Feature – Oil and Water: Mapping the South China Sea

Oil and Water: Mapping the South China Sea

The turmoil in the South China Sea, one of the most strategic and debated bodies of water in the world, presents a unique challenge when it comes to mapping. The interaction of different layers provides interesting, if not clear, correlations. The same question is often asked: who owns the ocean? At least, who owns this part of the ocean? What can we learn from this overlapping and sometimes conflicting data?

UNCLOS (United Nations Convention on the Law Of the Sea) dictates a nation’s Exclusive Economic Zone (EEZ) extends 200 nautical miles from its coastline, and gives territorial rights to the owner-nation for fishing, mining, and extraction of any other natural resources inside that imaginary line.

Although it’s named for just one of the bordering countries, the South China Sea plays host to a dispute involving China (including Taiwan), Vietnam, Malaysia, the Philippines, and Brunei. They’ve all laid claim to varying numbers of small, historically uninhabited islands scattered throughout, muddying the EEZ. The three primary island chains in question are known as the Paracels, the Spratlys, and the Scarborough Shoal.

Overlapping EEZs

The challenge of mapping? Each nation is constantly building and expanding the islands in an attempt to validate their EEZ claims. Some nations have no presence on the islands they claim, while others do. Because of the proximity of the nations, the EEZ’s overlap naturally anyway.
Therein lies the first issue. While EEZs allow countries to utilize resources in their zone, they also must allow innocent passage through the EEZ. However, because of the history of the region, the overlapping EEZs are only the first of the problems.

Photo Credit: David Rosenberg

The Nine (maybe ten) Dash Line

The Nine Dash Line map, originally released in 1947 by the Chinese nationalist government, predates the UNCLOS, and originally had eleven lines outlining China’s claims in the South China sea. It was adopted in 1949, but later two lines were dropped to allow Vietnam and China to settle their disputes in the Gulf of Tonkin.

But in 2014, Beijing released a new map with a line east of Taiwan. China has not yet clarified if they are just claiming the land (islands) inside this line, or are also claiming maritime rights. This claim is unrelated to any EEZ claims.

Air Defense Identification Zones

Adding to the complication in mapping is the Air Defense Identification Zones (ADIZ). These are established by each country and is airspace not necessarily just within the border of the country where civilian aircraft must identify themselves, or face possible interception.
There are at least two areas in the South China sea where ADIZ’s overlap: China, South Korea, and Japan all overlap at one point, and Taiwan and China overlap at another. Since these are arbitrary and not governed by international law, they offer no sovereign rights, but do offer challenges to the pilots of any civilian aircraft who choose to fly in the area.

Besides the disputes over air, land, and sea, the area carries much of the world’s trade by ship, and especially strategic is the Strait of Malacca, which links the Pacific and Indian Oceans. Twenty five percent of all traded goods that travel by sea pass through this straight, as does twenty five percent of the oil that travels by sea.

In addition, the South China Sea is in itself filled with natural resources including natural gas and oil. The extent of these resources is not yet known, as disputes have prevented full exploration. So what does this region teach us about mapping and GIS?

Photo Credit: Economist

The Importance of Current and Relevant Data

The data we enter to create layers must meet three criteria: it must be accurate, up to date, and relevant. This can be challenges in cases like this, where both China and Vietnam are building and changing the structure of islands to change their EEZ. Islands change hands, and are either occupied or unoccupied frequently.

The latest geographic information, along with political maneuverings and decisions can affect the way the map looks.

The Importance of Historical Maps
The Nine Dash line predates the current EEZ disputes. Often when mapping data, GIS technicians need to keep in mind not only the current data, but historical data as well. Often we use the past to inform the present, and the addition of historical mapping and data layers is invaluable.

Photo Credit: Wikipedia

The Importance of Understanding Map Purpose

Knowing why a map is being created helps determine what information should or should not be included, and and even how it should be arranged.

A map to illustrate the political or military situation in the South China Sea would contain or prioritize different elements than one designed to show the viability of extracting natural resources in the area. An aviation map for private aircraft would contain some of the same elements, while others would not be nearly as critical.

In the era when even the government is embracing big data and cloud computing, it is often easier to include more rather than less in a map, but with certain applications keeping in mind the device that will actually be used to transport and utilize the map and how rapidly it must be accessed determines how much data should be included.

A volatile area like the South China sea where the map is constantly changing serves to remind us of how important the fundamentals of creating GIS products truly are. Obtaining relevant and historical data, and understanding how the products we create will actually be used makes them more useful and informative. Of course, that’s the purpose of creating them in the first place.



Troy Lambert is a freelance writer, editor, and non-profit consultant by day, and a suspense thriller author by night. He learned about the power of GIS while working as a researcher at a museum, and is always looking for ways to apply this technology and big data in new and innovative ways. Troy is an avid cyclist, skier, and hiker. He lives, works, and plays in Boise, Idaho. His work can be found at troylambertwrites.com, and you can connect with him on Twitter @tlambertwrites.

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