Thematic Maps serve an important source of GIS information. A thematic map is a map used to convey geographical information such as climate, density of population, land use and other geographical aspects of any city, region, state or country. Thematic maps also known as geographic assays use/utilize base data of places and coastlines as a reference point and then draw out the inferences.
Thematic maps are used not only for showing the distribution of different attributes but they also depict relationship between different attributes also. Similar to dynamic mapping, thematic mapping enables a geographer to update/change mapping elements and view the changes as they happen. Thematic maps are very useful because they provide information about locations, outline the relationships between different attributes and the charts made can be used for navigational purpose as well.
The origin of thematic maps can be traced back to 1686, when Edmond Halley (an English astronomer) published a map known as terrestrial map. This map can be called as the earliest map that came into existence. However, the obvious use of thematic mapping first came out in 1854, when John Snow, a physician from London utilized thematic principles for devising a map for analyzing the spread of cholera in a particular area. Since then, these thematic maps have been used regularly for getting information about a particular area.
While making a map, the cartographer needs to be careful of portraying the data on the map in such a manner that the audience can understand it very carefully. The cartographer needs to examine the location or the physical area and thereafter collect the data sets. Although the general principle remains the same but there are different techniques for mapping a particular area. Choropleth is the most frequently used method for thematic mapping. In case of Proportional symbols the area or the information is represented with the help of point locations.
In Isarithmic method, the maps are used for depicting smooth continuous phenomena such as precipitation etc. In the Dot method, a particular feature or occurrence is used for displaying a spatial pattern. Dasymetric maps make use of areal symbols. However, although boundaries are displayed on dasymetric maps, these geographic units may span multiple theme values. This method is used quite rarely.
So, I hope that you can see the importance of thematic maps pertaining to the information they convey. Thematic maps are an important tool for getting all kinds of information regarding geographical regions.
Wednesday, May 20, 2009
Wednesday, May 13, 2009
Liquid Wood
Do you know that the plastic handbag that you use is dangerous for our environment? Do you know that the plastic is non-degradable and can result in the killing of various animals which eat them? So, if you are really concerned about your environment, then I would suggest that you start using "Liquid wood" and support the banning of plastics.
Simply stating, "Liquid Wood" is a bio-degradable plastic which is made up of lignin. It is basically derived from wood-pulp based lignin which can be mixed with hemp, flax or wood fibers and other additives for creating a strong, non-toxic alternative to petroleum-based plastics. Liquid plastic is seen as a major breakthrough in dealing with the hazardous implications of plastics (that are increasingly being used today).
How is Liquid Wood made?
During the manufacture of paper, the cellulose is separated by the wood industry into three main components namely-lignin, cellulose and hemicelluloses. Out of these, lignin is not required for paper making. So, it is mixed with fine natural fibers made of wood, hemp or flax and natural additives such as wax. After mixing and heating under high pressure conditions, a plastic granulate is produced which can be melted and injection-molded. As, you can see, this plastic is surely a better alternative to the petroleum based plastic which relies on the oil reserves of the world that will automatically get depleted one day!
The research on the manufacturing of bio-plastic began in 1990's by Norbert Eisenreich's group at the Fraunhofer Institute of Chemical Technology. This team developed "liquid wood" and trademarked it with the name of Arboform. This plastic further got processed by Tecnaro a German company which molded and produced it in pellet form. As compared to the petroleum-based plastics, when Arboform is used, it does not add to the atmospheric level of Carbon dioxide. Hence, the normal carbon cycle does not get disrupted with the use of this plastic.
Moreover, Arboform has great thermal and mechanical properties, when compared to putting wood and plastic together. It is a biodegradable thermoplastic engineering material of better quality and vigor that is going to replace all the technological demands revolving around the use of unhealthy plastic. Although car parts and other durable items made of bio-plastic exist today but this plastic has not been used till yet for household purpose because of the high contents of sulphur present inside it. However, research is going on and soon we can hope to find the use of this plastic in household items.
"Liquid wood" certainly has a bright future and can be seen as a serious attempt taken by scientists to protect our environment! The use of "liquid wood" certainly promises a better and safer tomorrow.
Simply stating, "Liquid Wood" is a bio-degradable plastic which is made up of lignin. It is basically derived from wood-pulp based lignin which can be mixed with hemp, flax or wood fibers and other additives for creating a strong, non-toxic alternative to petroleum-based plastics. Liquid plastic is seen as a major breakthrough in dealing with the hazardous implications of plastics (that are increasingly being used today).
How is Liquid Wood made?
During the manufacture of paper, the cellulose is separated by the wood industry into three main components namely-lignin, cellulose and hemicelluloses. Out of these, lignin is not required for paper making. So, it is mixed with fine natural fibers made of wood, hemp or flax and natural additives such as wax. After mixing and heating under high pressure conditions, a plastic granulate is produced which can be melted and injection-molded. As, you can see, this plastic is surely a better alternative to the petroleum based plastic which relies on the oil reserves of the world that will automatically get depleted one day!
The research on the manufacturing of bio-plastic began in 1990's by Norbert Eisenreich's group at the Fraunhofer Institute of Chemical Technology. This team developed "liquid wood" and trademarked it with the name of Arboform. This plastic further got processed by Tecnaro a German company which molded and produced it in pellet form. As compared to the petroleum-based plastics, when Arboform is used, it does not add to the atmospheric level of Carbon dioxide. Hence, the normal carbon cycle does not get disrupted with the use of this plastic.
Moreover, Arboform has great thermal and mechanical properties, when compared to putting wood and plastic together. It is a biodegradable thermoplastic engineering material of better quality and vigor that is going to replace all the technological demands revolving around the use of unhealthy plastic. Although car parts and other durable items made of bio-plastic exist today but this plastic has not been used till yet for household purpose because of the high contents of sulphur present inside it. However, research is going on and soon we can hope to find the use of this plastic in household items.
"Liquid wood" certainly has a bright future and can be seen as a serious attempt taken by scientists to protect our environment! The use of "liquid wood" certainly promises a better and safer tomorrow.
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