My question is what is gorge in a river
131581
a deep ravine (usually with a river running through it) \ndefile: a narrow pass (especially one between mountains)
621015
no, there are many freshwater rivers that are tidal.  in fact, i dont think i know of any rivers that arent freshwater (except polluted one)\n\nmany rivers that empty into the ocean would be considered tidal.\n\nwhere it empties, as the tide rises, water will rise too, and in many instances can change the current of the river and make it flow in reverse.  \n\nif you close up that opening a little, say with a bridge, the water will flow extra fast and is a very interesting ride on a canoe or kayak.  its a popular attraction at many places in maine i know, where you can ride around in the rapids that form on one side of the bridge and then slowly transitioning into rapids on the other side.
87568
From those choices the finest particles would have to be found near the mouth. This is because along the course of a river the speed of the river varies and at the mouth is generally the slowest point. As it enters the ocean it is likely to be flowing at its slowest speed, so its ability to carry particles is at its lowest energy level and only the very smallest particles will stay suspended. \n\nHowever, the question is not really correct with that wording and with this answer. There is no reason that the very smallest particle carried by a river cannot be found at ANY of those points along the river, and transported all the way to the mouth of the river. This also ignores the fact that rivers carry dissolved solids as well.
16119
Yes, there are also some tidal rivers.  The Danube is one I can think of.
226947
I belive you are tallking about a source for water.  It could be several thing, a glacier melting,  snow pack from the winter or natural springs.  Where the water in a mountain finds a hard rock and then will find the path of least resistance,  sometimes out the side of the mountain which would be a mountain spring.  But the mountain source is just the fact that the river is starting in mountain,  from a spring, winter melt off or glacier.  hope that helps.
111804
A current, generated by several different factors including gravity, water temperature, and the ammount of water flowing through a particular waterway: the larger an ammount of water the faster it can flow (esp. in the case of a river or a stream where the water will flow more rapidly if it is congested into a narrow, but open waterway).
510196
First off, Valley Forge is a National Park and has been since 1976 \n Other than water runoff from the parking lots, I don't see how the park could effect the river.
621962
I'm pretty sure the River he's talking about is actually the Mythical river the dead cross by ferry. The River Styx.  I myself have never read the book nor actually want to only because of experiencing personal bad vibes from a book a friend had.\n About the best I can come up with at the moment is some sites I found on the history of the Necronomicon and other info on the book. As well as info on the River Styx. Wish I could have offered more, though I'll keep looking. Maybe I'll luck out from one of my friends who has read the book and studied it intensely. Oh some of the sites are talking about the first two books of the Necronomicon, the one written by Crowley and the one written by the Mad Arab also known as Abdul Alhazred. I honestly don't know which one came first between Alhazred's and Crowley but if I remember right I think Alhazred's was the first written rendition of the Neconomicon. Anyway I supplied those links as well. Maybe one will help.
518832
The Colorado River has been dammed a lot and it's affecting the areas around it.  Is that what you mean?  Or do you mean polluted rivers?  Like, when Lake Erie caught on fire?\n\nThe Amazon is being hurt by rainforest deforestation.  Like, too much sediment running off from erosion, too much sunlight (from cutting down trees), maybe some fertilizer runoff.\n\nYeah, the Ganges is a total mess.  It's so polluted--raw sewage, industrial waste...it's disgusting.  I'd say you could find several endangered rivers in India.  \n\nTry China, too.  They probably have some endangered rivers.  Check around very industrial areas, places with stuff like nuclear plants or factories, textile or paper mills, stuff like that.
315198
A - A meander is a bendy bit of a river.\n\nC - A strange example though. A & B are physical/mechanical weathering and D is through the action of flora/forna. I'm not sure C actually happens often but it is the only chemical action.\n\nB - Limestone will dissolve in a weak acid. Another formation it produces are limestone pavements.\n\nHope this helps
333963
I don't think that it is refered to as the Congo River any longer. I think it is now called the Zaire River. \n\nAnyway, this site has a good map of it, called the Zaire River on the map.
