Wednesday, December 31, 2008

Remote Sensing-Electromagnetic Spectrum: Distribution of Radiant Energies

Electromagnetic radiation (EMR) extends over a wide range of energies and wavelengths (frequencies). A narrow range of EMR extending from 0.4 to 0.7 µm, the interval detected by the human eye, is known as the visible region (also referred to as light but physicists often use that term to include radiation beyond the visible). White light contains a mix of all wavelengths in the visible region. It was Sir Isaac Newton who first in 1666 carried out an experiment that showed visible light to be a continuous sequence of wavelengths that represented the different color the eye can see. He passed white light through a glass prism and got this result:
Use of a prism to disperse visible light into its spectral colors.

The principle supporting this result is that as radiation passes from one medium to another, it is bent according to a number called the index of refraction. This index is dependent on wavelength, so that the angle of bending varies systematically from red (longer wavelength; lower frequency) to blue (shorter wavelength; higher frequency). The process of separating the constituent colors in white light is known as dispersion. These phenomena also apply to radiation of wavelengths outside the visible (e.g., a crystal's atomic lattice serves as a diffraction device that bends x-rays in different directions).

The distribution of the continuum of all radiant energies can be plotted either as a function of wavelength or of frequency in a chart known as the electromagnetic (EM) spectrum. Using spectroscopes and other radiation detection instruments, over the years scientists have arbitrarily divided the EM spectrum into regions or intervals and applied descriptive names to them.The EM spectrum, plotted here in terms of wavelengths, is shown here.

The EM Spectrum, with specific wavelength intervals assigned Type terms.

Beneath is a composite illustration taken from the Landsat Tutorial Workbook (credited there to Lintz and Simonett, Remote Sensing of the Environment, who identify it as a modification of an earlier diagram by Robt. Colwell) that shows in its upper diagram the named spectral regions in terms of wavelength and frequency and in the lower diagram the physical phenomena that give rise to these radiation types and the instruments (sensors) used to detect the radiation. (Although the width of this second diagram scales closely to the width of the spectrum chart above it, the writer experienced difficulty in centering this second diagram on the present page; it needs some leftward offset so that the narrow pair of vertical lines coincides with the visible range in the upper diagram.)

Wavelength and Frequency representations of the Electromagnetic Spectrum.
Mechanisms (Phenomenology) of generation of EM radiation within wavelength intervals; instruments commonly used in detection of radiation within different intervals.

Although it is somewhat redundant, we reproduce here still another plot of the EM Spectrum, with added items that are self-explanatory:

The EM Spectrum, in a diagram produced by Electro Optical Industries, Inc.

Colors in visible light are familiar to most, but the wavelength limits for each major color are probably not known to most readers. Here is a diagram that specifies these limits (the purple on the far left is in the non-visible ultraviolet; the deep red on the far right is the beginning of the infrared). The human eye is said to be able to distinguish thousands of slightly different colors (one estimate placed this at distinguishable 20000 color tints).

The visible spectrum, with specified (somewhat arbitrary) wavelength boundaries for each color shown.

Different names for (wave)length units within intervals (those specified by types) that subdivide the EM spectrum, and based on the metric system, have been adopted by physicists as shown in this table:

Metric units commonly associated with specific Types of EM Radiation.

(Both in this Tutorial and in other texts, just which units are chosen can be somewhat arbitrary, i.e., the authors may elect to use micrometers or nanometers for a spectral location in the visible. Thus, as an example, 5000 Angstroms, 500 nanometers, and 0.5 micrometers all refer to the same specific wavelength; see next paragraph.)

At the very energetic (high frequency and short wavelength) end are gamma rays and x-rays (whose wavelengths are normally measured in angstroms [Å], which in the metric scale are in units of 10-8 cm). Radiation in the ultraviolet extends from about 300 Å to about 4000 Å. It is convenient to measure the mid-regions of the spectrum in one of two units: micrometers (µm), which are multiples of 10-6 m or nanometers (nm), based on 10-9 m. The visible region occupies the range between 0.4 and 0.7 µm, or its equivalents of 4000 to 7000 Å or 400 to 700 NM The infrared region, spanning between 0.7 and 1000 µm (or 1 mm), has four subintervals of special interest: (1) reflected IR (0.7 - 3.0 µm), and (2) its film responsive subset, the photographic IR (0.7 - 0.9 µm); (3) and (4) thermal bands at (3 - 5 µm) and (8 - 14 µm). We measure longer wavelength intervals in units ranging from mm to cm. to meters. The microwave region spreads across 0.1 to 100 cm, which includes all of the interval used by radar systems. These systems generate their own active radiation and direct it towards targets of interest. The lowest frequency-longest wavelength region beyond 100 cm is the realm of radio bands, from VHF (very high frequency) to ELF (extremely low frequency); units applied to this region is often stated as frequencies in units of Hertz (1 Hz = 1 cycle per second; KHz, MHz and GHz are kilo-, mega-, and giga- Hertz respectively). Within any region, a collection of continuous wavelengths can be partioned into discrete intervals called bands.


Monday, December 29, 2008

Opinion Poll: Terror & Geospatial


Remote Sensing-Electromagnetic Spectrum:Transmittance, Absorptance, and Reflectance

Any beam of photons from some source passing through medium 1 (usually air) that impinges upon an object or target (medium 2) will experience one or more reactions that are summarized in this diagram:

Some objects are capable of transmitting the light through their bulk without significant diminution (note how the beam bends twice at the medium 1/medium 2 interface but emerges at the same angle as entry). Other materials cause the light energy to be absorbed (and in part emitted as longer wavelength radiation). Or, the light can be reflected at the same angle as it formed on approach. Commonly the nature of the object's surface (owing to microscopic roughness) causes it to be scattered in all directions.

The primary source of energy that illuminates natural targets is the Sun. Solar irradiation (also called insolation) arrives at Earth at wavelengths which are determined by the photospheric temperature of the sun (peaking near 5600 °C). The main wavelength interval is between 200 and 3400 nm (0.2 and 3.4 µm), with the maximum power input close to 480 nm (0.48 µm), which is in the visible green region. As solar rays arrive at the Earth, the atmosphere absorbs or backscatters a fraction of them and transmits the remainder.

Upon striking the land and ocean surface (and objects thereon), and atmospheric targets, such as air, moisture, and clouds, the incoming radiation (irradiance) partitions into three modes of energy-interaction response: 

(1) Transmittance (τ) - some fraction (up to 100%) of the radiation penetrates into certain surface materials such as water and if the material is transparent and thin in one dimension, normally passes through, generally with some diminution. 

(2) Absorptance (α) - some radiation is absorbed through electron or molecular reactions within the medium ; a portion of this energy is then re-emitted, usually at longer wavelengths, and some of it remains and heats the target; 

(3) Reflectance (ρ) - some radiation (commonly 100%) reflects (moves away from the target) at specific angles and/or scatters away from the target at various angles, depending on the surface roughness and the angle of incidence of the rays. 

