In order to standardize and unify the production and application of digital fundamental map of water resources, Ministry of Water Resources approved and issued the Water Industry Standard "Standard of the digital fundamental map products in the water resources sector " (SL/Z 351-2006) on October 23, 2006, and it will be put into effect on December 1, 2006. This standard regulates the classification, the composition and content digital fundamental maps of water resources, and it is also applicable to the development and production of various types of digital maps.