[Tagging] Coastline for rivers, estuaries and mangroves?

Colin Smale colin.smale at xs4all.nl
Mon Sep 3 22:23:40 UTC 2018


Baseline is not the same as coastline, so the definition you refer to is
not what we are looking for. 

Coastline is a geographic feature, and is normally based on high water. 

Baseline is a political feature, based on the low water mark, and
simplified around bays, inlets and islands. This is the baseline from
which the 12nm territorial limit is measured, and also the 200nm EEZ and
median lines if applicable. Water on the landward side of the baseline
(e.g. lakes, inlets, estuaries) is referred to as internal waters, i.e.
belonging to the land mass itself for the purposes of maritime law.

On 2018-09-03 23:58, Graeme Fitzpatrick wrote:

> This has recently been discussed on the Australian list, with reference being made to http://www.ga.gov.au/scientific-topics/marine/jurisdiction/maritime-boundary-definitions, which is based on the UN Convention on the Law of the Sea http://www.un.org/Depts/los/convention_agreements/convention_overview_convention.htm. 
> For our discussion now: 
> The term Territorial Sea Baseline (TSB) refers to the line from which the seaward limits of Australia's Maritime Zones are measured. These include the breadth of the territorial sea; the seaward limits of the contiguous zone, the exclusive economic zone and, in some cases, the continental shelf. 
> The territorial sea baseline may be of various types depending upon the shape of the coastline in any given locality: 
> * The Normal baseline corresponds with the low water line along the coast, including the coasts of islands. Under the Convention, normal baseline can be drawn around low tide elevations which are defined as naturally formed areas of land surrounded by and above water at low tide but submerged at high tide, provided they are wholly or partly within 12 nautical miles of the coast. For Australian purposes, normal baseline corresponds to the level of Lowest Astronomical Tide (LAT) [1].
> * Straight baselines are a system of straight lines joining specified or discrete points on the low-water line, usually known as straight baseline end points. These may be used in localities where the coastline is deeply indented and cut into, or where there is a fringe of islands along the coast in its immediate vicinity.
> * Bay or river closing lines are straight lines drawn between the respective low-water marks of the natural entrance points of bays or rivers.
> Waters on the landward side of the baseline are internal waters for the purposes of international law." 
> & NB that they say that the Normal baseline is the low water line! 
> The UN's definitions: 
> Straight baselines 
> 1. In localities where the coastline is deeply indented and cut into, or if there is a fringe of islands along the coast in its immediate vicinity, the method of straight baselines joining appropriate points may be employed in drawing the baseline from which the breadth of the territorial sea is measured. 
> 2. Where because of the presence of a delta and other natural conditions the coastline is highly unstable, the appropriate points may be selected along the furthest seaward extent of the low-water line and, notwithstanding subsequent regression of the low-water line, the straight baselines shall remain effective until changed by the coastal State in accordance with this Convention. 
> 3. The drawing of straight baselines must not depart to any appreciable extent from the general direction of the coast, and the sea areas lying within the lines must be sufficiently closely linked to the land domain to be subject to the regime of internal waters. 
> 4. Straight baselines shall not be drawn to and from low-tide elevations, unless lighthouses or similar installations which are permanently above sea level have been built on them or except in instances where the drawing of baselines to and from such elevations has received general international recognition. 
> 5. Where the method of straight baselines is applicable under paragraph 1, account may be taken, in determining particular baselines, of economic interests peculiar to the region concerned, the reality and the importance of which are clearly evidenced by long usage. 
> 6. The system of straight baselines may not be applied by a State in such a manner as to cut off the territorial sea of another State from the high seas or an exclusive economic zone. 
> Article9 
> Mouths of rivers 
> If a river flows directly into the sea, the baseline shall be a straight line across the mouth of the river between points on the low-water line of its banks.
> So, unless any of us want to argue with the UN, or suggest that they change their definitions to suit OSM! :-), I think that they could be counted as the final word? 
> Thanks 
> Graeme 
> _______________________________________________
> Tagging mailing list
> Tagging at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20180904/325844a3/attachment.html>

More information about the Tagging mailing list