Archive for the 'erosion' Category

Landslide Risk at Reservoir Cited in China

Published on 04/19/2012 in dam removal, dams, displacement of people, erosion and floods. 0 Comments Tags: , , , .

“A growing threat of landslides on ground surrounding the massive Three Gorges Dam reservoir could force the government to relocate 100,000 more residents of the area, from which 46,000 were moved earlier, an expert with China’s land and resources ministry said this week.

“The dam, the world’s largest hydroelectric project, has been a target of criticism by environmentalists and some geologists since before the reservoir began to inundate a long stretch of the Yangtze River, long regarded as one of the world’s scenic wonders, in 2003. A massive landslide occurred that year, followed by others, but only in 2007 did the government admit that the rising waters were causing instability and that a catastrophe could occur unless preventive steps were taken.

“Officials have recorded 430 landslides and nearly 2,900 smaller geological incidents along the lakeshore, and 5,386 other potentially dangerous sites are being monitored, Mr. Liu said.

“The government relocated 1.4 million people to build the dam and reservoir, which is comparatively narrow but longer than Lake Superior in North America. The latest proposed relocation would affect residents along hundreds of miles of twisting lakeshore from Jiangjin, in the Chongqing municipality, to the dam’s location at Yichang, in Hubei Province.”

Read More: nytimes

Chippie Kislik

Africa’s great ‘water grab’

Published on 12/03/2011 in agriculture, deforestation, desertification, displacement of people, drought, erosion, hydrology, policy, rivers, water rights, water shortage, water wars and world water supply. 0 Comments

The banks of the Niger river, in southern Mali, have been flooded by a steady stream of foreigners. Coveted by foreign investors eager to snap up large tracts of fertile farmland, the river basin has been at the centre of a race to get hold of African land at rock-bottom prices. Meanwhile, last week, hundreds of smallholder farmers and civil society activists flocked to the same river basin for the first international conference to tackle the global rush for land.

West Africa‘s largest river, the Niger is thought to sustain over 100 million people as it snakes 4,180km through Guinea, Mali and Niger before emptying into Nigeria’s colossal Niger Delta. In Mali, the Office du Niger is home to the vast majority of the country’s largescale land deals, seen by campaigners as emblematic of the “land grabs” taking place in developing countries. Recent estimates suggest that foreign investment in Mali’s limited arable land jumped by 60% between 2009 and 2010. But the potential knock-on effects of these land deals on local communities’ access to water has rarely made it centre-stage.

Ongoing research from the London-based International Institute for Environment and Development seeks to redress this blindspot, honing in on how such land deals might affect water access for fishing, farming and pastoralist communities. In a policy paper out on Thursday, the IIED’s Jamie Skinner and Lorenzo Cotula warn that an alarming number of African governments seem to be signing away water rights for decades, with major implications for local communities.

Read More: The Guardian

 

jenna cavelle

Australia’s Breadbasket Faces Water Squeeze

Published on 12/01/2011 in agriculture, drought, erosion, groundwater, management, peak water and water rights. 0 Comments

“CANBERRA—A plan to reduce water use in Australia’s key food-producing region is pitting farmers against environmentalists and throwing the long-term future of the country’s breadbasket into question.

The release of a draft plan to cut the supply of irrigation water in the Murray-Darling Basin, an area about the size of Texas and California combined, has angered both sides. Conservationists say it isn’t enough to restore local river systems and farmers say it could cost thousands of jobs and drive up food prices.

The basin, degraded by drought, state governments’ overallocation of water rights and by rising levels of salinity in the soil, an effect of irrigation, generates about 15 billion Australian dollars (US$14.7 billion) in agricultural produce a year, mostly grains, livestock and fiber. It accounts for 40% of national farm output by value and well over half of irrigated farm production, using nearly all the water held in the basin area.

The new plan, published over the weekend, proposes to recover 2,750 gigaliters of water a year—more than five times the volume found in the Sydney Harbour area—from irrigators in the Murray-Darling Basin. One gigaliter, a billion liters, is enough to fill about 444 Olympic swimming pools.”

Read More: Online Wall Street Journal

 

 

jenna cavelle

Ravi Water Flow: India, Pak Engineers Battle It Out

Published on 07/01/2011 in erosion, floods, rivers, water diversions and water wars. 0 Comments Tags: , .

Ravi River. Retrieved from: www.skyscrapercity.com

“AMRITSAR: Every year the banks of river Ravi becomes the battle field for the engineers of both India and Pakistan during rainy the season. Indian engineers are at war of wits with their Pakistani counterparts in not only preventing the erosion of strategically important land on banks of Ravi but also in neutralising Pakistan’s offensive to deflect river course to India.

Sources informed TOI on Thursday that Pakistan has constructed various bundhs along the river in Amritsar and Gurdaspur sectors to deflect the river course. They have also constructed defense structures including bunkers by raising high bundh on Ichhogil canal.

