Recently, though, its population has crashed. The humpback chub, for example, thrived in the rust-red waters of the Colorado. This lack of flooding has harmed local wildlife. Even that has not been much use as those tributaries are not powerful enough to distribute the sediment in an ecologically valuable way.ĭ. However, in the four decades since the building of the Glen Canyon dam, just upstream of the Grand Canyon, the only sediment that it has collected has come from tiny, undammed tributaries. These floods infused the river with sediment, carved its beaches and built its sandbars.Ĭ. Every eight years or so, that figure rose to almost 3,000 cubic metres. Spring Snow from as far away as Wyoming would melt and swell the Colorado river to a flow that averaged around 1,500 cubic metres (50,000 cubic feet) a second. By Thursday March 6th it was running at full throttle, which was expected to be sustained for 60 hours.ī.Floods once raged through the canyon every year. That is why a man-made torrent has been surging down the Grand Canyon. Rivers 一 and the ecosystems they support - need floods. And a similar revelation is now dawning on hydrologists. But foresters have learned that forests need fires to clear out the brushand even to get seeds to germinate. The flow of rivers is regulated by weirs and dams. People have, therefore, always sought to control them. While riverine flood damage can be eliminated by moving away from rivers and other bodies of water, people have traditionally lived and worked by rivers because the land is usually flat and fertile and because rivers provide easy travel and access to commerce and industry.Ī.FIRE and flood are two of humanity’s worst nightmares. Floods often cause damage to homes and businesses if they are in the natural flood plains of rivers. Continued abuse of our services will cause your IP address to be blocked indefinitely.BEST IELTS Academic Reading Test 13 ACADEMIC READING TEST 13 READING PASSAGE – 1įloods can occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. Please fill out the CAPTCHA below and then click the button to indicate that you agree to these terms. If you wish to be unblocked, you must agree that you will take immediate steps to rectify this issue. If you do not understand what is causing this behavior, please contact us here. If you promise to stop (by clicking the Agree button below), we'll unblock your connection for now, but we will immediately re-block it if we detect additional bad behavior. Overusing our search engine with a very large number of searches in a very short amount of time.Using a badly configured (or badly written) browser add-on for blocking content.
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