Forests : Keeping Our Water Clean

Want Water? Keep FOREST! Clean water is the main basis for human needs for drinking and domestic activities such as washing, bathing, and others. Then, from which we can obtain clean water, especially natural water (taken directly from nature without any treatment)? The answer is simple, that is derived from the springs.Springs originally from? Originally it is from rain catchment areas, namely forest. The existence of this forest is very important for the availability of clean water, so the World Resources Institute proposed forest guard in the provision of clean water for the long term. 

Siput Bisa Monitor Polusi Udara

Snail (Sumber : NGI Online)

Siput, hewan yang lambat, berlendir dan bahkan terkadang menjijikan ini ternyata bisa jadi sangat bermanfaat buat lingkungan. Perusahaan air di St. Petersburg, Rusia, menggunakan enam siput sebesar tikus untuk memonitor emisi yang dihasilkan oleh tempat pembakaran limbah.

Kesehatan siput dipantau. Kondisi siput yang menurun menandai kalau adanya residu berbahaya yang dihasilkan oleh limbah. "Mereka adalah kontrol ketat kami. Sekarang kami memperhatikan siput sepanjang waktu," kata Olga Rublevskaya, direktur perusahaan pembuangan air di Vodokanal.

ACID RAIN AND GROUND WATER PH

An important measure of water quality is its pH. The letters (pH) describe the acidic or basic nature of a substance. Scientifically a liquid’s pH is a measure of the concentration of hydrogen ions (H+ ) it contains. The Danish biochemist S.P.L. Sorenson originally proposed the concept or the pH scale in 1909 as a method to describe the “acidity” of beer.

The pH scale ranges from 0 to 14 with a value of 7 indicating a neutral pH (neither acidic nor basic]. Distilled water has a pH of 7. Basic (or alkaline) solutions (i.e. bleach and ammonia) have values greater than 7. Acidic solutions (i.e. battery acid, lemon juice, and vinegar) have values less than 7. Each unit change in pH is equal to a 10-fold (10 times) change in the pH. The table shows the approximate pH value for some common substances. Rain and snow (the principal sources of ground water) have pH values near 5.6, if they are relatively free of pollution. However, in many areas of the United States “acid rain” is now the norm because of pollution emissions from sources such as coal-fired power plants and car exhaust. Acid rain can have pH value near 4. There are concerns that acid rain is having effects on vegetation and aquatic fauna. Once on the ground, some of the acidic precipitation infiltrates downward to mix with ground water and can affect the ground water pH.

RAIN WATER HARVESTING AND ARTIFICIAL RECHARGE TO GROUND WATER

WHAT IS RAIN WATER HARVESTING ?

The principle of collecting and using precipitation from a catchment surface. An old technology is gaining popularity in a new way. Rain water harvesting is enjoying a renaissance of sorts in the world, but it traces its history to biblical times. Extensive rain water harvesting apparatus existed 4000 years ago in the Palestine and Greece. In ancient Rome, residences were built with individual cisterns and paved courtyards to capture rain water to augment water from city's aqueducts. As early as the third millennium BC, farming communities in Baluchistan impounded rain water and used it for irrigation dames, build of stone rubble, were found in Baluchistan and Kutch in Gujarat in India.

ARTIFICIAL RECHARGE TO GROUND WATER

Artificial recharge to ground water is a process by which the ground water reservoir is augmented at a rate exceeding that obtaining under natural conditions of replenishment. Any man-made scheme or facility that adds water to an aquifer may be considered to be an artificial recharge system.

Water cycle

Water Cycle

The hydrosphere – the surface and near-surface waters of the Earth – is made of meteoric water.The water cycle is the circulation of meteoric water through the hydrosphere, atmosphere, and upper parts of the crust. It is linked to the circulation of deep-seated juvenile water associated with magma production and the rock cycle. Juvenile water ascends from deep rock layers through volcanoes, where it issues into the meteoric zone for the first time. On the other hand, meteoric water held in hydrous minerals and pore spaces in sediments, known as connate water, may be removed from the meteoric cycle at subduction sites, where it is carried deep inside the Earth.

TSUNAMIS : Killer Waves

Tsunami in Sendai, Japan (12/03/11)

A tsunami is a series of ocean waves that sends surges of water, sometimes reaching heights of over 100 feet (30.5 meters), onto land. These walls of water can cause widespread destruction when they crash ashore.

These awe-inspiring waves are typically caused by large, undersea earthquakes at tectonic plate boundaries. When the ocean floor at a plate boundary rises or falls suddenly it displaces the water above it and launches the rolling waves that will become a tsunami.

Most tsunamis, about 80 percent, happen within the Pacific Ocean’s “Ring of Fire,” a geologically active area where tectonic shifts make volcanoes and earthquakes common.

Tsunamis may also be caused by underwater landslides or volcanic eruptions. They may even be launched, as they frequently were in Earth’s ancient past, by the impact of a large meteorite plunging into an ocean.

Epicenter of Japan Earthquake (12/03/11)

Tsunamis race across the sea at up to 500 miles (805 kilometers) an hour—about as fast as a jet airplane. At that pace they can cross the entire expanse of the Pacific Ocean in less than a day. And their long wavelengths mean they lose very little energy along the way.

In deep ocean, tsunami waves may appear only a foot or so high. But as they approach shoreline and enter shallower water they slow down and begin to grow in energy and height. The tops of the waves move faster than their bottoms do, which causes them to rise precipitously.

