Related Posts Plugin for WordPress, Blogger...

PAGES

Tuesday, December 15, 2009

Water Crisis - We Are Running Out of Water

It is worrisome that we would be talking of water crisis, scarcity or problems when two-third of our world is composed of water. Of the whole bulk of water on earth, only 2.5 per cent is fresh and suitable for human and agricultural use. This makes usable water a finite resource. Of this 2.5 percent, 99 per cent is held up in icebergs, glaciers or underground. Only 1 per cent of freshwater is therefore available to the nearly 7 billion human population and a countless other forms of life.

This tiny fraction of freshwater is unevenly distributed throughout the world. So, some people have much, while others have almost none. In some countries like Nigeria and Mali, quantity is not a problem, but distribution and quality are. This is commonly so in developing nations.

Each year, about 3.575 million people die from water-related disease. Million of people die globally from poor sanitation and contaminated water. Ninety per cent of the victims are children. Over a third of the world's population is seriously affected by water and sanitation crisis.

While the world's population tripled in the 20th century, the use of renewable water resources has grown six-fold. Within the next fifty years, the world population will increase by another 40 to 50 %. This population growth, coupled with industrialization and urbanization, will result in an increasing demand for water and will have serious consequences on the environment. Thus, the water crisis would continue to heighten.

People Lacking Water

More than one out of six people lack access to safe drinking water, namely 1.1 billion people, and more than two out of six lack adequate sanitation, namely 2.6 billion people 3900 children die every day from water borne diseases. One must know that these figures represent only people with very poor conditions. In reality, these figures should be much higher.

As the resource is becoming scarce, tensions among different users may intensify, both at the national and international level. Over 260 river basins are shared by two or more countries. In the absence of strong institutions and agreements, changes within a basin can lead to trans-boundary tensions. When major projects proceed without regional collaboration, they can become a point of conflicts, heightening regional instability. The Parana La Plata, the Aral Sea, the Jordan and the Danube may serve as examples. Due to the pressure on the Aral Sea, a good proportion of the water has disappeared

Towards A Way to Improve the Situation

The water crisis witness today is not about having too little water to satisfy our needs but rather a crisis of bad management of water.

With the current state of affairs, corrective measures still can be taken to check the worsening situation. There is an increasing awareness that our freshwater resources are limited and need to be protected both in terms of quantity and quality. This water challenge affects not only the water community, but also decision-makers and every human being.

Whatever the use of freshwater (agriculture, industry, domestic use), huge saving of water and improving of water management is possible. Almost everywhere, water is wasted, and as long as people are not facing water scarcity, they believe access to water is an obvious and natural thing. With urbanization and changes in lifestyle and attitude, water consumption is bound to increase. However, changes in food habits, for example, may reduce the problem, knowing that growing 1kg of potatoes requires only 100 litres of water, whereas 1kg of beef requires 13 000 litres.

Trans-boundary Cooperation

As far as trans-boundary conflicts are concerned, regional economic development and cultural preservation can all be strengthened by states cooperating on water-related issues. Instead of a trend towards war, water management can be viewed as a trend towards cooperation and peace. Many initiatives are launched to avoid crises. Institutional commitments like in the Senegal River are created.

Water Crisis Facts
43% of water-related deaths are due to diarrhea.
84% of water-related deaths are in children ages 0 - 14.
98% of water-related deaths occur in the developing world.
884 million people, lack access to safe water supplies, approximately one in eight people.


The water and sanitation crisis claims more lives through disease than any war claims through guns.


At any given time, half of the world's hospital beds are occupied by patients suffering from a water-related disease.

Article Source: http://EzineArticles.com/?expert=Fortune_Ihunweze

Grab Samplers for slow moving river or streams

There are 3 types of grab samplers available

EakmanBottom Grab Samplers

The Ekman Bottom Grab sampler is designed for sampling in soft bottomed lakes and rivers composed of muck, mud or fine peat. As the sampler is lowered, two hinged upper lids swing open to let water pass through and close upon retrieval preventing sample washout. When the sampler reaches the bottom, a messenger is sent down the line tripping the overlapping spring-loaded scoops. Each sampler is constructed of 316 stainless steel including the springs, cables and fasteners. Also available is a 5 ft. and 10 ft. extension handle for operating the sampler in shallow water instead of a cable and messenger. The sampler is also available as a kit which includes stainless 300 gm messenger, 100 ft. cable and carrying case (ordered separately).





Ponar type grab samplers


The Ponar Type Grab sampler is a commonly used sampler that is very versatile for all types of hard bottoms such as sand, gravel and clay. It can be used in streams, lakes reservoirs and the ocean. This modified Van Veen type self-tripping sampler features center hinged jaws and a spring loaded pin that releases when the sampler makes impact with the bottom. It also includes an underlip attachment that cleans gravel from the jaws that would normally prevent lateral loss of sample. The top is covered with a stainless steel screen with neoprene rubber flaps which allows water to flow through for a controlled descent and less interference with the sample. It is constructed of stainless steel with zinc plated steel arms and weights. A simple pin prevents premature closing.

The Ponar style sampler comes in several sizes with the lightweight model (1/8" stainless plate) easily used from a small boat with nylon cable. The heavyweight models (1/4" stainless plate) should be used with a sounding reel.



Van Veen Grab Sampler

The Van Veen grab is a lightweight sampler designed to take large samples in soft bottoms. Its long lever arms and the sharp cutting edges on the bottom of the scoops, enable it to cut deeply into the softer bottoms. The Van Veen grab sampler is manufactured in two sizes from stainless steel. The weighted jaws, chain suspension, and doors and screens allow flow-through during lowering to the bottom and assure vertical descent where strong underwater currents exist. The relatively large surface area and the strong closing mechanism allow the jaws to excavate relatively undisturbed sediments. When the powering cable is slowly made taut, the chains attached at the top of the release exert great tension on the long arms extending beyond the jaws, causing them to lift, dip deeper into the sediment, and trap material as they tightly close. The stainless-steel, 583 micron, door screens have flexible rubber flaps which, during lowering, are lifted. When the grab settles on the bottom, the flaps fall back and cover the screens completely, preventing any loss of sediment during retrieval.




Thursday, December 10, 2009

PCB in Fluoroscent Light

PCBs (Polychlorinated biphenyls) is commonly used as dielectric fluids in electrical equipment such as transformers and capacitors and can be found in metal-cased capacitors in fluorescent lights and it used worldwide.

Generally, short term exposure to PCB such as accidental spills or release of vapours due to overheating of the leaking capacitor does not lead to any long term health effects. however the accessive amounts of PCBs can cause irritation to the eyes and long term health problem with skin, hair and liver.

PCBs are listed as a human carninogen i.e; repeated exposure over a period of years may lead to cancer.