China’s Geo-Information Survey

Yuqiao Reservoir, east of Beijing, China from Landsat 8 acquired March 2017. Data courtesy of NASA/USGS,.

The first national geo-information study of China was released last week at a State Council Information Office press briefing.

The study, also referred to as the national census of geographic conditions, was originally announced in March 2013. Over the last three years 50,000 professionals have been involved in collecting a variety of data about China and it’s reported that they have achieved a 92% coverage of the country, generating around 770 terabytes of data in the process.

Data has been collected on natural resources, such as land features, vegetation, water and deserts; together with urban resources such as transport infrastructure, towns and neighbourhoods. This information was gathered, and verified, through remote sensing satellites, drones, aerial photography, 3D laser scanning and in-situ data. It’s reported that the accuracy is 99.7% with a 1 m resolution.

China is one of the largest countries in the world by land mass, at approximately 9.6 m square kilometres. Therefore, simply completing such a study with the accuracy and resolution reported is highly impressive.

It may take years to fully appreciate the variety, size and usefulness of this new dataset. However, a number of interesting high level statistics have already been released by the Chinese Ministry of Land and Resources including:

  • 23.2% of China’s land is above 3,500 m altitude, and 43.4% is below 1,000 m altitude.
  • 7.57 million sq km of the country has vegetation cover, with 21.1% being cultivated lands and the remainder grasslands and forests.
  • 1.3 million sq km of land is desert and bare lands, whilst rivers cover 6.55 million sq km.
  • 153,000 sq km of land has buildings on it.
  • 116,500 sq km of railway track and there is 2 million sq km of roads.

According to Kurex Mexsut, deputy head of the National Administration of Surveying, Mapping and Geoinformation, the Chinese Government will be looking to establish a data sharing mechanism and information services platform for this dataset, together with a variety of data products. It is hoped that public departments and companies will be able to use this to help improve the delivery of public services.

Although not from the survey, the image at the top is of the Yuqiao Reservoir, situated just to the east of Beijing. It has a surface area of 119 sq km, with an average depth of 14 metres.

Not only is this a comprehensive geo-information dataset for a single country, but there is also huge potential for further information to be derived from this dataset. We’ll be watching with interest to see how the data is used and the impact it has.

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