Evolution Of Diaokou Channel Lobe In Yellow River Delta

The Yellow River Delta is the seat of Shengli Oilfield and Dongying City.The strengthend study of the evolution of the ancient chanel and lobe in Yellow River Delta helps oilfield development, industial and agricultural production, and the prevention and contol of geological disasters. In this paper, many years of remote sensing, bathymetric data and other information, through the analysis of the migration from Shenxiangou Chanel to Diaokou Chanel in1964by an artificial break-through, abandoning the Diaokou Chanel in1976by diverting to Qignshuigou Chanel, include the evolution of the present Diaokou lobe shoreline, chanel,tidal creek and submerged delta. Then carry out comrehensive study of the evolution of the Diaokou Lobe in the Yellow River Delta and perfect the knowlegde of the evolution of delta lobes.Through remote sensing image false color composite images, interpretation extraction28years in the ancient river channel, tidal creek and low tide line.since the low tide line is the dividing line of the onshore delta and subaqueous delta, we use the low tide line as the Diaokou Lobe shoreline when doing statistical analysis.There were5stages in the Diaokou Lobe evolution due to study of the distance and area of shorelines:the flood season of1964is the straightening stage;1964-1976, the rapid depositing stage;1976-1987, rapid withdrawal erosion;1987-2011, the relatively slow retrogradation stage. During the final stage, the shoreline could move slightly back and forth in each year, but the overall trend is backward erosion.The Diaokou chanel evolution was divided into five stages from1964to1976: flood season in1964is the overland flows Gulf filling stage, there were different channel morphology, scattered and varied swale; rivers converged in1976, in which the number of river decreased and converged to a few major shares relative to the year of1964;1966-1972, a single straight stage,in which all scattered small river courses and integrate to a main channel;1972-1976,crevasse bifurcation phase, branch burst at the curve of the main chanel due to sediment deposition; abandoned river stage in 1976, in which artificial diversions of water and sediment supply stopped and then tidal creek developed.According to the measured water depth data for many years, the Diaokou lobes subaqueous delta volume to calculate average water depth and sediment and evolution were analyzed, and the evolution of underwater delta was divided into five stages:1964-1976, the line rapid accumulation phase, in which time water phase of the underwater delta depth quickly becomes shallow, slope changed, and a massive underwater delta deposited;1976-1980was the abandoned early rapid flushing stage, water depth deepening faster, sloping got slightly changed, and subaqueous delta eroded rate became faster;1980-1989was a slow erosion stage, the subaqueous delta eroded rate became slower;1989-1999, relatively stable stage, the amount of scouring and silting in sediment was basically equal;1999-2009, during this stage the erosion continous, the erosion velocity increased compares to the last stage.