1-01-05 new entries and revision for hydrology domain

[jbianchi81]

Summary and Purpose

To revise existing and add new terms useful for hydrology.

Stakeholder(s)

The hydrological community, WHOS

Proposal

Final Update 9 June 2022

REVISE

Notation	Name	Description
165	Groundwater Ground water  (amount per unit area)	Amount of water present beneath the ground surface per unit area.
166	Groundwater level Ground water (level)	Elevation of the water table or piezometric surface of an aquifer at a certain location and time. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
168	Lake level	Elevation of water in an inland body of surface water of significant extent. [Based on 'water level' and 'lake' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]Map of the height of the lake surface.
171	StreamRiver discharge	Volume of water flowing through a river (or channel) cross-section per unit of time. [Based on 'discharge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
172	Stream level River stage (level  above reference)	Elevation of the free water surface of a water body flowing in an open or closed conduit. [Based on 'water level'and 'stream' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
527	Soil moisture (in the roots region)	FractionalSub-soil 3D field of the fractional content of water in a volume of wet soil. Typically, in a layer from the surface down to approximately 3 meters3m.

NEW

Notation	Name	Description
12247	Stream velocity	Ratio of the distance covered by a body of water, moving in a specified direction, to the time taken to cover that distance. [Based on ‘velocity’ in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12248	Stream mean velocity	Velocity at a given cross-section of a stream, obtained by dividing the discharge by the cross-sectional area of the stream at that section. [Based on 'mean velocity' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12249	Stream surface velocity	Velocity of a liquid at its surface at a given point. [Based on 'surface velocity' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12250	Index velocity	Velocity measured along a direction across the stream (acoustic principles) or over the water surface (radar, image velocimetry). [Based on 'velocity index method' in Manual on Stream Gauging (WMO-No. 1044), Volume II. 2010.]
12251	Water surface slope	Difference in the stage of water surface over a short stream reach. [Based on 'water surface slope' in Manual on Stream Gauging (WMO-No. 1044), Volume II. 2010.]
12252	Water level	Elevation of the free water surface of a water body relative to a reference datum (synonym: stage, gage height). [Based on ‘water level’ in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12253	Percolation rate	Flow of a liquid through an unsaturated porous medium, such as that of water in soil under the effect of gravity for a unit time. [Based on 'percolation' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12254	Recharge rate	Natural or artificial introduction of water into the saturated zone of an aquifer for a unit time. [Based on 'groundwater recharge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12255	Aquifer volume	Volume of geological formation capable of storing, transmitting and yielding exploitable quantities of water. [Based on 'aquifer' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12256	Hydraulic conductivity	Property of a porous medium which, according to Darcy's law, relates the specific discharge to the hydraulic gradient. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12257	Hydraulic transmissivity	Rate at which water is transferred through a unit width of an aquifer under a unit hydraulic gradient. [Based on 'transmissivity' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12258	Porosity	Ratio of the volume of the interstices in a given sample of a porous medium to the gross volume of the sample, inclusive of voids. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12259	Effective porosity	Volume of the void spaces through which water or other fluids can travel in rock or sediment, divided by the total volume of the rock or sediment. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12260	Specific retention	Amount of water held in the soil after gravitational water has drained away expressed as a volume percentage. [Based on 'specific retention' and 'field capacity' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12261	Infiltration rate	Flow of water through the soil surface into a porous medium for a unit time. [Based on 'infiltration' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12262	Infiltration capacity	Maximum rate at which water can penetrate the soil matrix per unit area under certain conditions. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12263	Specific capacity (well)	Ratio of discharge of a well to drawdown at equilibrium. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12264	Specific yield	Ratio of the volume of water which can be drained by gravity from an initially saturated porous medium to the total volume of the porous medium. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12265	Groundwater flow	Volume of groundwater flowing along an aquifer per unit time. [Based on International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12266	Storage	(1) Impounding of water in surface or underground reservoirs for future use. (2) Volume of water stored. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12267	Total dissolved solids	The concentration of all dissolved substances in water, usually expressed in milligrams per litre, which would remain as a solid residue after removal of the water. [Manual on Water Quality Monitoring (WMO-No. 680). 1988]
12268	Suspended sediment	The component of an unacidified water sample that is retained by a 0.45-nm membrane filter. [Manual on Water Quality Monitoring (WMO-No. 680). 1988]
12269	Suspended sediment discharge	Rate of movement of sediment which is suspended by turbulence in flowing water for considerable periods of time without contact with the bed transported at a given cross-section. [Based on 'suspended sediment' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12270	Sediment discharge	Rate of movement of sediments in a stream at a given cross-section. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12271	Bed load discharge	Amount (weight, mass or volume) of sediment that moves on or near the streambed by rolling, sliding, or saltating (bed load) transported through a cross-section of a stream per unit time. [Based on 'bed load discharge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12272	Suspended sediment load	That part of the total transported sediment which is suspended by turbulence in the flowing water for considerable periods of time without contact with the stream bed, moving with almost the same velocity as the flowing water and generally expressed in mass or volume per unit of time. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12273	Total sediment load	Total quantity of sediment passing through a reach, both in suspension and along the bed, excluding the sediment deposited on the bed within the reach. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12274	Runoff	That part of the precipitation which flows towards a river on the ground surface (surface runoff) or within the soil (subsurface runoff or interflow). [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12275	Runoff coefficient	Ratio of runoff depth to precipitation depth. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12276	Depth of runoff	Runoff volume from a drainage basin, divided by its area, in a specified time. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12277	Soil moisture	Percentage of water in soil expressed relative to dry-soil weight or by volume.Synonym: water content of soil. [Based on 'soil moisture content' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12278	Live storage	Volume of water in a reservoir between the minimum and maximum water levels under normal operating conditions. Synonyms: usable storage, active storage, available storage capacity. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12279	Reservoir storage	Volume of a reservoir including dead storage. Synonym: total storage. [Based on 'total storage' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]
12280	Lake volume	Volume of water contained in a lake at a given water level. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]

