年分,天然河岸長度(公里)
2001,1764.37
2002,1744.18
2003,1731.71
2004,1697.14
2005,1676.71
2006,1640.69
2007,1603.07
2008,1580.28
2009,1571.57
2010,1501.90
2011,1371.18
2012,1364.20
2013,1385.03
2014,1368.71
2015,1354.38
2016,1343.89
2017,1329.23
2018,1312.47
2019,1300.89
2020,1280.39
2021,1276.60