Study On The Erosion And Its Countermeasures Of The Modern Yellow River Delta Coast

The Modern Yellow River Delta is located from Taoer River to Zhi- maigou on the southwest side of Bohai Sea and a new-born area with a silting-up rate of 20~25km2/a since its sea-running towards Bohai Sea in 1855. Because of its special character, the terminal channel of the Yellow River changed frequently, which brought this area both large-scale silting-up and erosion. But before 1990s the main evolution trend of the Yellow River Delta was silting-up and it was in the second half of 1990s that the area decreased by 2.6km2, then the whole delta began to be erosion. The time-increasing coastal erosion has now seriously harm both the evolution and economic environment of the Yellow River Delta, from which the Shengli Oil Field and National Ecological Modern Region has suffered a lot.Based on several relevant projects, this paper systemically analyzed the influential element of the costal erosion in Yellow River Delta and found that the sedimentological dynamics character, changes of the river courses and water-sand contents, and relative sea-level rise are the main reason for the costal erosion. According to the comprehensive analysis of the above elements, there is a non-reverse trend of erosion in the Yellow River Delta coast. As for the countermeasures, firstly the water and sand sources should be reasonably allocated and managed. Meanwhile, considering coastal erosion's regional and imbalance characters, special measurements should be taken according the regional characters of Yellow River Delta. High-standard coastal protection structures should be built near the Paleo-Yellow River mouth area and breakwaters should be constructed where there is a high concentration of oil wells. Whereas in the newly Yellow River mouth area, the main purpose of the measurements should be enhance the siltation to maintain the beach. When it comes to the area between the above two, breakwaters should be reinforced as well as protected.