I need specific statistics concerning the water in the hudson river. things such as discharge, elevation ect.?

Question

I need help on my homework and google just doesnt cut it. I need the answers from people who know their stuff goin into this sort of thing. My first and foremost question is how high is the elevation in new york city harbor?
also how do i calculate gradient?
whats the elevation of albany?
what was the length of the hudson at the end of the last ice age (20,000 years ago that much i figured out)
whats the deepest section of the hudson south of the troy dam?
how far up river do the tides reach on the hudson?
how far up river does the salt water reach?
what are the average tidal differences?
whats the approximate discharge rate of the hudson into the atlantic and i need data on the discharge of mississippi and amazon rivers as well.

if any of these questions can be answered even just 1, it will be very helpful. and ill be able to finish my hw with this data.

if anybody here could either answer me or even just give me extreamly useful links it would be EXREAMLY helpful.

Answer 1

For discharge data on the Hudson River visit
water.usgs.gov You may be able to find discharge data on the Amazon and Mississippi also.

The gradient is the slope of, in this case the river. The gradient between two points on the river is the differences in elevation of the river bottom of the two points divided by the length (reach) of river between them. It is generally possible to get these elevations from a topographic map by using the contour lines.

To find the elevation of Albany one way is to look at a topographic map of the Albany area. If you look at the city of Albany on the map there should be an elevation given near the center of the city.