Due to construction of these bundhs, a large part of land from Ranian and Kakkar villages of Indian side are washed away during the rainy season. During this season Pakistan releases water, nearly one lakh cusec, from its villages of Mandhal and Marala and it increases the water level in Indian villages up to 3 lakh cusec. This high flow of water submerges villages around Ranian and Kakkar. ”

Read more: The Times of India

lily victoria

Estuaries on the northwestern coast of Madagascar As Seen From Orbit

Published on 06/23/2011 in aquatic ecosystems, erosion, riparian zone and rivers. 0 Comments Tags: , , , , , .

Estuaries on the northwestern coast of Madagascar are featured in this image photographed by an Expedition 28 crew member on the International Space Station. Photo retrieved from: www.spaceref.com

“This photograph highlights two estuaries located along the northwestern coastline of the island of Madagascar. The Mozambique Channel (top) separates Madagascar from the southeastern coast of Africa. Bombetoka Bay (upper left) is fed by the Betsiboka River and is a frequent subject of astronaut photography due to its striking red floodplain sediments. Mahajamba Bay (right) is fed by several rivers including the Mahajamba and Sofia Rivers; like the Betsiboka, the floodplains of these rivers also contain reddish sediments eroded from their basins upstream.

The brackish (mix of fresh and salty water) conditions found in most estuaries host unique plant and animal species adapted to live in such environments. Mangroves in particular are a common plant species found in and around Madagascar estuaries, and Bombetoka Bay contains some of the largest remaining stands. Estuaries also host abundant fish and shellfish species — many of which need access to freshwater for a portion of their life cycles — and these in turn support local and migratory bird species that prey on them.

However, human activities such as urban development, overfishing, and increased sediment loading from erosion of upriver highlands threaten the ecosystem health of the estuaries. In particular, the silt deposits in Bombetoka Bay at the mouth of the Betsiboka River have been filling in the bay.”

Read more: Spaceref

lily victoria

China admits problems with Three Gorges Dam

Published on 05/25/2011 in aquatic ecosystems, dams, drought, erosion, floods, groundwater, hydrology, hydropower, management, peak water, rivers, species extinction and world water supply. 0 Comments Tags: , , , , , .

dam skippy

Photo retrieved from: NatureNews.com

“China has finally admitted that all is not rosy with its Three Gorges Dam, the world’s largest hydroelectric power project. The dam is plagued by problems that need to be resolved urgently, the State Council — China’s cabinet — said last Wednesday.

“The statement was made after a high-level meeting presided over by Premier Wen Jiabao, and highlights issues such as pollution, silt accumulation, ecological deterioration and geological hazards near the dam. It also points out the project’s adverse effects on irrigation, water supply and shipping in downstream regions, which affect an area of 633,000 square kilometres over eight provinces. These problems should be addressed through more research and monitoring, and more efficient dam operation, the statement says.

“The admission was welcomed by Ma Jun, director of the Institute of Public and Environment Affairs, a non-governmental organization in Beijing. “Although China had acknowledged problems in the dam areas before, this was the first time that it admitted the project’s negative impact on the middle and lower reaches of the river,” he says.”

read more: Nature News

chrismorrow

Smithsonian Studies Landslides: How Rainfall Dried Up Panama’s Drinking Water

Published on 05/16/2011 in contaminated water, erosion and floods. 0 Comments Tags: , , , , , , , .

Retrieved from: art daily

“To understand the long-term effects of a prolonged tropical storm in the Panama Canal watershed, Robert Stallard, staff scientist at the Smithsonian Tropical Research Institute and research hydrologist at the U.S. Geological Survey, and Armando Ubeda, the LightHawk Mesoamerica program manager, organized four flights over the watershed to create a digital map of landslide scars.

“Two feet of heavy rain inundated the Panama Canal watershed between Dec. 7 and 10, 2010. Landslides tore down steep slopes, choking rivers with sediment and overwhelming Panama City’s water-treatment plant. Flooding closed the Panama Canal for the first time since 1935. Despite the deluge, the influx of sediments in the water forced authorities to shut down the plant, leaving a million residents of central Panama without clean drinking water for nearly a month.

“LightHawk, a conservation organization based in the U.S., donates flights for research and conservation efforts. Retired United Airlines captain David Cole flew the Cessna 206 aircraft, and the four flights yielded images of 191 square miles (495 square kilometers) of watershed. Stallard observed numerous new landslide scars left behind by the December storm, supporting his prediction that landslides supplied much of the suspended sediment that disrupted Panama’s water supply.

“The new watershed erosion map will allow Stallard and collaborators from the Panama Canal Authority to calculate the landslide risk of future storms and direct strategies to minimize the effect on Panama’s water supply.

“Tropical hydrologists agree that river-borne sediment originates from surface erosion or from deep erosion from landslides. In 1985, Stallard predicted that “deep erosion, not shallow surface erosion, is the primary process controlling the chemistry and sediment levels in many tropical rivers that pass through mountainous areas.” Few studies have been conducted to test this prediction.

