云南省大理州的云龙和南涧县城内均有河流穿城而过,穿过云龙县城的狮尾河因泥沙淤积,曾于1993年引发城区洪涝灾害。为此云龙县治理了县城内的狮尾河;南涧县为满足县城发展扩建的需要,对流经县城的南涧河县城段也进行了改造治理。两县建造“V”形槽河(沟)底的主观愿望是预防洪涝灾害的 The rivers in Yunlong and Nanjian counties in Dali Prefecture of Yunnan Province both run through the city, and the Liwei River crossing Yunlong County caused siltation in the city. In 1993, it caused flooding in urban areas. To this end Yunlong County governance within the county’s Lion River; Nanjian County in order to meet the needs of the development and expansion of the county, Nanjianhe County through the county section has also been transformed governance. The subjective desire of the two counties to build a “V” -shaped trough river (bottom) is to prevent floods