Classifying streams on the basis of elevation above mean sea level- A universal approach

摘要

Till date, more than 20 different stream classification systems have been proposed and yet none of them have been accepted universally. Here, we introduce "elevation above mean sea level" as the new universal stream classifying parameter. 873 field values describing hydraulic geometry of UK, USA and Canadian streams were compiled and divided into 5 distinct elevation zones. Modal and most probable values (MPVs) of aspect ratio (Ar), channel slope (Sc) and sinuosity (P) occurring concurrently in nature were calculated for each of the 5 elevation zones. Ar initially increased while moving upstream and then decreased above 5000 ft. Sc always exhibited an increasing trend with elevation. P showed high values only at 0-250 ft range and for all other zones was observed to be fairly constant. When datasets of sandy, gravel and cobble streams were divided separately into these 5 elevation zones, similar behavior was observed in the MPVs of Ar, Sc, and P for each stream type.