Because they involve ratios (to irradiance), these three parameters are dimensionless numbers (between 0 and 1), but are commonly expressed as percentages. Following the Law of Conservation of Energy: τ + α + ρ = 1. 

A fourth situation, when the emitted radiation results from internal atomic/molecular excitation, usually related to the heat state of a body, is a thermal process. The theory underlying thermal remote sensing is treated in Section 9.

When a remote sensing instrument has a line-of-sight with an object that is reflecting solar energy, then the instrument collects that reflected energy and records the observation. Most remote sensing systems are designed to collect reflected radiation


Friday, December 19, 2008

Haryana, India to use remote sensing for monitoring drought

Chandigarh, India: Haryana government is planning to use remote sensing satellites for monitoring drought situation in the state, an official spokesman said here.

He said a Memorandum of Understanding (MoU) had been signed between Hisar based Haryana Space Application Centre (HARSAC), an autonomous body of Science and Technology, Haryana and National Remote Sensing Centre (NRSC) Hyderabad to monitor the drought situation at block level.

Advance Wide Image Field Sensor data from resource satellite of India would be used for the purpose, he added. After analysing and interpreting the satellite data acquired at frequent intervals, a monthly bulletin, indicating the situation in each block, would be prepared.

The bulletin would be circulated to all departments so that required contingency measures to save the crops in the susceptible blocks could be taken, he said. He said the project, a milestone in drought management, would be taken up jointly by HARSAC and NRSC for three years after which the technology would be transferred to HARSAC. 


Earth’s Ionosphere drops to a new low

click here to read 

Monday, December 15, 2008

CRRI’s 'Hawk Eye' on Indian roads

At first sight, one can mistake this vehicle to be an ultra tech robotic remote-controlled vehicle, but it is the country's first 'Hawk Eye' that is surveying almost 50,000 kilometres of country's highways and roads to gauge their quality and see if they are fit for freight movement and travel. The database will be used to create GIS maps of highways in the country. The project is being undertaken by Central Road Research Institute (CRRI) and GIS survey and global positioning system (GPS) will help better navigation across the country. 

Mounted on a jeep, the Hawk Eye's instrumentation system includes a laser profiler along with pavement view cameras to measure road surface, collect and process digital images of pavements and other roadside elements. The vehicle has been used in countries like China, Malaysia, Singapore, South Korea and Thailand. Hawk Eye requires high-speed paved roads for operation and is sensitive to rough weather conditions like dust storms and heavy rains. It can gather data while travelling at a speed of 30 to 100 km per hour. 

An advantage Hawk Eye enjoys over other instruments with CRRI is its ability to look at the surface of the road and measure cracking areas. Any area with a crack of above three centimetres is detected by the vehicle's sensors and a preventive measure is suggested by the computers. This helps improve life of highways, which is normally around 20 years in the case of bitumen roads.

Source :

Friday, December 12, 2008

Fishy project to save Indian lake

 Thousands of fish have been released into a picturesque lake in India's northern Nainital in an attempt to restore the areas lost grandeur.

Nainital is a hill resort 2,000 meters above the sea level in Kumaon hills. It's known as the "Switzerland of India" because of its picturesque lakes.

play video


Tuesday, December 9, 2008

ISRO to deploy smaller launchers for LEO satellites

The Indian Space Research Organisation (ISRO) is building a smaller launcher designed to put remote-sensing satellites, weighing less than 500kg, into low earth orbits (LEO). Such launchers will cost 40 per cent less than existing rockets. 

An orbit 400-500km above the earth is designated as a low-earth orbit. Satellites launched into LEOs circle the earth at shorter intervals than their heavier geo-synchronous cousins and so can return to cover a specific point on the planet at shorter intervals. 

The newly designed three stage launcher will cater to the country's military as well as international customers.

"This (launcher) is for strategic reasons. There is also demand from international customers," an ISRO official is quoted as saying. He also said the new launcher would take around six months to build. According to the official, ISRO was developing a variant of its Polar Satellite Launch Vehicle (PSLV). 

The PSLV, Isro's workhorse, can launch satellites of 1.3 tonnes into polar orbits. Since 2007 stripped-down versions of the rocket have carried lighter Israeli and Italian satellites into LEOs. "We had to first send it to polar orbit, burn the rocket for long, before we placed TecSAR in the low (earth) orbit," said another official at the space agency. "That (detour) consumed 60% of the energy of the rocket."

TecSAR is a 300kg Israeli spy satellite which ISRO placed in LEO in January this year. Earlier it had launched a 352kg Italian astronomical satellite Agile in April 2007.

It currently costs Rs100 crore to launch a satellite on a PSLV rocket.

The Indian Air Force's first dedicated satellite intended to gather navigational information will be launched in July next year. The satellite, according to IAF chief ACM Fali H Major, would serve as the force's eye in the skies. 

Source :

Sunday, December 7, 2008

China delays finishing mammoth water project

China has postponed completing a huge water transfer project to quench its national capital's thirst, citing stubborn pollution worries for pushing the target date back four years to 2014, official media said on Saturday.

The South-North Water Diversion scheme will channel water from the Yangtze River and its tributaries to ease shortages across northern China, where population growth and frantic industrialization have drained dams and underground reserves.

The main "central route" stretching 1,267 kms (787 miles) from the Danjiangkou Dam in central Hubei province to Beijing was due to be finished in 2010.

But not now.

Hubei officials said on Friday that pollution and ecological strains in the rivers feeding the dam will make that impossible, Hubei's Changjiang Times said, in a report reprinted by the official Xinhua news agency ( ).

Thursday, December 4, 2008

A global view of HIV infection

llustration: GfK GeoMarketing”

To mark World AIDS Day on December 1, GfK GeoMarketing is provided a map that illustrates the global distribution of HIV cases (data source: WHO/GfK GeoMarketing; map: GfK GeoMarketing).

According to the latest statistics from the World Health Organization (WHO), the highest rates of infection occur in southern Africa and the Russian Federation.


Sunday, November 30, 2008

Key Molecule for Life Found in Our Galaxy

A sugar molecule linked to the origin of life was discovered in a potentially habitable region of our galaxy.

The molecule, called glycolaldehyde, was spotted in a large star-forming area of space around 26,000 light-years from Earth in the less-chaotic outer regions of the Milky Way. This suggests the sugar could be common across the universe, which is good news for extraterrestrial-life seekers.

