Coastline Of Koh Samui

[LaoPo]

Ringroad Samui is indeed ca. 53 KM.

I did a measurement on Google Earth and came to around 50 KM but it's difficult to measure exactly since the clouds are in the way.

GROSS Coast Lines Samui, forgetting about the curves and bays I come to a length of 73 Km:

Fascinating stuff for believers & Non-believers...

LaoPo

[JetsetBkk]

Anyway, I did a pretty secure measurement according to the Google Map tools (advised by PoorSucker) and assuming the coordinates of the Google Earth maps are accurate, those measurements are CORRECT !

I don't think anyone is arguing whether the ruler tool is correct or not. We all - I think - accept that it is correct.

The argument is: into how much detail should you go, to do the measurement?

You could draw a rough circle around he island and the result would be on the short side.

Or, you could follow the coast line in as much detail as possible and get a longer figure.

Or, you could measure around every rock, every pebble and every grain of sand and get an enormous figure!

The question is, into how much detail should you go?

I personally think following the high water mark (not around any rocks) is reasonable.

[LaoPo]

Anyway, I did a pretty secure measurement according to the Google Map tools (advised by PoorSucker) and assuming the coordinates of the Google Earth maps are accurate, those measurements are CORRECT !

I don't think anyone is arguing whether the ruler tool is correct or not. We all - I think - accept that it is correct.

The argument is: into how much detail should you go, to do the measurement?

You could draw a rough circle around he island and the result would be on the short side.

Or, you could follow the coast line in as much detail as possible and get a longer figure.

Or, you could measure around every rock, every pebble and every grain of sand and get an enormous figure!

The question is, into how much detail should you go?

I personally think following the high water mark (not around any rocks) is reasonable.

Feel free JetsetBkk, I'm curious to learn your results...

But, let's be realistic. It's about the gross length of the Samui Coastline and I agree with you that a high tide would be acceptable to most of us.

LaoPo

[Rooo]

Easiest solution, get someone who has a boat with a sounder (they measure distance too ),to circumnavigate the coast line.

Just watch the rocks & the reefs

Edited October 29, 2007 by Rooo

[PoorSucker]

Here is another question that I started to think about.

How long is the ring road?

The tourist sites say from 40 to 53 km (maybe you can find other data)

What is the definition of ring road?

The tourist sites say you can reach all beaches from it.

My definition of the ring road is (Nathon, Maenam, Bophut, Chaweng, Lamai, and back to Nathon)

But if all beaches is in the ring road (for ex Chongmoen), is Tesco Lotus on the Ring Road?

Maybe I should start a new tread on this?

[PoorSucker]

Started new thread.

But feel free to contribute.

About the coastline, If you can prove me wrong +-10%, I will by you a beer.

[LaoPo]

Here is another question that I started to think about.

How long is the ring road?

The tourist sites say from 40 to 53 km (maybe you can find other data)

What is the definition of ring road?

The tourist sites say you can reach all beaches from it.

My definition of the ring road is (Nathon, Maenam, Bophut, Chaweng, Lamai, and back to Nathon)

But if all beaches is in the ring road (for ex Chongmoen), is Tesco Lotus on the Ring Road?

Maybe I should start a new tread on this?

Didn't you see post #31 ?

LaoPo

[JetsetBkk]

The argument is: into how much detail should you go, to do the measurement?

You could draw a rough circle around he island and the result would be on the short side.

Or, you could follow the coast line in as much detail as possible and get a longer figure.

Or, you could measure around every rock, every pebble and every grain of sand and get an enormous figure!

The question is, into how much detail should you go?

I personally think following the high water mark (not around any rocks) is reasonable.

Feel free JetsetBkk, I'm curious to learn your results...

But, let's be realistic. It's about the gross length of the Samui Coastline and I agree with you that a high tide would be acceptable to most of us.

LaoPo

A little quiz:

How long are these two paths marked in yellow with red dots, on the north west coast of Samui?:

Here's a clue: they are both less than 500 metres.

Edited October 30, 2007 by JetsetBkk

[LaoPo]

The argument is: into how much detail should you go, to do the measurement?

You could draw a rough circle around he island and the result would be on the short side.

Or, you could follow the coast line in as much detail as possible and get a longer figure.

Or, you could measure around every rock, every pebble and every grain of sand and get an enormous figure!

The question is, into how much detail should you go?

I personally think following the high water mark (not around any rocks) is reasonable.

Feel free JetsetBkk, I'm curious to learn your results...

But, let's be realistic. It's about the gross length of the Samui Coastline and I agree with you that a high tide would be acceptable to most of us.

LaoPo

A little quiz:

How long are these two paths marked in yellow with red dots, on the north west coast of Samui?:

Here's a clue: they are both less than 500 metres.

OK, let me bite...

