURCE [DFDD].
NOTE This tidal datum approximates the lowest water level observed at a location and is usually below that of the lower low water at spring tides. |
| localDatum |
|
|
An arbitrary datum defined by an authority of a local harbour, from which levels and tidal heights are measured by that authority.
-- Description --
SOURCE [DFDD]. |
| lowerLowWater |
|
|
The lowest of the low waters (or single low water) of any specified tidal day due to the declination A1 effects of the moon and sun.
-- Description --
SOURCE [DFDD]. |
| lowerLowWaterLargeTide |
|
|
The average of the lowest low waters, one from each of 19 years of observations.
-- Description --
SOURCE [DFDD]. |
| lowestAstronomicalTide |
|
|
The lowest tide level that can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.
-- Description --
SOURCE [DFDD]. |
| lowestLowWater |
|
|
An arbitrary level conforming to the lowest tide observed at a location, or somewhat lower.
-- Description --
SOURCE [DFDD]. |
| lowestLowWaterSprings |
|
|
An arbitrary level conforming to the lowest water level observed at a location at spring tides during a period shorter than 19 years.
-- Description --
SOURCE [DFDD]. |
| lowWater |
|
|
An approximation of mean low water adopted as the reference level for a limited region, irrespective of better determinations later.
-- Description --
SOURCE [DFDD].
NOTE Used mostly in harbour and river engineering. Used in inland waters. It is generally defined as a level which the daily mean water level would fall below less than 5 percent of the time and by no more than 0.2 metres during the navigation season. A single level surface is usually chosen as the low water datum for a whole lake. On a river, low water datum is a sloping surface, which approximates the surface of the river at a low state. |
| lowWaterDatum |
|
|
An approximation of mean low water that has been adopted as a standard reference for a limited area.
-- Description --
SOURCE [Based on DFDD].
NOTE 1 It is retained for an indefinite period regardless of the fact that it may differ slightly from a better determination of mean low water from a subsequent series of observations.
NOTE 2 Used primarily for river and harbor engineering purposes. |
| lowWaterSprings |
|
|
A level approximating that of mean low water springs.
-- Description --
SOURCE [DFDD]. |
| meanHigherHighWater |
|
|
The average height of higher high waters at a location over a 19-year period.
-- Description --
SOURCE [DFDD]. |
| meanHigherHighWaterSprings |
|
|
The average height of higher high water at spring tides at a location.
-- Description --
SOURCE [DFDD]. |
| meanHigherLowWater |
|
|
The average of the higher low water height of each tidal day observed over a National Tidal Datum Epoch.
-- Description --
SOURCE [DFDD].
NOTE For stations with shorter series, comparison of simultaneous observations with a control tide station is made in order to derive the equivalent datum of the National Tidal Datum Epoch. |
| meanHighWater |
|
|
The average height of all high waters at a location over a 19-year period.
-- Description --
SOURCE [DFDD]. |
| meanHighWaterNeaps |
|
|
The average height of the high waters of the neap tide.
-- Description --
SOURCE [DFDD]. |
| meanHighWaterSprings |
|
|
The average height of the high waters of spring tides.
-- Description --
SOURCE [DFDD]. |
| meanLowerHighWater |
|
|
The average of the lower high water height of each tidal day observed over a National Tidal Datum Epoch.
-- Description --
SOURCE [DFDD].
NOTE For stations with shorter series, comparison of simultaneous observations with a control tide station is made in order to derive the equivalent datum of the National Tidal Datum Epoch. |
| meanLowerLowWater |
|
|
The average height of the lower low waters at a location over a 19-year period.
-- Description --
SOURCE [DFDD]. |
| meanLowerLowWaterSprings |
|
|
The average height of lower low water at spring tides at a location.
-- Description --
SOURCE [DFDD]. |
| meanLowWater |
|
|
The average height of all low waters at a location over a 19-year period.
-- Description --
SOURCE [DFDD]. |
| meanLowWaterNeaps |
|
|
The average height of the low waters of the neap tide.
-- Description --
SOURCE [DFDD]. |
| meanLowWaterSprings |
|
|
The average height of the low waters of spring tides.
-- Description --
SOURCE [DFDD]. |
| meanSeaLevel |
|
|
The average height of the sea at a tide station measured from a fixed predetermined reference level.
-- Description --
SOURCE [DFDD].
NOTE Usually determined from hourly height readings, for all stages of the tide, over a 19-year period. |
| meanTideLevel |
|
|
The arithmetic mean of mean high water and mean low water.
-- Description --
SOURCE [DFDD]. |
| meanWaterLevel |
|
|
The average of all hourly water levels over the available period of record.
-- Description --
SOURCE [DFDD]. |
| nearlyHighestHighWater |
|
|
An arbitrary level approximating the highest water level observed at a location, usually equivalent to the high water springs.
-- Description --
SOURCE [DFDD]. |
| nearlyLowestLowWater |
|
|
A level approximating the lowest water level observed at a location, usually equivalent to Indian spring low water.
-- Description --
SOURCE [DFDD]. |
| tropicHigherHighWater |
|
|
The highest of the high waters (or single high water) of the tides occurring semimonthly when the effect of the Moon's maximum declination is greatest.
-- Description --
SOURCE [DFDD].
NOTE At these times there is a tendency for an increase in the diurnal range. |
| tropicLowerLowWater |
|
|
The lowest of the low waters (or single low water) of the tides occurring semimonthly when the effect of the Moon's maximum declination is greatest.
-- Description --
SOURCE [DFDD].
NOTE At these times there is a tendency for an increase in the diurnal range. |
