A morphological analysis of tidal creek in the Yellow River Delta based on remote sensing

Combing remote sensing images and field observation data, we analyzed the changes of coastal tidal creek morphology from 1976 to 2016 in the Yellow River delta. The results showed that: (1)The area of tidal flat showed a trend of decline, especially areaⅡhas almost demise, which was mostly being transformed into construction land and farmland, etc.(2)The tidal ditchesin the study area were divided into three levels, and the number of tidal ditches of each level did not show obvious regularity. The total number of tidal creeks in three periods was consistent with the variation trend of the number of tidal ditches at all levels. (3) The average length of thetidal creeks decreases successively in turn, the spatial distribution of tidal creeks varies greatly, and the development of tidal creeks is obviously inhibited by intensive human activities.(4) The density of tidal groove increases successively over time, showing the maximum is 0.971 km/km², in 2016. Over all, the average curvature of tidal creeks of all the 5 phases is 1.273, which the developed curvature is relatively small, with the maximum of 1.716, in 2016.The branching rate of tidal groove in 5 phases increases successively and the maximum is 0.363 /km² in 2016. (5) No significant difference of the level of tidal creek oscillation was detected, with showing the swing scopes of 4 periods are 1.13 km, 1.31 km, 0.93 km and 1.19 km, respectively.