Wednesday, November 26, 2008

LASER Instrument on Chandrayaan-1 Successfully Turned ON

Lunar Laser Ranging Instrument (LLRI), one of the 11 scientific instruments (payloads) carried by Chandrayaan-1 spacecraft, has successfully been turned ON . The instrument was switched ON when the spacecraft was passing over western part of the moon’s visible hemisphere. Preliminary assessment of the data from LLRI by ISRO scientists indicates that the instrument’s performance is normal. LLRI sends pulses of infrared laser light towards a strip of lunar surface and detects the reflected portion of that light. With this, the instrument can very accurately measure the height of moon’s surface features. LLRI will be continuously kept ON and takes 10 measurements per second on both day and night sides of the moon. It provides topographical details of both polar and equatorial regions of the moon. Detailed analysis of the data sent by LLRI helps in understanding the internal structure of the moon as well as the way that celestial body evolved.

Saturday, November 15, 2008

INTERNATIONAL CONFERENCE On Resource Development and Environmental Change: Emerging Issues and Challenges

Department of Geography,Aligarh Muslim University, Aligarh,India is
organising an INTERNATIONAL CONFERENCE On Resource Development and
Environmental Change: Emerging Issues and Challenges on 27th to 29th
January, 2009. Detail info can be found on

Monday, November 10, 2008

India’s Desi Google Earth on cards

India will soon have a desi version of Google Earth — the popular satellite-mapping tool that allows you to zoom in on any spot on the planet by using just a PC.

ISRO chief G. Madhavan Nair announced this in Gandhinagar yesterday, while inaugurating the Indian National Cartographic Association (INCA)’s International Congress on Collaborative Mapping and Space Technology. Christened “Bhuvan”, the new program will focus on the sub-continent, mapping the upper land surface and the mineral content beneath.

“This will provide the latest information on our natural resources,” said Dr. Nair, adding “and will be useful in addressing local problems like floods, famines, infrastructure development, education and much more”.

Bhuvan will show images 20 times closer than those taken by Google Earth, and they will be upgraded every year. ISRO officials say the requisite software and infrastructure of Bhuvan are already in place and they hope to have it operational by next March.

Friday, November 7, 2008

Chandrayaan-1: first images

It was another proud moment for the country. Prime Minister Manmohan Singh was shown the first pictures that were taken by Chandrayaan-1 through the Terrain Mapping Camera on Friday.The TMC was operated in October through a series of commands, which were issued from the Spacecraft Control Centre of the Indian Space Research Organisation Telemetry, Tracking and Command Network in Bengaluru.The first images, which were received by the Indian Deep Space Network at Byalalu was later processed by the Indian Space Science Data Centre. The first images were taken at 8 am from a height of 9,000 km.The Terrain Mapping camera (TMC) on board Chandrayaan-1 spacecraft was successfully operated on October 29, 2008 through a series of commands issued from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network (ISTRAC) at Bangalore. 

Analysis of the first imagery received by the Indian Deep Space Network (IDSN) at Byalalu and later processed by Indian Space Science Data Centre (ISSDC) confirms excellent performance of the camera.The first imagery (image 1) taken at 8:00 am IST from a height of 9,000 km shows the Northern coast of Australia while the other (image 2) taken at 12:30 pm from a height of 70,000 km shows Australia’s Southern Coast. 

TMC is one of the eleven scientific instruments (payloads) of Chandrayaan-1. The camera can take black and white pictures of an object by recording the visible light reflected from it. The instrument has a resolution of about 5 metres.

Links: ISRO

Rediff News

Tuesday, November 4, 2008

Chandrayaan-1 enters Lunar Transfer Trajectory

The fifth and final orbit raising manoeuvre of Chandrayaan-1 spacecraft was successfully carried out today (November 4, 2008) morning at 04:56 am IST. During this manoeuvre, the spacecraft’s 440 Newton liquid engine was fired for about two and a half minutes. With this, Chandrayaan-1 entered the Lunar Transfer Trajectory with an apogee (farthest point to Earth) of about 380,000 km (three lakh eighty thousand km). 

The health of the spacecraft is being continuously monitored from the Spacecraft Control Centre at ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bangalore with support from Indian Deep Space Network (IDSN) antennas at Byalalu. Since its launch on October 22 by PSLV-C11, all systems onboard Chandrayaan-1 spacecraft are performing normally. Chandrayaan-1 will approach the Moon on November 8, 2008 and the spacecraft’s liquid engine will be fired again to insert the spacecraft into lunar orbit.

Tuesday, October 28, 2008

Rising CO2 accelerates coral bleaching: study

Rising carbon dioxide levels in the world's oceans due to climate change, combined with rising sea temperatures, could accelerate coral bleaching, destroying some reefs before 2050, says a new Australian study.

The study says earlier research may have significantly understated the likely damage to the world's reefs caused by man-made change to the Earth's atmosphere.

"Previous predictions of coral bleaching have been far too conservative, because they didn't factor in the effect of acidification on the bleaching process and how the two interact," said Professor Ove Hoegh-Guldberg from the ARC Center of Excellence for Coral Reef Studies and Queensland University.

Wednesday, October 22, 2008

India on the moon: Chandrayaan-1 successful

Chandrayaan-1, India’s maiden moon spacecraft, was put into Transfer Orbit around the earth by the Polar Launch Vehicle PSLV-C11 after it blasted off from the Satish Dhawan Space Centre.

The 1,380 kg Chandrayaan-1, carrying 11 payloads, was released into a Transfer Orbit 18.2 minutes after the PSLV-C11 blasted off.

full post

Japan launches voluntary CO2 market

Japan on Tuesday launched a voluntary carbon market based on companies' pledged emissions cuts and hopes thousands of firms will sign up to what could become a forerunner of a mandatory cap-and-trade scheme.

The scheme, once it's up and running by next year, is expected to be the nation's broadest emissions market. But some said the scheme still fell short of what Japan needed to make deep emissions cuts and could backfire.

The trial over-the-counter market is aimed at accelerating further cuts in the private sector via new technologies to save energy and reduce or remove emissions from the atmosphere, Environment Minister Tetsuo Saito told reporters.

"It's based on a voluntary (cap) because we'd like to see as many companies as possible joining in as we start. But we're aiming to make it a cap-and-trade scheme eventually," he said.

"We're hoping to accept applications from thousands or even tens of thousands of companies, ranging from big companies to medium to small ones as well as mainstay companies in each region," he added.

Japan, the world's fifth-largest greenhouse gas emitter, has been reluctant to impose a mandatory cap on companies' emissions because of past efforts by industry to clean up and become more efficient.

Japan is one of the world's most energy-efficient countries. But like all rich nations, it has come under increasing pressure from developing nations to pledge deeper cuts to its emissions as part of a broader U.N.-led fight against climate change.

Saturday, October 18, 2008

Beluga whales in Alaska listed as endangered

The depleted population of beluga whales that swim off the coast of Alaska’s largest city was listed as endangered on Friday by the federal government.

