In Sinha and Mark et al’s paper, “An Ontology Design Pattern for Surface Water Features”, the authors works together to introduce Surface Water pattern, in order to generalize and standardize the semantics of basic surface water related features on earth’s surface. Their incentive to create this model is to resolve the differences of semantics description around the world, on describing surface water related feature and terrain. To bring convenience and precise description on surface water features are the essence of their work.
In the Surface Water pattern, they divided Earth’s surface water system into two parts: Dry module and Wet module. The Dry module, which they used to describe the landscape that is able to contain water body/flow, contains: Channel, Interface, Depression. Channel describes the landscape that allow water to flow, tend to have two ends (start/end point), which they latter describe as Interface. Interface is where channel start and end, and if the Interface include interaction with other surface water related landscape (e.g. another Channel or Depression), it is a Junction (subclass). And depression, they describe as a landscape that can contain water body, so it does not over flow. It is usually surround and enclosed by a rim (which is usually a contour line represents the highest elevation of the depression).
The Wet module is about actual water (or in their further discussion, to be any liquid has the capability to flow) body/flow. It includes Stream Segment, Water Body, and Fluence. Stream Segments represents water flow in Channel (from the Dry module), which has only one start and end point (later explained as Influence and Exfluence), which is not necessary the Interface for the Channel it flows within. Water Body is the water that sit relatively still inside Depression (from the Dry module). It is also included by the rim of Depression. Fluence describes the start and end point of Stream Segments. If it is the start point of Stream Segments, it is called an Influence. Otherwise, it is called an Exfluence. If it is where one Stream Segment interact with another Stream Segments or Water Body, it is a Confluence.
And the end. Sinha and Mark et al explained that the Surface Water pattern did not cover every features that needs to be describe as part of Earth’s surface water system, such as features related to glaciers and ice flows. It rather serves as a frame work that can be extended, and further developed to more specific Ontology. And the Surface Water pattern should be describing basic features for all flowing liquid including water, and on all planet with gravity.
My major critics on their Surface Water pattern is: although they said Wetland (as an important feature in surface water system) may not be described using their pattern in the discussion part, it is not proper to call their Onotology design as “Surface Water” when they clearly excluded wetland as a necessary part of Earth’s surface water system. The reason I claim that it is a major flaw for excluding wetland in their Surface Water pattern is: wetland in Dry module, neither fits their definition for Depression (since wetland not necessarily have a rim), nor can be described as a series of Channel (it does not have to contain flowing water). Even though in their discussion of their Onotology pattern, they stated that wetland can be developed in a different Ontologiy pattern or future extension of this pattern, it still creates confusion when they name their pattern as Surface Water but not including all parts of surface water.