Archive for the 'erosion' Category

Moving Mountains

“When it comes to mining for copper and gold, prospectors will move mountains to make it happen. As in, physically dig up the rock, extract the precious metals and move the debris elsewhere.

In the chilly high altitudes of the Andes Mountains, however, what may look like part of a mountain can in fact be a huge, frozen block of rock fragments and ice. When some of that ice melts in the spring, these so-called “rock glaciers” become a valuable source of water for local populations.

Rock Glacier in the Argentinian Andes, retrieved from UDaily

A scientific team including researchers from the University of Delaware trekked to the Andes in Argentina this month to learn more about rock glacier dynamics. They are estimating how much ice is locked inside rock glaciers where several new mines are being developed and how far the formations move each year.

The effort will aid the mining industry and government officials in determining the potential environmental impacts of disrupting the geological features.

“Mining companies are very concerned about altering or damaging any natural icy landscapes because there is so little water coming out of the high, dry Andes,” said Michael O’Neal, associate professor of geological sciences in UD’s College of Earth, Ocean, and Environment.

O’Neal and two graduate students, Renato Kane and Erika Schreiber, spent two weeks collecting field data in the San Juan Province, situated just east of the Chilean border at altitudes between 10,000 and 15,000 feet. Kane’s thesis work will evaluate year-to-year movements of rock glaciers, which measure roughly one-third of a square mile, using a terrestrial laser scanner.

Rock glaciers form gradually as mountains erode and pieces of rock crumble downwards. Snow blankets the rocks and then melts when temperatures rise, causing water to seep in between crevices before refreezing. Like regular glaciers, rock glaciers move slowly under their own weight and seasonal melt. The scientists will compare data from year to year to track that movement.

“If they truly are active and flowing, we’ll see it when we measure their position,” O’Neal said.

If not, the rock glaciers may be inactive relics of a glacial advance thousands of years ago and no longer contribute to annual water flow.”

Read more: University of Delaware’s UDaily

 

Nile Delta Disappearing Beneath the Sea

Photo retrieved from: www.ipsnews.net

“It only takes a light covering of seawater to render land infertile, so Mohamed Saeed keeps a close watch on the sea as it advances year after year towards his two-hectare plot of land. The young farmer, whose clover field lies just 400 metres from Egypt’s northern coast, reckons he has less than a decade before his field – and livelihood – submerges beneath the sea.

But even before that, his crops will wither and die as seawater infiltrates the local aquifer. The process has already begun, he says, clutching a handful of white-caked soil.

“The land has become sick,” says Saeed. “The soil is saline, the irrigation water is saline, and we have to use a lot of fertilisers to grow anything on it.”

Spread over 25,000 kilometres, the densely populated Nile Delta is the breadbasket of Egypt, accounting for two-thirds of the country’s agricultural production and home to 40 million people. Its northern flank, running 240 kilometres from Alexandria to Port Said, is one of the most vulnerable coastlines in the world, facing the triple threat of coastal erosion, saltwater infiltration, and rising sea levels.

According to Khaled Ouda, a geologist at Assiut University, a 30 centimetres rise in sea level would inundate 6,000 square kilometres of the Nile Delta. The flooding would create islands out of an additional 2,000 square kilometres of elevated land, isolating towns, roads, fields, and industrial facilities.”

Read more: IPS News

 

The Struggle Over Riverbed Mining in India

Photo retrieved from: www.internationalrivers.org

“One specific use of  rivers landmasses has increased manifold in India over the last few decades. Mining of sand, gravel, stones and boulders from riverbeds and riverbanks across the country has seen an unprecedented rise. Each day truckloads of sand and gravel are extracted for a variety of reasons. One of the most important factors driving up demand in recent years has been the growth of the real estate and construction industries. Sand is an important ingredient in concrete, which is the mainstay of the construction industry in India today. Without concrete, high rise apartments, big dams, renovation of city buildings, and multi-utility projects would not see light of the day.

Just as large dams affect entire riverine ecosystems and the people who depend on them, the unregulated and large-scale mining of sand, gravel and stones from riverbeds and riverbanks is not devoid of environmental and social impacts. Riverbed mining causes erosion and often leaves the river-plains much more vulnerable to flooding because it allows loose landmass to be washed downstream, especially during monsoons. This type of mining can also cause salinity intrusion into the rivers, damaging riverine ecosystems. According to the Geological Survey of India (GSI), riverbed mining causes several alterations to the physical characteristics of both a river and riverbed. These can severely impact the ecological equilibrium of a river and damage plants, animals and riparian habitats.”

