The stability evaluation of lagoon-barrier coastline, Luanhe delta

Luanhe delta has important values in the field of teaching and scientific researches as the most special feature of lagoon-barrier coastline, whose coastline always stays in the state of dynamic changes with the human influence.For calculating the axial length change, annual mean change rate and stability index of coastline for lagoon-barrier in recent years, furthermore, analyzing the stability of sandbar coastline, we extract coastline datum from remote sensing images of 1987, 2000 and 2014.This research reveals that the coastline of lagoon-barrier in Luanhe delta mainly erodes toward land and its maximum axial length is nearly 400 m, whose erosion rate nearly reaches 30 m/a.The ratio of erosion degree from lightly to severe can reach 87%, the stability index of islands that less than 0.4 reaches 74%.After that, more researches have been carried out and indicate that reservoirs construction in the middle and upper reaches of the Luanhe reduce terrestrial sediment supply, which is the main reason that for these changes.Besides, constructions of ports and culture ponds also weaken coastline stability.