Update Jun 1 2022
Adjusted reference to recommendations

Update May 18 2022
Fixed columns order
Uploaded into new branch

Update 11 May 2022
Removed references URLs. Added notations to new codes. Ordered by notation

Update 28 Apr 2022
Changed "soil moisture content" to "soil moisture"

Update 17 Feb 2022
This list was submitted to HCP and shared within JET-HYDMON for feedback from the hydrological community. It contains basic variables observed in hydrology, excluding water quality variables. All descriptions are cited from official WMO documents

Reason

[your reasoning why the proposal resolves the issue]

[amilan17]

@juan - reach out to team members to discuss these particular questions

[jbianchi81]

1-01-05 hydrological domain - draft.ods
Here is a list of revised and proposed terms for observed variable - hydrological domain. A thorough revision is needed, plus some terms are missing a description and more tags might be added. Since most of the terms are common with other domains (specially Ocean) it would be desirable count with the collaboration of other team members, perhaps @anthoninlize ?

[rodicanitu]

I recommend that prior to submission/any further review, there is a review of whether these are indeed new terms, or already in the code lists; could this review be a necessary step prior to initiating a new item? it may make for a more efficient review process, especially when the list is long.

[amilan17]

@jbianchi81 will work with Johanna Karhonen and JET-HYMON to finalize proposal. It may not be ready for FT22-1.
and Charles Fierz.

[jbianchi81]

An expert team of hydrologists has been formed to finalize the proposal. The goal is to deliver a reduced list of non-controversial terms for FT22-1, and then to continue working on the rest.

[jbianchi81]

Proposal updated (see first comment)

[amilan17]

This proposal looks well thought out. It would be helpful to organize into 3 tables. 

• New
• Revision
• Deprecated/Superseded

[JohnEyre]

These are the variables exisiting already in WMDR containing the words "soil" or "lake", for which there are potential conflicts with the new proposal:

• 527 Soil moisture (in the roots region)
• 528 Soil moisture at the surface
• 246 Soil type
• 596 Soil temperature
• 245 Soil heat flux
• 167 Lake area
• 168 Lake level
• 410 Lake surface temperature
• 725 Lake ice \ Ice thickness

[jbianchi81]

Branch updated. The first column indicates whether it is a revision, addition or keeping of an existing term

[JohnEyre]

There is a likely conflict between the new proposed variable

• soil moisture content
  and the existing variables:
• 527 soil moisture (in the roots region)
• 528 soil moisture at surface
  Potential conflicts in the variable names and definitions and units.

