[talk-ph] On editing PH coastlines

[Maning Sambale]

Hi,

Since my etrex GPS died,  I have resorted to coastline mapping to
improve previous coastline import.  I have completed several islands
already and my next target is Luzon mainland (already completed most of
north-east Luzon up to Ilocos Sur).  At first, I thought it should be
easy, just load LANDSAT WMS and your good to go.  But really it isn't.

Because, 

1) coastline is a fractal problem [1], at varying zoom-levels you get
different details.  Using landsat, you need to be at zoom 14-16 to get
the most detail.

2) I find it difficult to select, move, and delete nodes of the SRTM
generated coastline.  You have to use several keystrokes and
mouse-clicks.  What I do instead is delete several coastline ways and
then create a new coastline way.

Some questions:

1) How do we map mangrove [2] areas along coastlines?  In the "field"
mangroves are either inland extending to the coast and even beyond
coastline.  Do we include mangroves in inter-tidal areas as part of the
coastline?

2) Where do coastline and large rivers converge?  River deltas [3] is
particularly problematic.

3) Sand bars? Siltation areas?  Any suggestions on how we map this?

Me thinks: coastlines will never be complete because we have so much
coastline and the threat of sea-level rise due to climate change




[1] http://library.thinkquest.org/26242/full/ap/ap4.html
[2] http://en.wikipedia.org/wiki/Mangroves
[3] http://en.wikipedia.org/wiki/River_delta

-- 
cheers,
maning
------------------------------------------------------
"Freedom is still the most radical idea of all" -N.Branden
wiki: http://esambale.wikispaces.com/
blog: http://epsg4253.wordpress.com/
------------------------------------------------------