498097
if you are going 4.5m/s then you have traveled in two directions, straight across and downstream. If you make a drawing of this it will create a triangle with 2 sides of the river and a hypotenuse of the distance traveled, 27.\nyou know one side on the river is 14, the hypotenuse is 27\nthe pythagorean theorem says that A squared + B squared = C squared for a right sided triangle\nso 14 squared + distance across river squared = 27 squared\nD squared  = 729 - 196\nd = square root of 533\nd= 23.08 \nso the distance traveled at 4.5m/s was 23.08\nwe know that d = r * t\nso t = 23.08/4.5\n\nt = 5.15 s\n\nwe also know that in 5.15s the boat went 14 m downstream\nagaing d=rt\n14 = r * 5.15\nr (speed of current) = 14/5.15\nr= 2.71m/s
64697
Gravity by itself doesn't make rivers flow.  The water cycle also plays an important part.  If it were not for the constant replenishment of reserviors of water through the water cycle, "high" areas would quickly empty of water.  Also high and low are relative terms and the force of gravity attracts mass towards the center of a massive body (in this case the earth).
647365
Dams close up a river so the water stays in one place and forms an artificial lake. Canals are water passageways that boats carrying cargo can use to move around.
128872
If you think about it, the "source" of a river is not a real thing; It's just a single spot in the water cycle. Rain falls, collects, runs into streams, runs into rivers, run to a lake or an ocean, evapourates into clouds, and goes round again.  You could argue that anywhere in this cycle is a starting point, or nowhere.  Gravity & evapouration are driving this cycle.  In the same way, winds are just air moving from an area of higher pressure to an area of lower pressure. What causes these differences in pressure is what starts the winds a-blowing.  Some of the factors involved are temperature changes in the oceans, and the friction of the atmosphere against the earth as it turns.
552000
Usually river depth and "crest" are measured from the bottom of the river at some location, say a bridge, or a piling driven into the riverbed for this purpose.\n\nCrest is the highest level the measurement reaches after it starts rising. Flood Stage is the depth at which the river begins to overflow its banks.  The location of the bank is pretty arbitrary, but always defined so as to indicate that a higher water level will damage something.
136415
It is a very long river running some 4,000 miles, through Peru and the Brazilian rain forest. The Nile in Africa is longer, but the Amazon is wider, up to 6 miles wide in places.\n\nThe Amazon has by far the greatest total flow of any river, carrying more than the Mississippi, Nile, and Yangtze rivers combined — so while it may not be the longest river, it is undoubtedly the largest. Its drainage area, called the Amazon Basin, is the largest of any river system.\n\nThe quantity of fresh water released to the Atlantic Ocean is enormous: up to 300,000 m³ per second in the rainy season. Indeed, the Amazon is responsible for a fifth of the total volume of fresh water entering the oceans worldwide. \n\nIt is said that offshore of the mouth of the Amazon potable water can be drawn from the ocean while still out of sight of the coastline, and the salinity of the ocean is notably lower a hundred miles out to sea.\n\nThe main river (which is usually between one and six miles wide) is navigable for large ocean steamers to Manaus, 1,500 km (more than 900 miles) upriver from the mouth. Smaller ocean vessels of 3,000 tons[1] and 5.5 m (18 ft) draft[2] can reach as far as Iquitos, 3,600 km (2,250 miles) from the sea. \n\nThe Amazon drains an area of some 6,915,000km² (2,722,000 mile²), or some 40 percent of South America. It gathers its waters from 5 degrees north latitude to 20 degrees south latitude. \n\nIts most remote sources are found on the inter-Andean plateau, just a short distance from the Pacific Ocean; and, after a course of about 6,400 km (4,000 mi) through the interior of Peru and across Brazil, it enters the Atlantic Ocean at the equator.\n\nThe Amazon has changed its drainage several times, from westward in the early Cenozoic Era to its present eastward locomotion following the uplift of the Andes.\n\nTIDAL BORE\n\nFollowing the coast, a little to the north of Cabo do Norte, and for 160 km (100 miles) along its Guiana margin up the Amazon, is a belt of half-submerged islands and shallow sandbanks. Here the tidal phenomenon called the bore, or Pororoca, occurs, where the depths are not over 4 fathoms (7 m). \n\nThe tidal bore starts with a roar, constantly increasing, and advances at the rate of from 15 to 25 km/h (10 to 15 mph), with a breaking wall of water from 1.5 to 4 m (5 to 12 ft) high. The bore is the reason the Amazon does not have a delta; the ocean rapidly carries away the vast volume of silt carried by the Amazon, making it impossible for a delta to grow. It also has a very large tide sometimes reaching 20 feet.