Raised-relief map

Hand-made raised-relief map of the High Tatras in scale 1: 50 000

A raised-relief map or terrain model is a three-dimensional representation, usually of terrain, materialized as a physical artifact. When representing terrain, the vertical dimension is usually exaggerated by a factor between five and ten; this facilitates the visual recognition of terrain features.

History

If the account of Sima Qian (c. 145–86 BCE) in his Records of the Grand Historian is proven correct upon the unearthing of Qin Shi Huang's tomb, the raised-relief map has existed since the Qin dynasty (221–206 BCE) of China. Joseph Needham suggests that certain pottery vessels of the Han dynasty (202 BCE – 220 CE) showing artificial mountains as lid decorations may have influenced the raised-relief map.[1]

The Han dynasty general Ma Yuan made a raised-relief map of valleys and mountains in a rice-constructed model of 32 CE.[2] Such rice models were expounded on by the Tang dynasty (618–907) author Jiang Fang in his Essay on the Art of Constructing Mountains with Rice (c. 845). A raised-relief map made of wood representing all the provinces of the empire and put together like a giant 0.93 m2 (10 ft2) jigsaw puzzle was invented by Xie Zhuang (421–466) during the Liu Song dynasty (420–479).

Shen Kuo (1031-1095) created a raised-relief map using sawdust, wood, beeswax, and wheat paste.[3][4] His wooden model pleased Emperor Shenzong of Song, who later ordered that all the prefects administering the frontier regions should prepare similar wooden maps which could be sent to the capital and stored in an archive.[5]

In 1130, Huang Shang made a wooden raised-relief map which later caught the attention of the Neo-Confucian philosopher Zhu Xi, who tried to acquire it but instead made his own map out of sticky clay and wood.[5] The map, made of eight pieces of wood connected by hinges, could be folded up and carried around by one person.[5]

Later, Ibn Battuta (1304–1377) described a raised-relief map while visiting Gibraltar[6]

In his 1665 paper for the Philosophical Transactions of the Royal Society, John Evelyn (1620–1706) believed that wax models imitating nature and bas relief maps were something entirely new from France.[7] Some later scholars attributed the first raised-relief map to one Paul Dox, who represented the area of Kufstein in his raised-relief map of 1510.[7]

Construction

Starting with a topographic map, one can cut out successive layers from some sheet material, with edges following the contour lines on the map. These may be assembled in a stack to obtain a rough approximation of the terrain. This method is commonly used as the base for architectural models, and is usually done without vertical exaggeration. For models of landforms, the stack can then be smoothed by filling with some material. This model may be used directly, or for greater durability a mold may be made from it. This mold may then be used to produce a plaster model.

A combination of computer numerical control (CNC) machining a master model, and vacuum forming SAM copies from this, can be been used to rapidly mass-produce raised-relief maps.

Another method which is becoming more widespread is the use of 3D printing. With the rapid development of this technology its use is becoming increasingly economic.

Non-terrain applications

For appropriate mathematical functions and especially for certain types of statistics displays, a similar model may be constructed as an aid to understanding a function or as an aid to studying the statistical data.

Notable examples

The Great Polish Map of Scotland is claimed to be the largest terrain relief model, constructed out of brick and concrete in the grounds of a hotel near Peebles, Scotland. It measures 50 by 40 metres (160 ft × 130 ft).[8]

However, a site in Ningxia province, China was spotted in 2006 using satellite imagery. It measured 900 by 700 metres (3,000 ft × 2,300 ft), had a 3-kilometre (1.9 mi) perimeter and appeared to be a large scale relief model of Aksai Chin, a disputed territory between China and India.[9]

See also

References

  1. ↑ Needham (1986), Volume 3, 580–581.
  2. ↑ Crespigny (2007), 659.
  3. ↑ Sivin (1995), III, 22.
  4. ↑ Needham (1986), Volume 3, 579–580.
  5. 1 2 3 Needham (1986), Volume 3, 580.
  6. ↑ Needham (1986), Volume 3, 579
  7. 1 2 Needham (1986), Volume 3, 579.
  8. ↑ Bruce Gittings; Royal Scottish Geographical Society. "Polish Map of Scotland". Gazetteer for Scotland. The Editors of The Gazetteer for Scotland. Retrieved 2012-07-11.
  9. ↑ "Chinese X-file not so mysterious after all". The Age (Melbourne). July 23, 2006. Retrieved 2012-07-26.
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