“Deforestation of steep slopes is the primary factor determining the number of landslides. Six decades of aerial photographs analyzed by USGS researchers in similar landscapes in Puerto Rico showed that landslide frequency doubles outside protected nature preserves, and that roads and infrastructure make landslides eight times more likely. Although landslides happen in natural forests, the objective is to limit their impact through appropriate land-use practices.”

Read more: art daily

sammykayed

Drought Descends On Texas, Surrounding States

Published on 05/09/2011 in agriculture, climate change, drought, erosion, floods and water shortage. 0 Comments Tags: , , , .

Photo retrieved from: www.seacoastonline.com

“Much of Texas is bone dry, with scarcely any moisture to be found in the top layers of soil. Grass is so dry it crunches underfoot in many places. The nation’s leading cattle-producing state just endured its driest seven-month span on record, and some ranchers are culling their herds to avoid paying supplemental feed costs.

May is typically the wettest month in Texas, and farmers planting on non-irrigated acres are clinging to hope that relief arrives in the next few weeks.

“It doesn’t look bright right at the moment, but I haven’t given up yet,” said cotton producer Rickey Bearden, who grows about two-thirds of his 9,000 acres without irrigation in West Texas. “We’ll have to have some help from Mother’s Nature.”

That the drought is looming over the Southwest while floodwaters rise in the Midwest and South reflects a classic signature of the La Nina weather oscillation, a cooling of the central Pacific Ocean.

This year’s La Nina is the sixth-strongest in records dating back to 1949.

“It’s a shift of the jet stream, providing all that moisture and shifting it away from the south, so you’ve seen a lot of drought in Texas,” Mike Halpert, deputy director of the federal government’s Climate Prediction Center in Silver Spring, Md.”

Read more: Associated Press

 

lily victoria

USGS: Manmade flood leads to rise in rainbow trout

Published on 02/10/2011 in dams, erosion, floods, riparian zone, rivers and water diversions. 0 Comments Tags: , , , , , , , , .

Retrieved from: USGS

“The flood of water from Glen Canyon Dam in 2008 was meant to build up sandbars for camping sites, protect archaeological resources and provide critical habitat for plants and animals, including the endangered humpback chub.

“The unanticipated consequence was that the flood cleared the gravel floor just below the dam where rainbow trout lay their nests. As the fish grew, they found themselves competing for limited food and some moved downstream to fight for the same resources as the humpback chub at the confluence of the Little Colorado and Colorado rivers, said Ted Melis, deputy chief of the U.S. Geological Survey’s Grand Canyon Research and Monitoring Center in Flagstaff.

“The rainbow trout that had been declining in numbers since 2001 in the Colorado River rose by 800 percent between 2007 and 2009, he said. The increase followed efforts to remove more than 23,000 rainbow trout from areas where humpback chub thrive.

“The latest flood sent enough water through the Colorado River to fill 108,000 Olympic-sized swimming pools, filling one pool every two seconds over 60 hours.

“Two-thirds of artificial floods would occur in the fall if they were timed to follow the natural deposits of those tributaries, but Melis said that strategy doesn’t ensure success.

“Research has shown that the floods increase the volume of sandbars in the Grand Canyon but less is known about how they impact the animal and plant life in the river.

“Since the 1960s, Glen Canyon Dam has blocked 90 percent of sediment from the Colorado from flowing downstream, turning the once muddy and warm river into a cool, clear environment that helped speed the spread of extinction of fish species and pushed others near the edge.”

Read more: Necn

sammykayed

Amazon Drought May Have Bigger Impact On Global Warming Than U.S. Does In A Year

Published on 02/07/2011 in climate change, deforestation, desertification, drought, erosion, rivers and water shortage. 0 Comments Tags: , , .

Photo retrieved from: www.huffingtonpost.com

“A widespread drought in the Amazon rain forest last year was worse than the “once-in-a-century” dry spell in 2005 and may have a bigger impact on global warming than the United States does in a year, British and Brazilian scientists said on Thursday.

More frequent severe droughts like those in 2005 and 2010 risk turning the world’s largest rain forest from a sponge that absorbs carbon emissions into a source of the gases, accelerating global warming, the report found.

Trees and other vegetation in the world’s forests soak up heat-trapping carbon dioxide as they grow, helping cool the planet, but release it when they die and rot.

“If events like this happen more often, the Amazon rain forest would reach a point where it shifts from being a valuable carbon sink slowing climate change to a major source of greenhouse gases that could speed it up,” said lead author Simon Lewis, an ecologist at the University of Leeds.

The study, published in the journal Science, found that last year’s drought caused rainfall shortages over a 1.16 million square-mile (3 million square km) expanse of the forest, compared with 734,000 square miles (1.9 million square km) in the 2005 drought.

It was also more intense, causing higher tree mortality and having three major epicenters, whereas the 2005 drought was mainly focused in the southwestern Amazon.”

Read more: Huffington Post

lily victoria