Saturday, January 3, 2015

Main Stem

The main stem of a river is the principal channel from source to mouth, the channel where movement downstream causes the Strahler stream order number to increase by increments of one. If a river has many tributaries, and if the tributaries themselves are large streams, determining which channel is the main stem or  main head-stream can be challenging as a traveler descends or ascends riverside trails. For example, suppose you were a traveler trying to go upstream on the Sidon from the local land of Zarahemla to the land of Nephi. As you came to this point, which we correlate with territory between Melek and Manti, would you correctly identify the main stem of the river?
Lacantun/Usumacinta Confluence Eye Altitude 1.44 Kilometers
Cartographers identify the main stem of a river with a thicker line on their map. We have followed this convention in the 384 streams we have plotted to date in our Google Earth repository of Mesoamerican watersheds. Imagine the difficulty, though, a traveler on the ground would have identifying the main stem of their target river in this region which we correlate with territory between Melek and Manti.
Chixoy/Salinas Confluence with the Pasion to Form the Usumacinta with
the Lacantun Confluence 42 River (17 Air) Kilometers Downstream
Is it any wonder Ammon and his 15 strong companions wandered in the wilderness Mosiah 7:4 as they attempted to navigate this cacophony of rivers? When we add in the additional streams plotted via NASA satellite remotely sensed elevation data, this landscape of approximately 12,000 square kilometers appears even more challenging.
Chixoy/Salinas Usumacinta/Lacantun Confluence Area
with Remotely Sensed Streams Plotted
Difficulty identifying the main stem of the Sidon almost certainly contributed to the traveler disorientation described in the Nephite annals.