Alaska Gov. Sarah Palin, the Republican vice-presidential candidate, called the listing “premature” after she had pressed for more time to make beluga population counts.

Environmentalists hailed the listing decision, but criticized the time it took to materialize.

“Hopefully the State of Alaska will now work toward protecting the beluga rather than, as with the polar bear, denying the science and suing to overturn the listing,” Brendan Cummings, oceans program director for the Center for Biological Diversity said in a statement.

The National Oceanic and Atmospheric Administration said it has determined that belugas in Cook Inlet, the channel that flows from Anchorage to the Gulf of Alaska, are at risk of extinction and deserving of strict protections under the Endangered Species Act.

The population, which fell to a low of 278 in 2005 from 653 in 1994, has yet to rebound from a period of over-harvesting by the region’s Native hunters, officials said.

Hunting of Cook Inlet belugas largely ceased in 1999, but the population continues to struggle, officials said.

“In spite of protections already in place, Cook Inlet beluga whales are not recovering,” James Balsinger, acting assistant administrator for NOAA’s Fisheries Service, said in a statement.


Tuesday, October 14, 2008

Ban on commercial use of GPS in Egypt

Technology lovers and modern car owners in Egypt consider themselves unlucky because of a government ban on the usage of Global Positioning System (GPS) technology. 

Telecoms Law 10/2003 outlaws the import of GPS-equipped mobile phones, and retailers found selling them could lead to the confiscation of their entire stock. The same applies to any kind of commercial use of GPS technology, which includes cars equipped with GPS devices.

Mobile phones like the Nokia N95, N82 as well as iPhones and some 3G phones are banned in Egypt, leaving the market deprived of the latest technology and features that are fast becoming standard in the new generation of mobile phones.

Monday, October 6, 2008

Think India Think, Are We Civilized Enough?

India is progressing fast indeed. But, Perhaps we are not civilized enough. It is time to introspect and to contemplate. I have found a very thought provoking post at Amit's Blog.


Mother?! India?!

Saturday, October 4, 2008

CERN unveils computer grid linking 7,000 scientists

CERN, the world's biggest particle physics laboratory and creator of the Worldwide Web, on Friday unveiled a new computer network allowing thousands of scientists around the world to crunch data on its huge experiments.

Some 7,000 scientists in 33 countries are now linked through the computing network at CERN, the European Organization for Nuclear Research, to analyze data from its particle-smashing test probing the nature of matter that began last month.

That experiment, which could provide clues about the origins of the universe, began on September 10 and was shut down nine days later because of a helium leak in the 27 km (17 mile) tunnel of CERN's Large Hadron Collider (LHC).

Monday, September 29, 2008

World's Biggest Atlas

Copies of the largest world atlas ever produced have gone on sale at an earth-shattering price of £2,000 each.

Dubbed “the ultimate book about our world”, the luxurious, limited edition Earth is hand-bound in leather with gilded edges and silver-plated corners.

The atlas and its case together weigh 30kg – more than the maximum many airlines set passengers for their baggage allowance.

The 576 pages contain 154 maps and 800 photographs backed with detailed descriptions of every country’s geography, history and culture. Lying closed, the atlas takes up a third of a square metre with four gatefolds opening out to two square metres each.

Ten cartographic experts at the British map company Global Mapping spent eight months compiling Earth with more than 100 overseas colleagues including fellow map makers, geographers and oceanographers. They worked with detail from a continuously updated world database of digital mapping.

Global Mapping’s Alan Smith said: “We all had to keep to the same, consistent specification to make sure everything tied in universally from the way we shaded hills to the presentation of political geography. The sheer physical size of the atlas is amazing. The overall content, including the maps, text and photographs, is very much more detailed than any other atlas ever produced.”

Only 3,000 hand-numbered copies of Earth have been made – one for every 3.3 million people in the world. The atlas is expected to appeal to specialist collectors, libraries, rich individuals with a penchant for mapping and companies seeking lavish, once-in-a-lifetime corporate gifts. Taking the exclusive level even higher, one thousand copies from the print run have had their covers redone in gold leather with gold plated corners at the request of distributors in the Middle East.

Earth is the brainchild of Australian map publisher Gordon Cheers who has already received several hundred orders for copies. He described it as “a time capsule of where we are in the world today”.

The atlas may be impressive but its 30kg weight still pales into insignificance when compared to the mass of the planet itself – estimated at an unpronounceable 6,000,000,000,000,000,000,000,000 kg.

Earth can be order via Worlds Biggest Atlas

Global Mapping publishes a range of wall maps and supplies maps for travel guides, book packaging, planning applications and many other activities in business, government and leisure. Based in Northamptonshire, the company has a wealth of experience in mapping for print, CD, GIS and Internet.

Global Warming:Europe is warming faster...

click here 

Friday, September 26, 2008

Climate Change - Cities Are The Solution, Not The Problem

Cities are unfairly blamed for greenhouse gas emissions by misguided politicians and well-meaning people who listen to them, and this threatens efforts to truly impact climate change, warns a study in the October 2008 issue of the journal Environment and Urbanization. The paper says cities are commonly blamed for 75 to 80 percent of emissions but that the true value is around half that and the potential for cities to help address climate change is being overlooked because of this error. 

United Nations agencies, former US President Bill Clinton’s climate change initiative and New York Mayor Michael Bloomberg have all claimed that between 75 and 80 per cent of emissions come from cities even though data from the Intergovernmental Panel on Climate Change (IPCC) shows that only 40 percent of all greenhouse gases are from human activities generated within cities.

“Blaming cities for greenhouse gas emissions misses the point that cities are a large part of the solution,” says the paper’s author, David Satterthwaite, a Senior Fellow at the International Institute for Environment and Development (IIED). “Well planned, well governed cities can provide high living standards that do not require high consumption levels and high greenhouse gas emissions.”

Satterthwaite says agriculture and deforestation account for another 30 percent of greenhouse gas emissions and the final 30 percent are from heavy industry, coal, oil or gas fuelled power stations located in non-metropolitan areas and wealthy households, like politicians live in when they are misstating data.

The paper also highlights how it can be misleading to allocate greenhouse gas emissions to places at all. For instance, emissions from power stations should be allocated to those that consume the electricity, not the places where the power stations are located. Emissions generated by industries would therefore be shared by the person consuming the goods the industries produce. 

“Consumer demand drives the production of goods and services, and therefore the emission of greenhouse gases,” says Satterthwaite. “Allocating emissions to consumers rather than producers shows that the problem is not cities but a minority of the world’s population with high-consumption lifestyles. A large proportion of these consumers live not in cities but in small towns and rural areas.” 

Allocating greenhouse gas emissions to consumers increases the share of global emissions from Europe and North America, which makes self-loathing activists happy, but also clarifies the very low emissions per person of most city inhabitants in Africa, Asia and Latin America.

