Converting a NEXRAD Rainfall Map into a Flood Inundation Map by ...

As opposed to HEC-DSS, the Arc Hydro definition for variables type isquite flexible. It is up to each user and project at hand that the variable types areestablished with basically no restrictions on the notation itself.Table 4.3: Arc Hydro Recommended Data Parameter NotationThe HEC-DSS system of the other hand, recommends the use of a variabletype notation that is as abbreviated and unique as possible capable of defining thesubtype of variable type. For instance, the PRECIP-CUM variable type notationnot only defines the variable type as precipitation but also that the valuescorrespond to the total depth fallen at the end of each time interval. In turn, theArc Hydro system allows for a non-abbreviated notation (Variable field equal toRainfall in this case) and leaves the subtype definitions for the other descriptors(the TSDataType field descriptor equal to Cumulative in this case).These differences in approach come from the philosophy and structure ofthe systems. HEC-DSS storage and retrieval efficiency relies on the uniquecomposition of the pathname parts to rapidly identify the needed record. Toaccomplish this, distinguishing naming convention at all levels (pathname parts)promotes a faster retrieval of data records by empowering a filtering search127