If the Yellow line in right picture is less than 500 meters, and, say 495 meters, the left one is approximately 18% less and would be around 406 meters...

OK, let's say between 405 and 425 Meters.

Waiting for your answer.....

LaoPo

Edited October 30, 2007 by LaoPo

[JetsetBkk]

OK, let me bite...

If the Yellow line in right picture is less than 500 meters, and, say 495 meters, the left one is approximately 18% less and would be around 406 meters...

OK, let's say between 405 and 425 Meters.

Waiting for your answer.....

LaoPo

Sorry to make you wait my internet has been crap all day!

OK, so you are guessing that the difference is about 18%. But, the actual difference in my two "routes" around the rocky coastline is about 35%

The distances are are: 257 metres for the route that goes around the rocks and 168 metres for the simple curved route that jumps over them.

So if the whole island was rocky at the coast - which it isn't, of course - the actual distance you'd have to walk following all the rocky outcrops could be a lot more (35%) than the simple curved line around the coast.

Now my brain hurts so I don't think I can add any more.

[JetsetBkk]

If you want to read up more about how to measure a coastline...

http://www.vanderbilt.edu/AnS/psychology/c...p/Fractals.html

The length of a coastline

Mandelbrot began his treatise on fractal geometry by considering the question: "How long is the coast of Britain?" The coastline is irregular, so a measure with a straight ruler, as in the next figure, provides an estimate. The estimated length, L, equals the length of the ruler, s, multiplied by the N, the number of such rulers needed to cover the measured object. In the next figure we measure a part of the coastline twice, the ruler on the right is half that used on the left.

Measuring the length of a coastline using rulers of varying lengths.

But the estimate on the right is longer. If the the scale on the left is one, we have six units, but halving the unit gives us 15 rulers (L=7.5), not 12 (L=6). If we halved the scale again, we would get a similar result, a longer estimate of L. In general, as the ruler gets diminishingly small, the length gets infinitely large. The concept of length, begins to make little sense.

[LaoPo]

If you want to read up more about how to measure a coastline...

http://www.vanderbilt.edu/AnS/psychology/c...p/Fractals.html

The length of a coastline

Mandelbrot began his treatise on fractal geometry by considering the question: "How long is the coast of Britain?" The coastline is irregular, so a measure with a straight ruler, as in the next figure, provides an estimate. The estimated length, L, equals the length of the ruler, s, multiplied by the N, the number of such rulers needed to cover the measured object. In the next figure we measure a part of the coastline twice, the ruler on the right is half that used on the left.

Measuring the length of a coastline using rulers of varying lengths.

But the estimate on the right is longer. If the the scale on the left is one, we have six units, but halving the unit gives us 15 rulers (L=7.5), not 12 (L=6). If we halved the scale again, we would get a similar result, a longer estimate of L. In general, as the ruler gets diminishingly small, the length gets infinitely large. The concept of length, begins to make little sense.

I would appreciate if you measure Samui's coastline according to this Acabadabra (for me at least).

Not my piece of cake...

LaoPo

[Chayaphum]

the Richardson effect......

http://en.wikipedia.org/wiki/Lewis_Fry_Richardson

easy question....difficult to answer (calculating)

Chayaphum

to PoorSucker

.... another question for a new tread....what is the size (km²) of samui during flood/ebb?

[JetsetBkk]

I would appreciate if you measure Samui's coastline according to this Acabadabra (for me at least).

Not my piece of cake...

LaoPo

:D I don't think I have enough years left in me!

[LaoPo]

I would appreciate if you measure Samui's coastline according to this Acabadabra (for me at least).

Not my piece of cake...

LaoPo

:D I don't think I have enough years left in me!

So, we have to settle more or less with a coastline of, between 87-90 km ?

LaoPo

[gerrysamui]

Easiest solution, get someone who has a boat with a sounder (they measure distance too ),to circumnavigate the coast line.

Just watch the rocks & the reefs

OK, I´m that someone. Going around with a boat gives about 120 kms measured by GPS (not by sounder as that measures only depth). That´s sailing an average distance of 1-2 miles to the coast, going around five islands and other rocks, landing on Koh Tan and Koh Madsum, doing a bit of waterski and then sailing back to the origin. So 90kms should be an accurate figure of real coastline.

[LaoPo]

Easiest solution, get someone who has a boat with a sounder (they measure distance too ),to circumnavigate the coast line.

Just watch the rocks & the reefs

OK, I´m that someone. Going around with a boat gives about 120 kms measured by GPS (not by sounder as that measures only depth). That´s sailing an average distance of 1-2 miles to the coast, going around five islands and other rocks, landing on Koh Tan and Koh Madsum, doing a bit of waterski and then sailing back to the origin. So 90kms should be an accurate figure of real coastline.

Good enough for me !

LaoPo