In general, wealthy people outside cities are responsible for more greenhouse gas emissions than those in cities as they have larger homes that need to be heated or cooled, more automobiles per household and greater automobile use.

“The way cities are designed and run can make a big difference,” says Satterthwaite. “Most cities in the United States have three to five times the gasoline use per person of most European cities but not three to five times the living standards.”

Satterthwaite points out that cities offer many opportunities to reduce per capita greenhouse gas emissions, such as by promoting walking, bicycling and public transport and having building designs that require much less energy for heating and cooling.

“Achieving the needed reductions in greenhouse gas emissions worldwide depends on seeing and acting on the potential of cities to combine a high quality of life with low greenhouse gas emissions,” he says.

Thursday, September 25, 2008

The freshwater biome

Freshwater is defined as having a low salt concentration — usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e., ocean). There are different types of freshwater regions:

Ponds and lakes
Streams and rivers


Saturday, September 20, 2008

The Birth of Eart's Moon: Giant Impact Theory

At the time Earth formed 4.5 billion years ago, other smaller planetary bodies were also growing. One of these hit earth late in Earth’s growth process, blowing out rocky debris. A fraction of that debris went into orbit around the Earth and aggregated into the moon.

The Giant Impact, as pictured in a painting by William K. Hartmann on the cover of Natural History Magazine in 1981. Copyright William K. Hartmann

Half an Hour After the Giant Impact, based on computer modeling by A. Cameron, W. Benz, J. Melosh, and others. Copyright William K. Hartmann

Five Hours After Impact, based on computer modeling by A. Cameron, W. Benz, J. Melosh, and others. Copyright William K. Hartmann

read full post

Wednesday, September 17, 2008

World's glaciers facing huge threat: UN

The United Nations said  that swathes of mountain ranges worldwide risk losing their glaciers by the end of the century if global warming continues at its projected rate.

The UN Environment Programme (UNEP) said in a report that whilst nature has always observed a certain periodic rate of deglaciation, the current trends observed from the Arctic to Central Europe and South America are of a different order.

"The ongoing trend of worldwide and rapid, if not accelerating, glacier shrinkage on the century time scale is most likely to be of a non-periodic nature, and may lead to the deglaciation of large parts of many mountain ranges by the end of the 21st century," the report warned.

Tuesday, September 9, 2008

GeoEye-1 successfully launched - now see the world better than ever

USA - GeoEye-1 the super-sharp Earth-imaging satellite was launched into orbit on 6th of September from Vandenberg Air Force Base on the Central California coast. A Delta 2 rocket carrying the GeoEye-1 satellite lifted off at 11:50 a.m. Video on the GeoEye Web site showed the satellite separating from the rocket moments later on its way to an eventual polar orbit. 

The satellite makers say GeoEye-1 has the highest resolution of any commercial imaging system. It can collect images from orbit with enough detail to show home plate on a baseball diamond. The company says the satellite's imaging services will be sold for uses that could range from environmental mapping to agriculture and defense. 

GeoEye-1 was lifted into a near-polar orbit by a 12-story-tall United Launch Alliance Delta II 7420-10 configuration launch vehicle. The launch vehicle and associate support services were procured by Boeing Launch Services. The company expects to offer imagery and products to customers in the mid- to late-October timeframe.
The GeoEye-1 Satellite

GeoEye-1, designed and built by General Dynamics Advanced Information Systems, is the world's highest resolution commercial imaging satellite. Designed to take color images of the Earth from 423 miles (681 kilometers) in space and moving at a speed of about four-and-a-half miles (seven kilometers) per second, the satellite will make 15 earth orbits per day and collect imagery with its ITT-built imaging system that can distinguish objects on the Earth's surface as small as 0.41-meters (16 inches) in size in the panchromatic (black and white) mode. The 4,300-pound satellite will also be able to collect multispectral or color imagery at 1.65-meter ground resolution. While the satellite will be able to collect imagery at 0.41-meters, GeoEye's operating license from NOAA requires re-sampling the imagery to half-meter resolution for all customers not explicitly granted a waiver by the U.S. Government.

The satellite will be able to see an object the size of home plate on a baseball diamond but also map the location of an object that size to within about nine feet (three meters) of its true location on the surface of the Earth without need for ground control points. Together, GeoEye's IKONOS and GeoEye-1 satellites can collect almost one million square kilometers of imagery per day.

With the ability to revisit any location on the globe every three days, and at lesser resolution more frequently, GeoEye-1 will enable customers to receive imagery updates on a regular basis and is ideal for large-scale mapping projects. This capability will benefit a broad array of industries including national defense and intelligence, online mapping, state and local governments, environmental monitoring and land use management, oil and gas, utilities, disaster management, insurance and others. 

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Sunday, September 7, 2008

Simple Actions to Reduce Global Warming

The future is not somewhere we are going. It is something we are creating. Every day we do things that make some futures more probable and others less likely.

Global warming already disrupts millions of lives daily in the forms of destructive weather patterns and loss of habitat. What is already happening is only the tip of the melting iceberg, for it is our children and grandchildren who may suffer most from the effects of global warming. Hundreds of millions of people may be exposed to famine, water shortages, extreme weather conditions and a 20 - 30% loss of animal and plant species if we don’t reduce the rate of global warming and reduce GHG emissions.This article outlines some ways that you can act to help prevent the Earth from warming further. While humankind has the ability to destroy the planet, we can also help protect and sustain it.
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Friday, September 5, 2008

Iran launch of Omid successful

Iran announced Sunday that it launched a satellite into space earlier in the day, the country’s first domestically made.

The satellite, Omid (hope), was launched Sunday by using Safir (ambassador) satellite-carrier rocket, the armed forces said in a statement, quoted by the official IRNA news agency.

The Omid Satellite which was successfully fired on the birth anniversary of the last Imam (prophet) of Shiites, Hazrat Mahdi (who is believed to reappear at the end of the world) illustrated the auspicious name of the Imam in the space, IRNA said.

According to Iran’s English-language Press TV satellite channel, the domestically manufactured Omid Satellite will pass over the country six times a day.

The launch of Safir rocket aimed to test remote sensing, satellite telemetry, and geographic information system (GIS) technology as well as remote and ground station data processing, Press TV said.

Another news agency Fars quoted government spokesman Gholam- Hossein Elham as saying that President Mahmoud Ahmadinejad was at the launch of the communications satellite from Iran’s space station.

In February, Iran said it has prepared for the satellite launch by sending a probe into space of a rocket on the mission.

Ahmadinejad announced in his press interview in Istanbul Friday that Iran would in near future launch its first domestic satellite to the space.

Iran, embroiled in a standoff with the West over its disputed nuclear ambitions, has pursued a space program for several years, according to media reports.

