Clarify channel network and hydrographic.

[dblodgett-usgs]

We have a hydrographic network and channel network.

The hydrographic network is said to use the channel network as a connecting system.

Channel is said to be: watercourse which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water.

Where I'm struggling is with how channel relates to the flowpath representation of catchment. Considering that the flowpath has been said to be the shape of the river reference system, in that case, it could be the same thing as a channel.

It seems that if the HY_Network -> HY_ChannelNetwork is an aggregate of 1 HY_Channel then the (1) HY_Channel would be a HY_FlowPath. Do we need to make some association between the HY_FlowPath and HY_Channel classes?

Continueing this line of thinking to multi-scale collections of catchments, a collection of HY_FlowPaths that are each unique to a catchment at one scale could form the HY_Network representation of a catchment which is a HY_CatchmentAggregate made up by the HY_FlowPaths.

I think most of the model is ok given this observation, but I worry that HY_Channel and HY_FlowPath are going to be confusing and potentially duplicative.

In the case that a person has a 'reach catchment' as described by @darctur in Orleans, the HY_Channel and HY_FlowPath are the same, this will be a very common use case and we need to make sure we are clear on how it maps to the model.

[dblodgett-usgs]

Assigning to you @IrinaDornblut - looking for response on this. If there are changes to the model, or just informative comments that are needed, you will be responsible. Once we've concluded the conversation, we will need to make sure this is clarified in both the informative and normative section of the spec.

[IrinaDornblut]

The HY_Network is introduced as high-order network which in its entirety represents a catchment. This allows hydrologic features participating in a particular network to be logically connected, i.e. it describes the (hydro)Logic of networks typically used to display hydrology. Special network are defined with respect to the scientific concerns hydrology, hydraulic engineering and water observation refers to. – The special networks describe how features are related in the network that entirely represent a catchment, whereby the feature parts carry typical associations allowing to locate them in the network of catchments via a reference point which is outfall of a corresponding catchment (like any point on land surface). – The Network (representation) does not belongs to the topological network of catchments built from linear represented catchments between inflow and outflow nodes (even if the result may look similar to a blue-line network data product exposed by a map service.

To hydrologically describe the network concepts in common use in hydrology, special networks are defined as aggregates, whereby each component is part of only one aggregate. The components are named general as “part” to allow mapping to application-specific terms , e.g. water bodies of flowing water are logically aggregated in the hydrographic network as well as some bodies of stagnant water. Note that “water body” term refers to the mass of water accumulated therein, flowing or not flowing, and that a water body may consist of flowing parts and stagnant parts. (“stagnant water” in the glossary: “Water in some part of a river, lake, pool or groundwater not moving or flowing”.) - I think, in this way INSP Standing Water may realize a water body part.

The subtypes are defined one-directional from part to aggregate: i.e. many strata form the water body part, many parts the water body, many water bodies the hydrographic network, etc. This follows the core concept of HYF, that a study in hydrology will result in data, set and products which represent the unit of study, the catchment. Examples are maps of the “blue-line” network, station maps, or a morphometric map. Depending on the scientific concern, the same catchment may be multiple and differently.

Implementations may address/use one of these subtypes, or if not suitable the general network type, to relate their data product to the catchment it represents, e.g. maps displaying the network of rivers, an arrangement of channels, or a system of monitoring stations using a typical geometry type.

Summing up - HY_Channel and HY_Flowpath are not duplicates, channel is part of network (data product) that in its entirety represent a catchment (usually maps exposed in web service), and HY_Flowpath is the linear representation (geometric data) of the, maybe same, catchment.

[IrinaDornblut]

1) HY_Network is renamed to HY_NetworkCartography to better reflect what is meant: the representation (portrayal) of the catchment by cartographic map or set of layers displaying an entire hydro.. network 2) generalization of hydro..Networks is replaced by an 'visualisation' association to express that the hydrologic networks (hydrographic, channel, or hydrometric network) consisting of parts that are logically associated with the catchment, are considered to be different aspects the common unit of study (catchment) may appear depending on the scientific concern of study, and that the catchment can be portrayed by displaying these networks 3) both model changes are displayed in the catchment diagrams in latest html view

[dblodgett-usgs]

This is great. If you have time to draft the section 6 content for this, I'd appreciate it. If not, I'll get to it eventually.

[IrinaDornblut]

inline text proposal for lines 318/319, intended to describe the portrayal of catchment in maps as a typical representation of a catchment using geometric shapes. – model details will be described in section 7.4.2.1 and with the particular networks ..

[dblodgett-usgs]

The discussion related to this has moved to #47 Will close for now.