Lake Level
+7
cypress
Trailrunner
ltollefs
MexicoPete
RVGRINGO
slainte39
SunFan
11 posters
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Lake Level
I see from the lake level web page that we're now at a lake level that was not reached last year until Aug 29th.
SunFan
SunFan
SunFan- Share Holder
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Location : San Antonio Tlayacapan - Upper Chula Vista
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Re: Lake Level
The lake is always 'level', but the elevation of its surface does rise and fall. However, a purist would insist that the surface is never 'level', but actually a curved surface. He would be correct.
Not much to think about today.
Not much to think about today.
RVGRINGO- Share Holder
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Re: Lake Level
I loved your post RV. It is so true.
On a serious note, I sure hope the level keeps on going up as it has so far this year and gets the lake level a little closer to the sea walls or whatever they are called, you know closer to the top of the shore.
On a serious note, I sure hope the level keeps on going up as it has so far this year and gets the lake level a little closer to the sea walls or whatever they are called, you know closer to the top of the shore.
MexicoPete- Share Holder
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Re: Lake Level
I'd like to this...
Photo source...
http://www.eltesorodelajumentud.info/asierach.html
Photo source...
http://www.eltesorodelajumentud.info/asierach.html
ltollefs- Share Holder
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Location : Chapala
Re: Lake Level
You'd like to what this? Surf!?!
Trailrunner- Share Holder
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Re: Lake Level
Just how difficult can it be?
...I'd like to see this. Actually both the cow and the flooded pier.
...I'd like to see this. Actually both the cow and the flooded pier.
ltollefs- Share Holder
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Re: Lake Level
How is the lake level determined? About 100 years ago, they would drop a weighted line from a bridge in Ocotlan to the surface of the lake and measure the difference between the two. The bridge was arbitrarily considered to be the baseline of 100 and the length between the bridge and the water surface was subtracted from 100 to determine the level of the lake relative to the bridge. So if the difference between the bridge and the water was 5.00 meters, the lake level was considered to be 95.00. Well, the bridge is long gone and there now are more sophisticated ways to measure the level of the lake. However, in order to maintain continuity of records over the past 100 years, the old arbitrary baseline and relative level of the lake to that baseline has been retained.
Smartalex- Share Holder
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Re: Lake Level
Smartalex
Was that a bridge over the Santiago river that eventually flows out to the Pacific?
SunFan
Was that a bridge over the Santiago river that eventually flows out to the Pacific?
SunFan
SunFan- Share Holder
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Re: Lake Level
SunFan, Can't answer your question. I read the historical reference a few years ago...and In Spanish. I remember wondering, like you, exactly where this bridge might have been located.
Smartalex- Share Holder
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Re: Lake Level
Yes, the old bridge that was the nearest to the source or the outlet from the lake that was the start of the Rio Santiago. On the old road to La Barca, that was changed a little some years ago.SunFan wrote:Smartalex
Was that a bridge over the Santiago river that eventually flows out to the Pacific?
SunFan
slainte39- Share Holder
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Re: Lake Level
Level has two quite different meanings.RVGRINGO wrote:The lake is always 'level', but the elevation of its surface does rise and fall. However, a purist would insist that the surface is never 'level', but actually a curved surface. He would be correct.
Not much to think about today.
cypress- Share Holder
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Re: Lake Level
Smartalex wrote:How is the lake level determined? About 100 years ago, they would drop a weighted line from a bridge in Ocotlan to the surface of the lake and measure the difference between the two. The bridge was arbitrarily considered to be the baseline of 100 and the length between the bridge and the water surface was subtracted from 100 to determine the level of the lake relative to the bridge. So if the difference between the bridge and the water was 5.00 meters, the lake level was considered to be 95.00. Well, the bridge is long gone and there now are more sophisticated ways to measure the level of the lake. However, in order to maintain continuity of records over the past 100 years, the old arbitrary baseline and relative level of the lake to that baseline has been retained.
There are 3 (now maybe only 2) weather stations on the lakeshore where the level is measured daily. They relate the lake level to the old measurement at that bridge.
Last edited by cypress on Wed Jul 11, 2018 6:58 am; edited 1 time in total (Reason for editing : clarity)
cypress- Share Holder
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Re: Lake Level
Yes, it has risen more that half a meter this season.SunFan wrote:I see from the lake level web page that we're now at a lake level that was not reached last year until Aug 29th.
SunFan
cypress- Share Holder
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Re: Lake Level
Yes. But that part of the Santiago flows nowhere now.SunFan wrote:Smartalex
Was that a bridge over the Santiago river that eventually flows out to the Pacific?
SunFan
cypress- Share Holder
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Re: Lake Level
If you are referring to overflow from the lake, that rarely ever happens. just rainy season runoff and tributaries below that outlet source.
slainte39- Share Holder
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Re: Lake Level
The last time water flowed out of the lake was over 40 years ago. In Nayarit where the Santiago river enters the Pacific it is quite large-from streams that enter it along the way.slainte39 wrote:If you are referring to overflow from the lake, that rarely ever happens. just rainy season runoff and tributaries below that outlet source.
cypress- Share Holder
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Re: Lake Level
SunFan: They use a more modern method to determine lake level lake now but the baseline of 100 remains the same whether or not the bridge still exists or whether or not there is outflow to the Rio Santiago. Reread my first post in this thread. I think this is clearly stated.
Smartalex- Share Holder
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Re: Lake Level
Cypress: I believe the weather stations you are referring to get their information on the level of the lake from the governmently agency that actually does the measurement. I believe there is a weather station, maintainèd. by that same agency, on Scorpion Island that reports the lake level continuously, probably by monitoring a tethered bouey floating on the lake surface.
Smartalex- Share Holder
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Re: Lake Level
I've been to the weather station near me. They have a physical setup to measure the level of the lake-a metal catwalk out into the lake and a ladder down to the vertical measuring board with a metric scale that is based on the 100 baseline. It is a government agency that does this. Maybe that has changed?
cypress- Share Holder
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Re: Lake Level
That's interesting. Where is this station located? Do they have a website? I'm referring to the government-operated site which had a link posted on the now-closed Chapala Weather site. You could actually watch the lake level rise and fall slightly from moment to moment, as if it were monitoring a bouey floating on the surface. I'll see if I can find the site again and post the link to it here.
Smartalex- Share Holder
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Re: Lake Level
https://www.ceajalisco.gob.mx/contenido/chapala/
Smartalex- Share Holder
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Re: Lake Level
Smartalex wrote:
https://www.ceajalisco.gob.mx/contenido/chapala/
That is the same government agency that runs the weather sites.
Piedra Barrenada
Last edited by cypress on Wed Jul 11, 2018 7:52 pm; edited 1 time in total (Reason for editing : an addition)
cypress- Share Holder
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Re: Lake Level
Smartalex wrote:That's interesting. Where is this station located? Do they have a website? I'm referring to the government-operated site which had a link posted on the now-closed Chapala Weather site. You could actually watch the lake level rise and fall slightly from moment to moment, as if it were monitoring a bouey floating on the surface. I'll see if I can find the site again and post the link to it here.
It's not a buoy effect... look at the dates under the heading. About 3 or 4 days worth that keep changing. The highest level is the most recent "todays" level. The lowest is from three or four days ago. It's the same effect that you get when watching the weather satellite in a loop.
ferret- Share Holder
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Re: Lake Level
ferret I think you are right. That information and the weather sites come from CONAGUA. Now they show that the level has gone up 67 centimeters.
Last edited by cypress on Wed Jul 11, 2018 8:32 pm; edited 1 time in total (Reason for editing : additional information)
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