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Tuesday, September 2, 2008

Isro,India to launch Italian, Algerian satellites

India - Antrix Corp. Ltd, the commercial arm of India’s space agency, has won a pair of deals from Algeria and Italy to launch earth observation satellites next year on the polar satellite launch vehicle, or PSLV, its workhorse rocket. 

The contract awarded by the Algerian space agency to launch Alsat-2A, a 200kg remote sensing satellite, is the first won by Antrix from an African nation. The Algerian agency has the option to launch a second such satellite. For the Italian space agency Agenzia Spaziale Italiana, Antrix will launch a satellite named IMSAT, which will be the second Italian satellite to be boosted into space by the Indian Space Research Organisation, or ISRO, which in April 2007 launched Agile, a 352kg scientific satellite. 

The Algerian and Italian satellites, besides a 100kg satellite for Nanyang Technological University in Singapore, and Cubesat, a three-satellite package from the Netherlands, would ride piggyback on heavier Indian satellites, said K.R. Sridhara Murthi, managing director of Antrix. He didn’t disclose financial details.

Antrix is also in talks with space agencies of South Africa and Nigeria to carry out similar launches, Murthi said. “We are also looking at opportunities bigger than that—remote sensing satellites, where payloads (are) of 800kg or even higher.” 

ISRO offers the home-grown PSLV to carry satellites of up to 1,700kg into low-earth orbit at a cost that’s nearly 30% cheaper than that charged by firms such as International Launch Services, owned by Space Transport Inc. and two Russian organizations, Khrunichev State Research and Production Space Center and RSC Energia. Low-earth orbit is the region above earth between 200km and 2,000km, ideal to place earth observation or remote sensing satellites. 

India is still a fledgling competitor in the global satellite manufacturing and launch industry, which is expected to grow to $145 billion (Rs6.3 trillion) over 10 years to 2016, from $116 billion in the 10 years to 2006, according to Paris-based research firm Euroconsult.

“(ISRO’s) benchmark is with international specifications on quality, reliability and credibility of the systems. And then, you are also cost competitive,” said K. Kasturirangan, director of the National Institute of Advanced Studies, a think tank in Bangalore. “The opportunity is just growing.” 

Source :

Thursday, August 28, 2008

Cut greenhouse gases to save coral reefs: scientists

To keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere, a panel of marine scientists said on Wednesday.

"The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the scientists said in a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

Ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching, the scientists said.

Coral reefs are a "sentinel ecosystem," a sign that the environment is changing, said one of the experts, Billy Causey of the U.S. National Marine Sanctuary Program.

"Although ocean acidification is affecting the health of our oceans, the same thing -- increased carbon dioxide in the atmosphere -- is going to in fact be affecting terrestrial environments also," Causey said by telephone from Hawaii.

Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue, the declaration said.

But corals are increasingly threatened by warming sea surface temperatures as well as ocean acidification.

Oceans are getting more acidic because they have been absorbing some 525 billion tons of the greenhouse gas carbon dioxide over the last two centuries, about one-third of all human-generated carbon dioxide for that period.

The carbon dioxide combines with sea water to form carbonic acid.

Marine researchers have long recognized acidification in deep ocean water far from land, but a study published this year in the journal Science found this same damaging phenomenon on the Pacific North American continental shelf from Mexico to Canada, and quite likely elsewhere around the globe.

The water became so corrosive that it started dissolving the shells and skeletons of starfish, clams and corals.

Stabilizing carbon dioxide emissions was the Honolulu Declaration's top long-term recommendation. The key short-term recommendation was to nurture coral reefs that seem to have natural resilience against acidification.

This could be adopted immediately by managers of protected marine areas, Causey said.

The Honolulu Declaration will be presented to the United Nations and to other global, regional and national forums.

Monday, August 25, 2008

Finding You on a Map

By far the easiest way to determine where you are on a map is to pull out your pocket GPS (global positioning system receiver) and have it give you your map coordinates. If, however, you are like a lot of people, you don’t want to shell out a few hundred bucks for a GPS and, unless you are in an area with very little topographic relief, you don’t need one. You can determine your position quite accurately on a topographic map by using your compass to triangulate between three points.

The first step in triangulation is to pick three topographic features that you can see and can identify on your map (mountains are ideal). Start with the first feature you have chosen and determine the bearing between you and it, as outlined above. Once you have determined its bearing, pencil in a line with the same bearing on your map that runs through the chosen feature (having a protractor would be useful).

Repeat this for the other two features, drawing lines for each. The point where the three lines intersect on the map is where you are. Depending on how accurate your sightings were and how accurately you drew your lines through the features, there will probably be a some error in your location. Be sure to double check the map and reconcile it with what you see. If the lines intersect in a valley and you are on a hill, the location is obviously off a bit on the map.

Wednesday, August 20, 2008

Map Projections and Distortions

What is a Map?

Once a reference datum has been determined the elevation of any point can be accurately determined, and it will correlate to the elevation of any point on the earth's surface that has the same elevation and is using the same datum. But…how do you accurately represent the X and Y coordinates of that point? This question leads to one of the fundamental problems of mapmaking…how do you represent all or part of an ellipsoid object on a flat piece of paper? The answer to this question is a bit complicated, but understanding it is fundamental to understanding what maps actually represent (this statement will become clearer shortly).
In order to represent the surface of the earth on a flat piece of paper, the map area is projected onto the paper. There are many different types of projections, each with its own strengths and weaknesses.

The simplest (and easiest to visualize) example of a projection is a planar projection. To understand this type of projection, imagine inserting a piece of paper through the earth along the equator. Now imagine that the earth is semi-transparent and you could shine a flashlight oriented along the (geographic) polar axis through the earth.

The resulting outline on the paper would be a map created using this type of projection (known as a transverse azimuthal or planar projection).

There are three main types of projections, based on the shape of the 'paper' onto which the earth is projected. The example above used an azimuthal (planar) piece of paper.


The other main types, illustrated to the right, are cylindrical and conical projections. These three types of projections can be further modified by the way the 'paper' is oriented when it is inserted into the earth.

In the example above, the plane was oriented along the equator, known as a transverse orientation (hence the 'transverse azimuthal' projection). Projections may also be equatorial (oriented perpendicular to the plane of the equator) or oblique (oriented at some angle that is neither parallel nor perpendicular to the plane of the equator.

Map Projection Distortions

Each of the different types of projections have strenghts and weaknesses. Knowledge of these different advantages and disadvantages for a particular map projection will often help in which map to choose for a particular project. The basic problem inherent in any type of map projection is that it will result in some distortion of the ‘ground truth’ of the area being mapped.

There are four basic characteristics of a map that are distorted to some degree, depending on the projection used. These characteristics include distance, direction, shape, and area. The only place on a map where there is no distortion is along the trace of the line that marks the intersection of our ‘paper’ with the surface of the earth.

