#Brazil : “Worst Drought Conditions on Record Hit People in over 140 Brazilian Cities”

#AceNewsServices says that over 140 Brazilian cities have been pushed to ration water during the worst drought on record, according to a survey conducted by the country’s leading newspaper. Some neighborhoods only receive water once every three days.

A worker of SABESP looks at the cracked ground of Jaguary dam in Braganca PaulistaWater is being rationed to nearly 6 million people living in a total of 142 cities across 11 states in Brazil, the world’s leading exporter of soy-beans, coffee, orange juice, sugar and beef.

Water supply companies told the Folha de S. Paulo newspaper that the country’s reservoirs, rivers and streams are the driest they have been in 20 years.

A record heat wave could raise energy prices and damage crops. 

Some neighbourhoods in the city of Itu in Sao Paulo state (which accounts for one-quarter of Brazil’s population and one-third of its GDP), only receive water once every three days, for a total of 13 hours.

 

 

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Science of Sink Holes: So Are the Builders Causing the Disaster's to Occur by Building Our Homes and Roads in the Wrong Places?

: Santa Fe River: Sinkhole where the river goe...

: Santa Fe River: Sinkhole where the river goes underground for 3 miles, forming a natural land bridge. (Photo credit: Wikipedia)

Sinkholes are they causing the disaster to occur or are the builder’s by sighting our homes and roads in the wrong places, without due regard to how, what and why they occur?

Learn more about sinkholes.USGS Science Feature


The Science of Sinkholes

Picture of a sinkhole in Florida.Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground. Sinkholes are dramatic because the land usually stays intact for a while until the underground spaces just get too big. If there is not enough support for the land above the spaces then a sudden collapse of the land surface can occur. These collapses can be small, or, as this picture shows, or they can be huge and can occur where a house or road is on top.

The most damage from sinkholes tends to occur in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. The picture to the left shows a sinkhole that quickly opened up in Florida, apparently eating a swimming pool, some roadway, and buildings.

What is a “Sinkhole”?

Picture of a sinkhole that formed below part of a house.A sinkhole is an area of ground that has no natural external surface drainage–when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes can vary from a few feet to hundreds of acres and from less than 1 to more than 100 feet deep. Some are shaped like shallow bowls or saucers whereas others have vertical walls; some hold water and form natural ponds. Typically, sinkholes form so slowly that little change is noticeable, but they can form suddenly when a collapse occurs. Such a collapse can have a dramatic effect if it occurs in an urban setting.

Areas prone to collapse sinkholes

The map below shows areas of the United States where certain rock types that are susceptible to dissolution in water occur. In these areas the formation of underground cavities can form and catastrophic sinkholes can happen. These rock types are evaporites (salt, gypsum, and anhydrite) and carbonates (limestone and dolomite). Evaporite rocks underlie about 35 to 40 percent of the United States, though in many areas they are buried at great depths.

Map of the United States showing areas where rock that are prone to dissolution and sinkholes are prevalent.

Types of sinkholes

Since Florida is prone to sinkholes, it is a good place to use to discuss some different types of sinkholes and the geologic and hydrologic processes that form them. The processes of dissolution, where surface rock that are soluble to weak acids, are dissolved, and suffosion, where cavities form below the land surface, are responsible for virtually all sinkholes in Florida.

Dissolution sinkholes

Diagram of a sinkhole caused by dissolution of subsurface rock, generally limestone. Dissolution of the limestone or dolomite is most intensive where the water first contacts the rock surface. Aggressive dissolution also occurs where flow is focussed in preexisting openings in the rock, such as along joints, fractures, and bedding planes, and in the zone of water-table fluctuation where groundwater is in contact with the atmosphere.

Cover-subsidence sinkholes

Cover-subsidence sinkholes tend to develop gradually where the covering sediments are permeable and contain sand. In areas where cover material is thicker or sediments contain more clay, cover-subsidence sinkholes are relatively uncommon, are smaller, and may go undetected for long periods.

Cover-collapse sinkholes

Cover-collapse sinkholes may develop abruptly (over a period of hours) and cause catastrophic damages. They occur where the covering sediments contain a significant amount of clay. Over time, surface drainage, erosion, and deposition of sinkhole into a shallower bowl-shaped depression.

Diagram showing cover-collapse types of sinkholes.

Sinkholes can be human-induced

New sinkholes have been correlated to land-use practices, especially from groundwater pumping and from construction and development practices. Sinkholes can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created. The substantial weight of the new material can trigger an underground collapse of supporting material, thus causing a sinkhole.

Hydrologic cycle of water from atmosphere to g...

