Water Level Hat

HAT Dunbarton 4.6m . MHWS Dunbarton -4.2m . MHWS Tide level below HAT 0.4m . Wire height above HAT 18.0m . Wire height above the water 18.4m . Mast height above water -15.0m . Clearance 3.4m. It is a good idea with any tidal height situation to draw out as much of the information as you can to create a picture. Often once the figures you know

HAT Highest Astronomical Tide The highest predicted astronomical tide. The following datums will only be returned for only some stations It is referenced to the primary bench mark at the station and is held constant regardless of changes to the water level gauge or tide staff. NN1954 Norway Normal Null 1954 Norwegian Norwegian

We also think that it can help in planning irrigation system and water management. By setting negative elevation, Bathymetry study is also possible. The elevation layered on the map is in meters and is from sea level. The elevation is zero for the sea level. Negative elevation means depth below sea level. Data Sources Mazpzen, TNM, SRTM, GMTED

Mean sea level MSL is not the only water level determined by long-term tidal measurements. Highest astronomical tide HAT, for instance, is the highest tide ever seen in the measurement record at a given point. It indicates the grass line, or the level above which most structures are built.

For example LAT and HAT are relatively recent concepts, with the first official usage being found in 1960. The tables below show some historic tidal levels and their dates of usage. UK Ordnance Survey Ref 2 . HWMOT High Water Mark of Ordinary Tides 1868 to 1935. LWMOT Low Water Mark of Ordinary Tides 1868 to 1935

The level under these circumstances is known as a 'storm surge' 'negative surge' in the case of level lower than LAT. HAT and LAT are determined by inspecting predicted sea levels over a number of years. Note The values of HAT and LAT may not be the same as in other reference sources. The value given in any source depends on the

Mean Diurnal Tide Level MLW Mean Low Water MLLW Mean Lower-Low Water STND Station Datum GT Great Diurnal Range MN Mean Range of Tide DHQ Mean Diurnal High Water Inequality DLQ HAT Date amp Time HAT Date and Time LAT Lowest Astronomical Tide LAT Date amp Time LAT Date and Time Tidal Datum Analysis Periods Showing datums for

The vertical reference for the astronomic tide is m30. For this chart, the m30 value is 1.76 feet above mean lower low water MLLW, and 1.06 feet above mean sea level MSL. HAT is the elevation of Highest Astronomical Tide for the station shown. No predicted tide referenced to MSL or MLLW should ever be higher than HAT.

HAT. Highest Astronomical Tide. The elevation of the highest predicted astronomical tide expected to occur at a specific tide station over the time period of 40 years. The 40 years period will include 2 National Tidal Datum Epoch periods. A fixed base elevation at a tide station to which all water level measurements are referred. The datum

LAT and HAT are not the extreme water levels which can be reached, as storm surges may cause considerably higher and lower levels to occur. See Tidal Range. The Highest Astronomical Tide HAT has been determined at places where there has been an operational tide gauge at some point in time. Generally HAT is well defined at Standard ports where