Measuring height above sea level / ground with accuracy

[moogradod]

17 minutes ago, blackcab said:

If you use Google Earth, understand that elevation data refers to the Local Mean Sea Level. That's a really crucial thing to understand if you are researching flood risk.

 

For example, if you check google earth for the height of the sea that is next to Pattaya beach, the beach itself has an elevation of 2-6 meters, even though it is at what most people would perceive to be sea level.

 

<<picture>>

Thank you. Indeed this is a crucial comment. I guess my measurement idea dissolves more and more.

[Sparktrader]

My watch had me 30m under water standing on the sand at beach

[Elkski]

I had an old Casio watch with a barometric altitude feature.   It seems very accurate in terms of my walking.  I used it to follow terrain at 1 level where conditions seemed right for elk to bed and also mushroom foraging.   Seemed to indicate just a couple steps down the hill.   Also fairly accurate on real elevation when I checked to local weather station and set the barometric pressure.    But like everyone else has suggested flooding has a lot more to it than elevation.  

I took surveying in college and they sell handheld levels.  A sighting device that has a level bubble and crosshairs so you could look across terrain to known elevations or previous flood lines.   Soil type is also a factor.   And also what if landowner below you decides to truck in 3 meters of fill.  Which seems to be his right in Thailand. Or builds a wall.  

Siteline2.5x is one example.  Or get an auto leveling one and sturdy tripod.   

[degrub]

Without even a measurement, look to the old practices for houses - second story with strong frame for anything of value, ground floor stuff is disposable or cleanable. 
 

now what to do about the car …..

 

i grew up in rice country. All houses were elevated with a least a crawl

 space if not a second story. Floods were only an inconvenience.  Pity the poor souls that build on grade since it is a little cheaper.  But we all pay in terms of the cost of insurance and devastation from their risk taking. 
 

Cyclones on the other hand…

[simon43]

On 9/8/2022 at 1:53 PM, moogradod said:

I have had a look at that. Never seen any apps that gather so much information from your phone - and I am severely allergic to share personal data. I would not use them even if they were accurate (which they are not I suppose anyway - a dedicated GPS such as the better Garmin models might well be above THB 20K). And this is the price I have seen on websites abroad - might be a multiple in Thailand.

If you're concerned about personal data, then buy a new SIM card for 50 baht, or even a cheapie, throwaway phone for 1,000 baht ????

[digbeth]

it doesn't matter if your house is above sea level but is in a basin that normally requires water to be pumped out, on a heavy downpour, failed pumps and incompetence could lead to the area being flooded with nowhere for water to go, the Surburb of Ransit in north of Bangkok is experiencing this right now, there's a levy around the village but once the canal in the levy overflows, the water is trapped in

[Chris.B]

You need a bottle of 'Sea Level' water It has a marker floating inside which you can take the level from.  ????

 

[moogradod]

28 minutes ago, digbeth said:

it doesn't matter if your house is above sea level but is in a basin that normally requires water to be pumped out, on a heavy downpour, failed pumps and incompetence could lead to the area being flooded with nowhere for water to go, the Surburb of Ransit in north of Bangkok is experiencing this right now, there's a levy around the village but once the canal in the levy overflows, the water is trapped in

Thank you but I always said that the height is only to be used in connection with a topographic map. To detect where possible "basins" are. Please dont think that I would have left out the most obvious. Now I am learning about measuring height above sea level which I think is an interesting subject for there is no absolute sea level. We have witnessed the 2011 flood and it has had a huge impact on our travel plans by car. What I cannot understand that the poperty market in Bangkok is still flourishing as it is. Granted, Bangkok has been flooded because of rain many times long before 2011. I visited BKK the first time in 1975. But it was always a short event just affecting Tuk-Tuk prices for a while.

[digbeth]

Infrastructure project like underground trains and big building seem to have access to historical flooding data, and they build to the once in 50/80/1-200 years event with margin of +0.9-1.5meters, so there must be topographical map at the Amphur/Local Government, how up to date that is, and how much land has sink since the map was made is probably wise to check for sure. they probably use gps in their total station for the big projects.  

[Gandtee]

A waste of time. My house was fine for years, with rain from the local mountain escaping to a creek downstream. Then my neighbour built a wall, blocking off the run off. My bungalow is flooded periodically. There's nothing I can do about it. No laws to prevent this sort of thing here.????

[moogradod]

16 hours ago, Gandtee said:

A waste of time. My house was fine for years, with rain from the local mountain escaping to a creek downstream. Then my neighbour built a wall, blocking off the run off. My bungalow is flooded periodically. There's nothing I can do about it. No laws to prevent this sort of thing here.????

I am really sorry for you. I am sure you have investigated all possibilitites of legal action you could take. In other countries I know this would end up in the court and there would be a pretty good chance that your nice neighbor would have to remove his wall which does damage YOUR property - let alone pay compensation for the damage already made in the past. As always maybe a matter of who has the better lawyer. If everything fails - can you not conclude an agreement that you pay for some drainage in his wall (some pipes penetrating the wall or similar ?) This would be unfair, but (maybe) at least help you. Or then if water covers your property is there no way to redirect it back to HIS land ? If he can and may build a wall so can you....

 

But thanks for the advice.