Deforestation cause of flood
They did this even before the flooding, to protect the center. Deforestation: What are some of the effects of deforestation on the environment?. Deforestation plays many roles in the flooding equation because trees prevent sediment runoffs and forests hold more water than farms or grasslands. The flood . Deforestation plays many roles in the flooding equation because trees prevent sediment runoffs and forests hold more water than farms or.
The loss of trees played a major role in the huge Yangtze flood ofsays Janet Abramovitz of Worldwatch, who observes that the Yangtze watershed had lost 85 percent of its forest cover in the past few decades.
Although two other causes of trouble that we'll examine shortly were also at play -- loss of wetlands and river engineering -- Abramovitz says the Chinese government "was trying to blame it all on heavy rains, maybe El Nino or global warming. In terms of flooding, the unimpeded raindrop impact on bare ground leads to heavy erosion and quick runoff. According to Susan Bolton of the University of Washington, the impact comes worst immediately after logging: For the first three or four years, she says, runoff and erosion are greatly increased.
Why do urbanisation and deforestation make flooding more likely? | Earth Observatory of Singapore
Bolton says research in small watersheds shows that after logging, "you might get twice the peak flow, but only for a few years. In real forestry, you grow the trees back," she adds, so that after 30 or 40 years, runoff amounts fall to forested levels.
In larger watersheds, at least in the Pacific Northwest, logging tends to have less impact on peak flows, because only a small portion has been recently clear-cut, she adds.
Deforestation has a second impact on flooding -- the release of sediment.
Vast amounts of eroded soil wind up in river beds, shrinking channels and the river's ability to carry water without flooding. Roads cause soil compaction, and the culverts that funnel water beneath them focus the runoff in gullies. As a result, she says, there's "an increasing emphasis on roads in forestry right now. Some roads are now sloped so water spills directly onto the slope, Bolton says, reducing the gullying and improving infiltration into the soil.
New roads are one thing.
Fewer trees = more floods?
But there are literally millions of miles of roads in U. Forest Service does have a program to remove some, Bolton admits "It's not like you can just erase 50 years of history just like that. The result is faster, higher floods downstream.
Even more problematic than roads, says Bolton, is suburban development, which is "permanent and very pavement-oriented. When deforestation takes place, the top layer of soil can be dislodged — this is also known as soil erosion. When the top layer of soil is unstable, it is unable to retain any of the water that falls on it, resulting in increased surface run-off, which, in turn, increases the risk of flooding. Global warming Deforestation has also increased the risk of flooding indirectly.
When trees are removed from the planet, so too, is their capacity to take in carbon dioxide. Increasing temperatures have facilitated the melting of the polar ice cap that, in turn, causes rising sea levels.Flooding in Argentina blamed on deforestation
The higher sea levels are, the greater the risk of river banks overflowing, and flooding. If you think your own home is at risk of flooding, a waste water pump possesses the capacity to remove any floodwater that does get into your home.
Why deforestation is making flooding more common
In summary then, it is understandable to associate deforestation with flooding. In the absence of trees, interception of rainfall, as well as uptake of groundwater, is dramatically reduced. Alongside the more obvious parallels between deforestation and flooding, are the more indirect effects also.
Deforestation is a very real contributor to global warming — and, by proxy, it is a contributor to rising water levels and increased flooding.