[jbianchi81]

@JohnEyre -- We discussed this in the last meeting, saying that we are moving towards a more atomic model in which the geometry should be excluded from the variable name (and should be specified using the geometry property). But during the transition both approaches may coexist (the new one would be a broader concept that encompasses the two old ones).

[JohnEyre]

@jbianchi81 -- I agree. But in the meantime, I suggest we should try to keep all the soil moisture variables as consistent as they can be. Given the existing variables (at the surface, and in the root region), which layer is the new proposed variable representing? Is it the avrage soil moisture in a (thicker) layer. If so, which layer? Also can we drop "content" from the name? (They are all "soil moisture contents" but the word "content" appears to be redundant. Also note the difference in units, which should be avoided if possible.

[joergklausen]

Entries 527 and 528 appear to cover the soil moisture for the entire soil region (it would appear that 528 is included in 527). So I question @jbianchi81 if a new variable 'soil moisture' is even needed at this point. If indeed so, I agree with @JohnEyre that 'content' can be dropped.

The description of 527 should be revised IMHO by removing '3D field of the'. There may be a requirement for 3D field listed in OSCAR/Requirements, but more generally, observations of 'soil moisture' can in principle be of geometry point, profile, area or volume.

@jbianchi81 Please add definitions to existing elements where they are missing.

[JohnEyre]

I agree that "3D field" is wrong - both 527 and 528 are, by implication, 2D fields although this does not need to be stated in the definition. From the perspective of OSCAR/Requirements, these are separate 2D fields - one "in the roots region" and one higher up ("at surface"). The vertical location of each is a little imprecise, and I could take this issue back to users if you wish.

[jkorhonen]

I did an initial consistency check for hydrological variables.

There was two stylistic ways to express groundwater; groundwater and ground water - > should be coherent way?
I would suggest 165 Ground water area -> Groundwater area

Some first letter lower case ->Upper case issue suggestions to be coherent:
171 stream discharge -> Stream discharge
12247 stream velocity -> Stream velocity
12248 stream mean velocity -> Stream mean velocity
12276 depth of runoff -> Depth of runoff
12280 lake volume -> Lake volume

And for consistency to avoid commas in variable names
and 12249 Surface velocity, stream -> Stream surface velocity

12266 Storage is linked in path to ground water, but definition includes surface water aspects as well.

I will have one more look when @jbianchi81 has updated the table.

[jbianchi81]

@jkorhonen -- Thanks for the revision. I updated the table in the issue summary to inform which entries are being edited or added. Please proceed to introduce your suggested changes concerning stylistic consistency.

[joergklausen]

I support 'groundwater' in one word. Also 'Stream surface velocity'.

[jkorhonen]

@joergklausen I do not have any additional points to raise in addition to stylistic things mentioned earlier. Consistency check done on my side.

[amilan17]

1. Are these names correct? 
   1. 12256, Hydraulic conductivity (K) 
   2. 12257, Transmissivity (T)
   3. Porosity (φ or n)
2. see question about citing references in 5-02-05 Methods for Terrestrial domain - new terms for hydrology #281 (comment)
3. tags/paths are inconsistent, but this is not critical immediatly

[jkorhonen]

@amilan17 @jbianchi81

1. Names are correct, however we could leave out letter/symbols (in brackets) since not all variables have them.
2. I noticed the same, but was not sure is it worth mentioning/critical

[amilan17]

https://github.com/wmo-im/wmds/wiki/2022-05-31-TT-WIGOSMD-23 notes:

• ok to remove (xyz) from names
• @amilan17 define text for different types of references (based on...[pub], etc)
• @jbianchi81 update branch within two days (if possible!) and tag Joerg for validation

[jbianchi81]

@joergklausen -- branch updated.

[joergklausen]

Please see #281 for agreed syntax. @amilan17 agreed to do the final clean-up of the branch.

[jbianchi81]

@joergklausen -- branch updated.

[amilan17]

@joergklausen please validate

[joergklausen]

@amilan17 Branch validated, I couldn't find anything wrong.

[amilan17]

ready for FT