Read more: International Rivers

 

Suffocating The Desert: L.A.’s Need for Water Hurts Others

Photo retrieved from: www.kcet.org

“The skin of the desert has been peeled away. It is aloft, and it chokes those of us who breathe here. Each scrape from each stray plow or dozer, each square foot of exposed lakebed with the water siphoned off, each section of desert deemed to be more useful as a blank square mile ends up as dust in the air. It hangs in our skies. It collects in our lungs. It kills us by increment, and someone else benefits.

My life has been shortened by living here. I have been sick. For the past eight months I have mostly woken in coughing fits. My abdominal muscles ache from it. My body heals itself as best it can, but the slightest cold, the slightest cloud of vapor from a gas pump that would cause a short moment of choking before I moved here, and I’m off again for weeks. It doesn’t take much dust. One day in a month, perhaps, of the blue sky replaced by khaki and that sick metallic, greasy smell is all it takes.

You might come visit for a weekend at a time and never see the dust. You might never get the feeling in running your fingers through your hair that they come away coated in talcum and static electricity. You might never find yourself wondering if that trip to the grocery store might cost you a day’s work in lung spasms.

Stay here for more than a couple weeks and you will know the feeling.

Dust was in court last week, or at least dust’s advocates at the Los Angeles Department of Water and Power (LADWP) were in court, hearing their lawsuit against the Great Basin Unified Air Pollution Control District get thrown out on a technicality. LADWP is concerned that taking action to keep alkaline dust from blowing off the Owens Lake bed, which it dried out by stages over the last century, would be — in words LADWP uses over and over again — ” “a waste of water.”

Read more: KCET

 

A 12 Step Program to Stopping Drought and Desertification

Photo retrieved from: www.greenprophet.com

“Soaring temperatures and low precipitation could not occur at a worse time for many farmers in the United States, and around the world. Intensifying drought conditions are affecting corn and soybean crops throughout the Midwest, raising grain prices as well as concerns about future food prices.

The US Drought Monitor reports that 88 percent of this year’s corn crop and 77 percent of the soybean crop are now affected by the most severe drought since 1988. In response the Worldwatch Institutelaunched a 12 step guide to combatting drought and desertification. These tips can be used by policy makers around the world and in dry climates in the Middle East. Read on for the list.

1. Agroforestry: Planting trees in and around farms reduces soil erosion by providing a natural barrier against strong winds and rainfall. Tree roots also stabilize and nourish soils. The 1990 Farm Bill established the USDA National Agroforestry Center with the expressed aim of encouraging farmers to grow trees as windbreaks or as part of combined forage and livestock production, among other uses. See Green Prophet’s feature on the Nabateans to see how this idea can be applied in the Middle East.

2. Soil management: Alternating crop species allows soil periods of rest, restores nutrients, and also controls pests. Soil amendments, such as biochar, help soils retain moisture near the surface by providing a direct source of water and nutrients to plant roots, even in times of drought.”

Read more: Green Prophet

 

Waldo Canyon Fire: 20 Percent Of Soil So Severely Burned It Is Likened To ‘Moonscape’

Photo retrieved from: www.huffingtonpost.com

“The Waldo Canyon Fire, the most destructive wildfire in state history, burned so hot that wildfire experts say that nearly 20 percent of the total 18,247 acres (29 square miles) consumed by the blaze was burned so severely that no living vegetation was left on the surface nor root systems left below the surface to a depth of about 4 inches, The Associated Press reports.

The Burned Area Emergency Response (BAER) assessment team determined that 3,375 acres or about 5 square miles was determined to be damaged so badly, left so baren after the blaze ripped through the area that it was likened to moonscape, U.S. Forest Service hydrologist Dana Butler said.

BAER broke the burn severity of the soils and watersheds into three levels, besides the nearly 20 percent severely burned, the group found the remainder of the area to be 41 percent low or unburned severity (7,586 acres) and 40 percent moderate severity (7,286 acres), according to InciWeb.org

Read more: Huffington Post

Africa’s great ‘water grab’

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

 

Australia’s Breadbasket Faces Water Squeeze

“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

 

 

Ravi Water Flow: India, Pak Engineers Battle It Out

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

Estuaries on the northwestern coast of Madagascar As Seen From Orbit

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