What is "NADD" in Groundwater Level?

[BobbyBear]

Hi,
I was reading a geotechnical report, and there is a sentence that says:

"the groundwater level on site was identified at depths ranging from +1.50m NADD to..."

does anyone know what NADD is?

Thank you very much!

 

[JaredJames]

Nothing shows up on a search, could you link to the report?

 

[BobbyBear]

Hi, thanks for looking into it!
It is the "GEOTECHNICAL INVESTIGATION
CONSULTANCY SERVICES FOR THE MASDAR DEVELOPMENT
ABU DHABI, UNITED ARAB EMIRATES ", sorry I cannot share this online as I don't have permission to do so.
It uses NADD continuously, for example, when talking of soil startification,
"The superficial deposits are generally represented by coarse grain sedimentary sequences of diverse origin. The upper unit (GL down to +2.00 mNADD) ..."
or
"The chemical analysis over the soils/water collected in the field shows that the horizon from +2.00mNADD to -0.40mNADD can generally be described as sabkha. "

There are also bedrock elevation contour maps with elevation values in m NADD.

 

[JaredJames]

Have you checked the front / back of the paper to ensure there isn't an index describing these terms.

The first instance of useage should highlight the abbreviation to you, so it may be worth starting to read through again.

Aside from that, as above there's nothing in the search so I can't provide any further help.

 

[BobbyBear]

No, I only have the extract that was sent to me;
however I will ask them if there is such an index,
thanks for your help, if I find out what it is I'll let you know.

 

[BarnRat]

I found many hits from an internet search of "NADD" but most are for:

the National Alliance for Democracy & Development in The Gambia (NADD)

and that can't be right . . . .

 

[Studiot]

Sea level varies over the globe and the chosen value and relation to the chosen geoid defines what is called is called datum. This is used for level (height or depth) information in cartography.

The last D stands for Datum, which is the local sea level used in that part of the world. I expect N stands for national. So I would guess NADD stand for National Abhu Dahbi Datum.

It is a while since I was out there but I suspect this is the datum referred to

http://www.asprs.org/resources/grids/10-2007-bahrain.pdf

see also

http://answers.yahoo.com/question/index?qid=20080613103918AAeJJnq

"The chemical analysis over the soils/water collected in the field shows that the horizon from +2.00mNADD to -0.40mNADD can generally be described as sabkha. "

This is a most interesting material - I have a few fishermen's tales to tell from my time out there.

go well

 

[BarnRat]

It also shows up here (undefined) in this article:

http://www.cebarco.com.bh/completed_projects_details.asp?id=29&type=0

Excavation of the turn area to a depth of -7.34m NADD.

Dredging of the existing channel to a level of -7.34m NADD.

 

[BobbyBear]

Hello all,

thanks for your inputs!
And yes, I asked them to look for an index and it turns out that ADD does stand for Abu Dhabi Datum, so probably as Studiot said, NADD = National Abu Dhabi Datum.

Thanks a lot! XD

 

[Phobos]

In the US, we often measure elevation with respect to a NGVD (National Geodetic Vertical Datum).