The changing pattern of the Lower Yellow River （LYR） obtained from the traditional studies, which mainly did literal analysis based on historical documents related to the LYR are too macroscopic and absent of intuit...The changing pattern of the Lower Yellow River （LYR） obtained from the traditional studies, which mainly did literal analysis based on historical documents related to the LYR are too macroscopic and absent of intuitiveness. This paper integrates all the records in historical documents related to course shift, flood and overflow of the last 3000 years and stores them in a GIS database. Then, all the data will be visualized in the form of map, which is helpful to show and understand the rules those events conform more intuitively and accurately. Taking these data as foundation, this study summarizes characteristics of the LYR＇s courses and influence scope, and classifies them both into three types; divides the flow directions of the LYR＇s courses into two periods, and proposes its changing pattern; concludes the character- istic of diversion points of courses shift events; calculates the velocity of courses shifts, gra- dient and sinuosity, and analyzes their changing patterns. Finally, this study classifies factors that may influence the occurrence of a course shift into two types： the internal factors, such as sediment rate, gradient and sinuosity of the river, and the external factors, such as precipita- tion and human activities.展开更多
基金Project supported by the Ministry of Science and Technology of China, No.2009BAH50B01No.2008BAK50B05
文摘The changing pattern of the Lower Yellow River （LYR） obtained from the traditional studies, which mainly did literal analysis based on historical documents related to the LYR are too macroscopic and absent of intuitiveness. This paper integrates all the records in historical documents related to course shift, flood and overflow of the last 3000 years and stores them in a GIS database. Then, all the data will be visualized in the form of map, which is helpful to show and understand the rules those events conform more intuitively and accurately. Taking these data as foundation, this study summarizes characteristics of the LYR＇s courses and influence scope, and classifies them both into three types; divides the flow directions of the LYR＇s courses into two periods, and proposes its changing pattern; concludes the character- istic of diversion points of courses shift events; calculates the velocity of courses shifts, gra- dient and sinuosity, and analyzes their changing patterns. Finally, this study classifies factors that may influence the occurrence of a course shift into two types： the internal factors, such as sediment rate, gradient and sinuosity of the river, and the external factors, such as precipita- tion and human activities.
