[Requests] Comments on WaterML2.0 part 2 (15-018)

Satoshi Yamaguchi satoshi.yamaguchi.qj at hitachi.com
Fri May 8 02:28:24 EDT 2015

1. Evaluator:
Satoshi Yamaguchi
Hitachi Power Solutions Co., Ltd.
Phone: +81-3-5297-0511
E-mail: satoshi.yamaguchi.qj at hitachi.com

Yoshito Kikumori
National Institute for Land and Infrastructure Management, 
Ministry of Land, Infrastructure, Transport and Tourism, Japan
Phone: +81-29-864-3052
E-mail: kikumori-y92ta at nilim.go.jp

*The corresponding author is Satoshi Yamaguchi.

2. Submission: 
OGC WaterML2.0: part 2 - Ratings, Gaugings and Sections candidate 
standard (15-018)

1. Requirement #1: unit of measure for discharge should be m3/s
2. Implementation Specification Section number: examples/collection-
3. Criticality: minor
4. Comments/justifications for changes:
We found that cumecs are used as a unit of measure for discharge in 
examples/collection-example.xml (written as <swe:uom code="cumecs"/>). 
swe:uom is requred in OGC SWE Common Data Model Encoding Standard 
defines as follows: 
Req 64. The UCUM code for a unit of measure shall be used as the value 
of the "code" XML attribute whenever it can be constructed using the 
UCUM 1.8 specification. Otherwise the "href" XML attribute shall be used 
to reference an external unit definition.
We could not find cumecs in UCUM code list, but we found m/3 in Table 26 
in UCUM specification (http://unitsofmeasure.org/ucum.html). If we 
correctly understand, m3/s should be used instead of cumecs.

1. Requirement #2: example of SectionObservation should be indicated
2. Implementation Specification Section number: 8.5.3
3. Criticality: minor
4. Comments/justifications for changes:
We could not find any examples of SectionObservation in the examples 
folder. We hope that xml files indicating usage of SectionObservation 
are added to the examples folder. 
Also, we would highly appreciate it if you answer the following our 
questions and describe the answers into the specification document. 
1) In our nation, a cross section data is stored in a csv file and 
described as a 2-dimensional line string. The coordinate of each point 
is (distance from left bank in meter, elevation in meter). The precision 
of each point is (0.01m, 0.01m). In this case, calculating the area of 
the cross section is straightforward. We are not sure that we can 
calculate correct area from the representation of a cross section in 
WaterML 2 part 2, which uses GM_MultiPoint. 
2) We think that our representation of cross section is one of numerous 
approaches to defining the coordinates for a cross section geometry. 
Jackson and Maidment [2014] listed coordinate systems for river cross 
sections (see Section Coordinate systems in their paper). Our 
abovementioned representation is refereed as station-elevation sections 
express. We are not sure that the target of WaterML 2 part 2 is a part 
of these coordinate systems and future extension of this specification 
is possible to express other coordinate systems.
Jackson, S. R. and Maidment, D. R.: RiverML: A Harmonized Transfer 
Language for River Hydraulic Models, CRWR Online Report 14-5, 2014.

---- ---- ---- ---- ---- ----
Satoshi Yamaguchi, Ph.D.
satoshi.yamaguchi.qj at hitachi.com
Engineer, Information Systems Dept.
Hitachi Power Solutions Co., Ltd.
  2-2, Kanda Tacho, Chiyoda, Tokyo 101-0046, Japan
  Tel: +81-3-5297-0511

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