EVOLUTION OF THE SHELL RIDGE ISLANDS IN THE NORTHERN YELLOW RIVER DELTA

This study presents an analysis of the evolution of shell ridge islands on the front margin of the abandoned delta lobe and of the storm shell islands on the head of the tidal river gulf or on the outer side of the tidal channel in northern Yellow River delta. Using comparisons of topographic maps, Landsat images and other survey results during different times as well as new survey data, the changes of quantity, area and evolution characteristics about the two kinds of shell ridge islands have been studied. Since 1950s, the shell ridge islands in the northern Yellow River delta have changed a lot because of natural and human activities, while they have different evolution results from different formation courses.Human activities have been considered as the main restrictive factor in the recent evolution development of the shell ridge islands. At present, the shell ridge islands are changing dynamically,especially the natural evolvement course of the storm shell islands on the head of the tidal river gulf or on the outer side of the tidal channel is almost ended and turning into a new estate.