Hydrologic cycle of water from atmosphere to ground in Florida, including the formation of sinkholes, artesian wells, springs, and confluence of salt water from the ocean (Photo credit: Wikipedia)

The overburden sediments that cover buried cavities in the aquifer systems are delicately balanced by ground-water fluid pressure. The water below ground is actually helping to keep the surface soil in place. Groundwater pumping for urban water supply and for irrigation can produce new sinkholes In sinkhole-prone areas. If pumping results in a lowering of groundwater levels, then underground structural failure, and thus, sinkholes, can occur.

Take our groundwater true/false quiz.  Groundwater true/false quiz

Sources and more information

 • Sinkholes, USGS Fact Sheet 2007-3060
• Land Subsidence in the United States, U.S. Geological Survey Circular 1182
• Land Subsidence in the United States, USGS Fact Sheet-165-00
• Carbonate-rock aquifers, Aquifer Basics

http://www.stableliftfoundationrepair.com/

#acesciencenews, #alabama, #environment, #florida, #groundwater, #land-surface, #sinkhole, #terrain, #texas, #united-states, #united-states-geological-survey, #water-resources

Weather Alert Model – That could forecast water leaks more accurately – but who pays?

Met Office shows new water leakage model

17 October 2013 – The Met Office will show its new leakage model along with its other Weather Intelligence Models for demand, seasonal night use, pipe burst and turbidity data – at the UK Water Annual Leakage Conference, 24 October 2013.

Burst water pipe

The Met Office will show its new leakage model along with its other Weather Intelligence Models for demand, seasonal night use, pipe burst and turbidity data – at the UK Water Annual Leakage Conference, 24 October 2013.

Historically water leakage has been difficult for water companies to quantify or forecast accurately across water networks and resource zones, because of the large weather dependency. Understanding this weather dependency enables accurate modelling and reporting of the leakage.

Leakages account for up to 30% of the total annual distribution input across the water company’s network. The Met Office’s leakage prediction model assesses and predicts the influence of weather on leakage, which is known to particularly increase in periods of winter weather. The model allows for the close management of weather related leakage, on a week by week basis, enabling the water company to monitor and review its leakage strategy and expenditure on leakage reduction work can be set against levels of risk.

Thames Water

Thames Water (Photo credit: Wikipedia)

The launch of the new Met Office weather intelligence models follows a successful collaboration with Thames Water to make the suite of models available across the whole water industry. The models, which have been developed to include the Met Office’s world leading weather data, can be adapted and calibrated to individual water company regions.

Michelle Spillar, Head of Utilities at the Met Office, says, “Our new modelling suite enables water companies to perform day by day network monitoring, forecast trends and analyse actual and predicted future events tailored to their specific network characteristics – offering multiple benefits and cost savings across water resources‘ strategy and operations.”

In addition to leakage the Met Office’s suite of weather intelligence models consists of:

Burst model

  • Increases in pipe burst occurrence during cold-weather winter periods cause large fluctuations in workload and resources required in call centre and repair teams.
  • Understanding and modelling weather related pipe bursts enables prediction of likely burst numbers on a 15 day time scale, allows for optimal resource deployment.
  • Integration of the burst model into contingency planning and emergency response, allows some of the worst impacts of winter weather to be modelled and quantified with mitigation activities planned.

Demand model

  • Summer water demand can vary by up to 10% according to the weather.
  • The Met Office’s demand model can be used for long-term strategic and short-term operational demand modelling, prediction and water resource management.
  • The model allows water companies to manage service reservoir storage levels optimally, providing efficiencies in energy use and security of supply during peak periods. Maintenance activities can be scheduled with increased confidence and assessment of the business benefits of implementing demand management measures, such as temporary use bans, can be undertaken accurately.

Seasonal night usage model

  • Night usage of water is known to increase in summer, in accordance with hot and dry weather conditions and other relevant factors.
  • Separating additional summer night use and leakage is challenging for water companies.
  • The seasonal night use model allows seasonal usage increases to be separated from leakage. Leakage trends across different resource zones over the summer can be monitored with the weather signal removed and leakage planners are able to use the seasonal night use model results to target detection resources effectively during the summer. Accurate assessments of true leakage early in the year, can benefit leakage targeting later in the year.

Turbidity model

  • The measurement of turbidity, the cloudiness or haziness of a fluid, is a key test of water quality.
  • Heavy rainfall causes increases in the levels of suspended particles in rivers, increasing the level of treatment needed.
  • The cost incurred in bringing the untreated water up to drinking water quality can increase the cost of production by up to five times.
  • The turbidity model enables the relationship between heavy rainfall and turbidity to be modelled, helping manage resources and minimise the impact of high turbidity events.

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