Any place on the map that does not lie along this line will suffer some distortion. Fortunately, depending on the type of projection used, at least one of the four characteristics can generally be preserved.
A conformal projection primarily preserves shape, an equidistant projection primarily preserves distance, and an equal-area projection primarily preserves area.

These image show the earth using different projections. Notice how the continents look stretched or squashed depending on the projection. Following are some websites with more information.


Sunday, August 17, 2008


The geoid is that equipotential surface which would coincide exactly with the mean ocean surface of the Earth, if the oceans were in equilibrium, at rest, and extended through the continents (such as with very narrow canals). According to C.F. Gauss, who first described it, it is the “mathematical figure of the Earth,” a smooth but highly irregular surface that corresponds not to the actual surface of the Earth’s crust, but to a surface which can only be known through extensive gravitational measurements and calculations. Despite being an important concept for almost two hundred years in the history of geodesy and geophysics, it has only been defined to high precision in recent decades, for instance by works of P. Vaníček and others. It is often described as the true physical figure of the Earth, in contrast to the idealized geometrical figure of a reference ellipsoid.

Friday, August 15, 2008

Congratulations India

With all the inherent contradictions and weaknesses we Indians have an intense desire to succeed,to march ahead and to excel. This is our secret of suceess.Happy Independence Day to fellow Indians.

Wednesday, August 13, 2008

ISRO postpones Chandrayaan I until mid-October

India - The launch of India's first unmanned mission to the Moon has been postponed until the middle of October, the head of the Indian space program has said. 

The launch of the Chandrayaan I lunar orbiter by the Indian Space Research Organization (ISRO) was originally planned for September 19 but scientists have yet to conduct the thermo-vacuum testing of a Polar Satellite Launch Vehicle (PSLV) with the orbiter on board.
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Monday, August 11, 2008

Congratulations Abhinav

India's Abhinav Bindra won a gold in men's 10-metre Air Rifle event in Beijing. Bindra shot 104.5 to take his total to 700.5 in the final. This is India's first ever Olympic gold in any individual event and ninth in total.

In ten rounds, Bindra shot 10.7, 10.3, 10.4, 10.5, 10.5, 10.5, 10.6, 10.0, 10.2, 10.8 to clinch the first berth. China's Qinan Zhu won silver while Finland's Henri Hakkinen won bronze.

Bindra had shot a total of 596 out of 600, shooting a perfect 100 in 3 of the 6 rounds of the qualifiers. Bindra finished 4th to qualify 2 points behind Henri Hakkinen of Finland. 

Gagan Narang, meanwhile, was very unlucky missing out by just 1 point on a countback after he was tied with 4 others after 6 rounds with an average score of 9.917 in the qualifiers. In a countback, since all five shooters, who were tied, had shot a perfect 100 in the last round, the 5th round scores were taken into account, where Narang had managed a 98, whereas the others had shot either a 99 or a 100. 

If Narang had shot a 99 instead of a 98, 4th round scores would have been taken into account and Narang would have gone through.

Friday, August 8, 2008

The Atomic Bombs, End of World War II and Begining of Nuclear Age

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Bulgarian archaeologists discover ancient chariot

SOFIA, Bulgaria - Archaeologists have unearthed a 1,900-year-old well-preserved chariot at an ancient Thracian tomb in southeastern Bulgaria, the head of the excavation said Thursday.
Daniela Agre said her team found the four-wheel chariot during excavations near the village of Borisovo, around 180 miles east of the capital, Sofia.
"This is the first time that we have found a completely preserved chariot in Bulgaria," said Agre, a senior archaeologist at the Bulgarian Academy of Sciences.
She said previous excavations had only unearthed single parts of chariots — often because ancients sites had been looted.
At the funerary mound, the team also discovered table pottery, glass vessels and other gifts for the funeral of a wealthy Thracian aristocrat.
In a separate pit, they unearthed skeletons of two riding horses apparently sacrificed during the funeral of the nobleman, along with well preserved bronze and leather objects, some believed to horse harnesses.
The Culture Ministry confirmed the find and announced $3,900 in financial assistance for Agre's excavation.
Agre said an additional amount of $7,800 will be allocated by the Bulgarian Academy of Sciences for an initial restoration and conservation of the chariot and the other Thracian finds.
The Thracians were an ancient people that inhabited the lands of present day Bulgaria and parts of modern Greece, Turkey, Macedonia and Romania between 4,000 B.C. and the 6th century, when they were assimilated by the invading Slavs.
Some 10,000 Thracian mounds — some of them covering monumental stone tombs — are scattered across Bulgaria.

Wednesday, August 6, 2008

Phoenix detected Perchlorate in Soil of Mars

Photo credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 43, the 43rd Martian day after landing (July 8, 2008). This image shows the trench informally called "Snow White." 

Two samples were delivered to the Wet Chemistry Laboratory, which is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The first sample was taken from the surface area just left of the trench and informally named "Rosy Red." It was delivered to the Wet Chemistry Laboratory on Sol 30 (June 25, 2008). The second sample, informally named "Sorceress," was taken from the center of the "Snow White" trench and delivered to the Wet Chemistry Laboratory on Sol 41 (July 6, 2008).

  Mars mission scientists spoke today on research in progress concerning an ongoing investigation of perchlorate salts detected in soil analyzed by the wet chemistry laboratory aboard NASA's Phoenix Lander. 

"Finding perchlorates is neither good nor bad for life, but it does make us reassess how we think about life on Mars," said Michael Hecht of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead scientist for the Microscopy, Electrochemistry and Conductivity Analyzer (MECA), the instrument that includes the wet chemistry laboratory. 

If confirmed, the result is exciting, Hecht said, "because different types of perchlorate salts have interesting properties that may bear on the way things work on Mars if -- and that's a big 'if ' -- the results from our two teaspoons of soil are representative of all of Mars, or at least a significant portion of the planet." 

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Tuesday, August 5, 2008

Iran tests 'new weapon' for use at sea

TEHRAN, Iran - Iran announced Monday that it has tested a new weapon capable of sinking ships nearly 200 miles away, and reiterated threats to close a strategic waterway at the mouth of the Persian Gulf if attacked.  

Up to 40 percent of the world's oil passes through the Strait of Hormuz, a narrow passage along Iran's southern coast. Tehran has warned it could shut down tanker traffic there if attacked — a move likely to send oil prices skyrocketing.

The warnings came two days after a deadline expired for Iran to respond to incentives from six world powers, offered in exchange for a promise to curb its uranium enrichment.

Later Monday, the U.S. State Department said the group — the five permanent members of the U.N. Security Council, plus Germany — agreed to pursue further sanctions against Iran because of its failure to meet the Saturday deadline.

