3/17/2023 0 Comments When the river runs dry meaning![]() More fundamentally, altered flow characteristics of rivers are among the most serious problems for sustainable development, because they seriously affect the ecosystem services on which both humans and wildlife depend. For example, Mexico has long complained that it is not getting its share of the Colorado River’s waters under the terms of a 1944 water-sharing treaty with the US.Ĭhina's hyperactive dam building illustrates the high costs of river fragmentation Shared water resources are often siphoned off by upstream powers with little consideration for the interests of downstream states. The over-utilised Murray in Australia and the Indus in Pakistan are at risk of meeting with the same fate. Others that run dry before reaching the sea include the Yellow River, the cradle of the Chinese civilisation the Amu Darya and the Syr Darya – the two lifelines of Central Asia the Euphrates and the Tigris in the Middle East and the Rio Grande, which marks the entire Texas-Mexico border before heading to the Gulf of Mexico. Now, because of the upstream diversion of 9.3 billion cubic metres of water annually, the Colorado's flow into its delta has been reduced to a trickle. The river, which originates in the Rocky Mountains and is the lifeblood for the south-western United States, used to empty into the Sea of Cortez in Mexico. ![]() Such fragmentation is affecting the flow of nutrient-rich sediment from the mountains where rivers originate, riverside vegetation, the migration of fish and quality of water.įor example, the Colorado River, which is broken up by more than 100 dams and thousands of kilometres of diversion canals, has not reached the sea since 1998. Instead of flowing freely, rivers are becoming increasingly fragmented by dams and other hydro-engineering structures. Consequently, only about one third of the world's 246 long rivers can still be described as free-flowing, meaning that they remain clear of dams and other man-made diversions. Yet, according to another study published in this month's Nature journal, humans have modified the flows of most long rivers, other than those found in the remote regions of the Amazon and Congo basins and the Arctic. ![]() If the world is to avert a thirsty future and contain the risks of greater intrastate and interstate water conflict, it must protect freshwater ecosystems, which harbour the greatest concentration of species. ![]() Water sustains life and livelihoods and enables economic development. According to the study's summary of findings, released last week: "Nature across the globe has now been significantly altered." Owing to excessive damming and drastic overuse of water resources, an increasing number of rivers are drying up before they reach the sea.Ī new United Nations study offers grim conclusions: human actions are irremediably altering rivers and other ecosystems and driving increasing numbers of plant and animal species to extinction. However, the old saying, “Follow the river and it will eventually lead you to a sea”, is no longer wholly true. They not only supply the most essential of all natural resources – water – but also sustain biodiversity, which in turn supports human beings. Major river systems are the lifelines of large sections of the world’s population. ![]()
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