NLSC has carried out the field survey at the intertidal zone areas from Taoyuan to Kaohsiung during 2004 to 2009. All basic topographic products have been transformed from the data style of CAD to GIS in the years of 2007 to 2011 to meet the need of broader uses. More information in detailed can be accessed via the basic map website (http://bmap.gov.tw/bmap/en/index.php).