Iran and the West have been mired in a standoff over the country's disputed nuclear program. The United Nations has already slapped Iran with three rounds of sanctions, over its refusal to stop enriching uranium — a key process that generates either fuel for a nuclear reactor, or the fissile material for a bomb.

Iran says its nuclear program is for peaceful purposes only, to generate electricity.

Revolutionary Guards commander Gen. Mohammad Ali Jafari said Monday that the new marine weapon is "unique in the world" and has a range of 300 kilometers (186 miles), according to the state news agency IRNA.

That's within range of U.S. warships deployed in the Persian Gulf. Last month, Iran tested missiles it claimed were capable of reaching 1,250 miles (2,000 kilometers) away — putting U.S military bases in the Middle East as well as Israel, Turkey, the Arabian peninsula, Afghanistan and Pakistan all within striking distance.

Monday's report gave no details on when or where the new weapon was tested. Its range indicates it could be a type of torpedo, but state radio called it a missile.

Jafari warned Iran would respond decisively if any military strike is carried out against it.

"Enemies know that we are easily able to block the Strait of Hormuz for an unlimited period," he was quoted by state radio as saying. "The strait and vessels are in range of our various weapons."

Both the U.S. and Israel — which shares American concerns over Iran's nuclear program — have said they would prefer a diplomatic solution to the standoff with Iran, but have not ruled out other options — including a military one.

Israeli analyst Ephraim Kam, a former senior intelligence officer, dismissed the new weapons test.

"They are always boasting about their weapons and their military capabilities and saying how unique they are, but they are usually just standard military weapons," he said.

Monday, August 4, 2008

Bangladesh gaining land, not losing: Scientists

New data shows that Bangladesh's landmass is increasing, contradicting forecasts that the South Asian nation will be under the waves by the end of the century, experts say. 

Scientists from the Dhaka-based Center for Environment and Geographic Information Services (CEGIS) have studied 32 years of satellite images and say Bangladesh's landmass has increased by 20 square kilometres (eight square miles) annually. 

Maminul Haque Sarker, head of the department at the government-owned centre that looks at boundary changes, said sediment which travelled down the big Himalayan rivers the Ganges and the Brahmaputra -- had caused the landmass to increase. 

The rivers, which meet in the centre of Bangladesh, carry more than a billion tonnes of sediment every year and most of it comes to rest on the southern coastline of the country in the Bay of Bengal where new territory is forming, he said in an interview on Tuesday. 

The United Nations Intergovernmental Panel on Climate Change (IPCC) has predicted that impoverished Bangladesh, criss-crossed by a network of more than 200 rivers, will lose 17 per cent of its land by 2050 because of rising sea levels due to global warming. 

The Nobel Peace Prize-winning panel says 20 million Bangladeshis will become environmental refugees by 2050 and the country will lose some 30 per cent of its food production. 

Director of the US-based NASA Goddard Institute for Space Studies, professor James Hansen, paints an even grimmer picture, predicting the entire country could be under water by the end of the century. 

But Sarker said that while rising sea levels and river erosion were both claiming land in Bangladesh, many climate experts had failed to take into account new land being formed from the river sediment.

"Satellite images dating back to 1973 and old maps earlier than that show some 1,000 square kilometres of land have raised from the sea," Sarker said. 

"A rise in sea level will offset this and slow the gains made by new territories, but there will still be an increase in land. We think that in the next 50 years we may get another 1,000 square kilometres of land." 

Mahfuzur Rahman, head of Bangladesh Water Development Board's Coastal Study and Survey Department, has also been analysing the buildup of land on the coast. 

He said findings by the IPCC and other climate change scientists were too general and did not explore the benefits of land accretion. 

"For almost a decade we have heard experts saying Bangladesh will be under water, but so far our data has shown nothing like this," he said. 

"Natural accretion has been going on here for hundreds of years along the estuaries and all our models show it will go on for decades or centuries into the future." 

Dams built along the country's southern coast in the 1950s and 1960s had helped reclaim a lot of land and he believed with the use of new technology, Bangladesh could speed up the accretion process, he said. 

"The land Bangladesh has lost so far has been caused by river erosion, which has always happened in this country. Natural accretion due to sedimentation and dams has more than compensated this loss," Rahman said. Bangladesh, a country of 140 million people, has built a series of dykes to prevent flooding. 

"If we build more dams using superior technology, we may be able to reclaim 4,000 to 5,000 square kilometres in the near future," Rahman said. 

Source :

Olympics:Haze returns to Beijing with four days to go

A grey haze clogged Beijing's skies on Monday as the city returned to work after a weekend of the clear weather, just four days before the opening ceremony for the Olympic Games.

Beijing's chronic pollution has been one of the biggest headaches for organizers who have closed dozens of factories and pulled more than half the city's 3.3 million cars off the roads in a bid to ensure blue skies during the competition.

Officials said China was still considering some man-made help to ensure dry weather and clean air for Friday.

China has two methods of controlling rainfall. Weather stations outside Beijing could try to induce rain before it reaches the centre of the city, by firing a chemical seeding agent into clouds with anti-aircraft guns, a common practice in arid northern China.

Or it could fire a coolant into clouds that increases the number of water droplets, causing heavier droplets to fall ahead of the big show.

Smog shrouded the city for much of last week, prompting the government to draw up a last-resort plan to clear more vehicles from the roads of Beijing and surrounding cities, and shut down over 200 more factories.

The International Olympic Committee (IOC) has said it may reschedule endurance events such as the marathon to prevent health risks if pollution is bad.

Data from the Beijing Environmental Protection Bureau showed that air pollutants were well within limits for a "blue sky day" at all monitoring stations in the 24 hours to midday on Sunday, although they do not provide an overall summary.

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Thursday, July 31, 2008

Ancient India:Maps

One of the readers asked for the map of ancient india. 
The history of India is shrouded in antiquity. The country has been thought of as a nation of philosophers with a well-developed and even idyllic society. Excavations of sites belonging to the Harappan era show that the people lived in brick houses in towns with excellent drainage. One of the oldest scriptures in the world is the four volume Vedas that many regard as the repository of national thoughts that anticipated some of the modern scientific discoveries. Despite formidable barriers in the form of the mighty Himalayas and oceans, India also received a succession of foreigners, many of them carrying swords and guns. But nearly all of them stayed on. Out of these waves of immigration has emerged the composite culture of India and made it a land of unity in diversity. India became a land of assimilation and learning, a land of change and continuity. According to the one school of thoughts, the Aryans were among the first to arrive in India, which was inhabited by the Dravidians. Others who came here included Greeks, Persians, Mughals and even British, Portuguese and French. Over the years there have been many major ruling dynasties like the Shakas, the Kushans, the Maurayas and Guptas. Nearly every major religion in the world is represented in India. It is also the land of Lord Buddha, Lord Mahavira and Guru Nanak Dev, the founders of Buddhism, Jainism and Sikhism.