A tsunami’s trough, the low point beneath the wave’s crest, often reaches shore first. When it does, it produces a vacuum effect that sucks coastal water seaward and exposes harbor and sea floors. This retreating of sea water is an important warning sign of a tsunami, because the wave’s crest and its enormous volume of water typically hit shore five minutes or so later. Recognizing this phenomenon can save lives.

A tsunami is usually composed of a series of waves, called a wave train, so its destructive force may be compounded as successive waves reach shore. People experiencing a tsunami should remember that the danger may not have passed with the first wave and should await official word that it is safe to return to vulnerable locations.

Some tsunamis do not appear on shore as massive breaking waves but instead resemble a quickly surging tide that inundates coastal areas.

The best defense against any tsunami is early warning that allows people to seek higher ground. The Pacific Tsunami Warning System, a coalition of 26 nations headquartered in Hawaii, maintains a web of seismic equipment and water level gauges to identify tsunamis at sea. Similar systems are proposed to protect coastal areas worldwide.

Published By : National Geographic

image by Photograph by Deshakalyan Chowdhury/AFP/Getty Images

STORM TIDES

storm tides

Coastal communities are at risk

Historical settlement patterns have resulted in Australia having most of its major city developments situated on the coastline. Storm tides are a major natural hazard for coastal regions. Severe storms and cyclones contribute 29 per cent of the total damage cost from natural hazards to the Australian community. In 1999 prices, this amounts to $40 billion during the period 1967 to 1999 (including the cost of deaths and injuries).

HUJAN ASAM (ACID RAIN)

Salah satu parameter yang menentukan baik buruknya kualitas air adalah pH. (American Ground Water Trust, 2003). Secara ilmiah, pH sendiri diartikan sebagai banyak sedikitnya kandungan ion H+ dalam suatu benda, baik itu cairan maupun padat. Kadar pH memiliki rentangan dari 0 (asam kuat) sampai 14 (basa kuat) dengan 7 adalah harga tengah mewakili air murni (netral). (www.chem-is-try.org).

Geomorfologi : Bentuklahan Eolin

Kerja angin mempunyai 2 aspek, yaitu erosif dan akumulatif. Akumulatif seperti yang terjadi di daerah pantai berpasir sangat dipengaruhi oleh ukuran butir dari materialnya. Bentuk-bentuk gumuk pasir seperti barchan, parabolik, longitudinal dan transversal merupakan tipe gumuk pasir yang berkembang di bawah pengaruh aktivitas angin. Gumuk pasir merupakan akumulasi pasir lepas berupa gundukan dengan bentuk teratur.

            Umumnya gumuk pasir terbentuk pada pantai berpasir yang landai dan datar, ada angin yang berhembus dengan kecepatan tinggi, sinar matahari kontinyu, ada akumulasi pasir yang berasal dari sungai yang bermuara di situ, terdapat bukit penghalang di belakang pantai dan tumbuhan berupa spinifex lithorus, pandanus, calanthropus gigantae, ipomoa pescaprae dan kaktus.

            Beberapa ciri khusus antara lain berstruktur sedimen permukaan gelembur gelombang (ripple mark) akibat pergeseran butiran pasir pengaruh arah angin, perlapisan horisontal di bagian dalam, lapisan bersusun dan silang siur. Rona cerah, tekstur halus-seragam, pola teratur dan banyak sungai bermuara dan melebar akibat pertemuan dengan laut. Kadang terbentuk danau tapal kuda (“oxbow lake”), sungai berpindah dan akumulasi material pasir di depan tebing penghalang. 

Hurricanes : Engines of Destruction

Hurricanes are giant, spiraling tropical storms that can pack wind speeds of over 160 miles (257 kilometers) an hour and unleash more than 2.4 trillion gallons (9 trillion liters) of rain a day. These same tropical storms are known as cyclones in the northern Indian Ocean and Bay of Bengal, and as typhoons in the western Pacific Ocean.

The Atlantic Ocean’s hurricane season peaks from mid-August to late October and averages five to six hurricanes per year.

Hurricanes begin as tropical disturbances in warm ocean waters with surface temperatures of at least 80 degrees Fahrenheit (26.5 degrees Celsius). These low pressure systems are fed by energy from the warm seas. If a storm achieves wind speeds of 38 miles (61 kilometers) an hour, it becomes known as a tropical depression. A tropical depression becomes a tropical storm, and is given a name, when its sustained wind speeds top 39 miles (63 kilometers) an hour. When a storm’s sustained wind speeds reach 74 miles (119 kilometers) an hour it becomes a hurricane and earns a category rating of 1 to 5 on the Saffir-Simpson scale.

Hurricanes are enormous heat engines that generate energy on a staggering scale. They draw heat from warm, moist ocean air and release it through condensation of water vapor in thunderstorms.

Hurricanes spin around a low-pressure center known as the “eye.” Sinking air makes this 20- to 30-mile-wide (32- to 48-kilometer-wide) area notoriously calm. But the eye is surrounded by a circular “eye wall” that hosts the storm’s strongest winds and rain.

These storms bring destruction ashore in many different ways. When a hurricane makes landfall it often produces a devastating storm surge that can reach 20 feet (6 meters) high and extend nearly 100 miles (161 kilometers). Ninety percent of all hurricane deaths result from storm surges.

A hurricane’s high winds are also destructive and may spawn tornadoes. Torrential rains cause further damage by spawning floods and landslides, which may occur many miles inland.

The best defense against a hurricane is an accurate forecast that gives people time to get out of its way. The National Hurricane Center issues hurricane watches for storms that may endanger communities, and hurricane warnings for storms that will make landfall within 24 hours.

Sources : National Geographic