New answers tagged hydrology
Unfortunately there is no monosemantic translation of the term "upstream" into my native language, so probably I just can't get you right. But if "upstream" is an adjective in your context and if you mean that it characterize the situation that tributary is lying "upper" then the main river, I think that there is no much sense in this expression. Firstly, ...
Any answer is going to be semantic in nature - your definitions of upstream, tributary, network, etc. are going to dictate the answer. From a network (continuously connected features) point of view, I'm going to go with there is no difference and you cannot have a water body upstream of another without it being tributary. If you do have one that isn't ...
The National Hydrologic Dataset offers all hydrology data in 1:100,000 (medium res) or 1:24,000 (high res) for all of the US.
The US Census has several files of different resolutions of just the state boundaries, for free here - http://www.census.gov/geo/maps-data/data/cbf/cbf_state.html
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