|
This paper for many years remote sensing image, depth data, analysis and research Qingshuigou Channel and lobe onshore delta and subaqueous delta evolution, and thus comprehensive study of the evolution of the Yellow River Delta lobes, Qingshuigou, so as to improve the Delta and understanding of the evolution of the lobes, and the next step for Qingshuigou flow path direction of governance, Shengli Oilfield and the further development of the Yellow River Delta to provide the necessary reference. Since 1855, the Yellow Tail 10 diversions, diverted Qingshuigou in 1976 and then in 1996 the Qing 8 Branch, formed the current Qingshuigou flow path. In this paper, visual interpretation from remote sensing image MSS754, TM432 false color composite image, extraction of 21 years (22 times) Qingshuigou main river, the high tide line and low tide line. Runoff and sediment in the river pattern, under the control of the river length and human main river Qingshuigou Channel 1976-2009 years of evolution can be divided into six periods: 1976-1981 estuary filling stage; 1981-1985 single normalized natural state shares stage; 1985-1991, artificial state under a single straight stage; the 1991-1996 Qing 8 manual intervention before branching out bay swing phase; 1996-2004, manual control under a single straight stage; 2004-2009 labor under the control of a bay of the swing phase. Since the boundary of the onshore delta and subaqueous delta for the low-water line, so the use of the low-water line statistical analysis for lobes, Qingshuigou, shoreline can be obtained: Qingshuigou lobes shoreline is generally gradual growth trend, which from 1976 - 1992 is an extension of a rapid period of slight decline in 1993, they began to rise, undulating subsequently within a narrow range. Lobes shoreline can be seen after several cycles, generally a Branch of the length of the coastline due to rapid siltation of estuary increase next year due to the entrance unstable, runoff and sediment supply is not adequate erosion leading to decrease in length of coastline. The evolution of land-based Delta Qingshuigou lobes, made by calculating the area of ??land and erosion net epeirogenic area, and net epeirogenic rate per million tons of sediment created land area and comprehensive analysis, can be divided into four stages :1976-1992; 1992-1996; 1996-2004; 2004-2009. Each stage roughly Asymmetric parabola opening up, each stage is due to the river branching swing start created land area, and sediment epeirogenic rate highest average annual late to extend the supply of sediment as the river and stability The entrance is partially sufficient, and other parts of the Delta due to a lack of supply of sediment and lead to erosion, resulting in the created land area, and sediment epeirogenic rate reduced. Compared to the four stages of decline. Measured depth data from 1976-2005, Surfer kriging interpolation of bathymetric data collected in the Yellow River Delta, and then combined with known Laizhou Bay, Yellow Sea zero the high and low tide proportional relationship between high and low tide lines have been drawn over the years, plotted Yellow zero noodle. Bathymetric data and bathymetric data of the study area above the zero noodle all zeros. Through the use of multi-depth information, the use of indoor processing software on the Yellow River lobes, Qingshuigou, subaqueous delta and scour the calculation (sediment dry bulk density be approximated 1.1t/m3), the evolution of subaqueous delta of the 1976-2005 period of the study area process analysis, mapping the study area subaqueous delta evolution stage is divided into: 1976-1980 multi-the siltation center stage; the 1980-1991 single stable siltation stage; 1991-1996 slow deposition stage; since 1996, siltation, erosion synchronization phase, The subaqueous delta a pile in the the new estuaries accumulation center and the erosion of the old mouth of center. By flow path Qingshuigou, Qingshuigou lobes land-based Delta shoreline erosion area and the evolution of the subaqueous delta analysis, together will the lobes Qingshuigou divided into four stages: (1) 1976 to 1980 phase. Yellow River early Qingshuigou, scattered water, multi-strand into the sea, no stable flow path formed subaqueous delta form of strip, and the multiple siltation Center; ② from 1980 to 1991 for the second stage. Distributary channel is basically stable, form a single into the sea road, river extends, Qingshuigou flow path is more steady advance of the main river, the trend of the coast and the Coriolis force, continue southeast to offset. This period subaqueous delta formed by the accumulation of sand body morphology irregular oval, the long axis parallel to the shoreline; ③ 1991 to 1996, the Qing branching for the third stage, lobe developmental enter the late, epeirogenic rate slowed , the form is more stable. ④ 1996 Yellow clear since the 8 Branch, spit extending back down the river several times swing, new subaqueous delta estuary pile and the old mouth of underwater erosion body showed oval. Has an important influence on the evolution of the lobes: estuary incoming water and sediment, human intervention and control, the trend wave. Runoff and sediment amount of regression analysis.
|