珠江河口特征认知的发展

Cognitive development of characteristics of the Zhujiang River Estuary

人们对珠江河口的认知发生过几次飞跃。第一次认知飞跃,柯维廉(W.Olivecrona)1915年首次提出了珠江三角洲的概念;第二次认知飞跃,吴尚时1937年证明海水曾深入广州形成珠江河口湾并发育三角洲,1941和1947年先后著文肯定了珠江三角洲的存在,并确定了其主体范围;第三次认知飞跃,曾昭璇1980年提出了冲缺三角洲的概念,1997年提出了串珠状冲缺三角洲发育模式,揭示了珠江三角洲发展的时间与空间位置;第四次认知飞跃,赵焕庭1982年揭示了珠江三角洲叠置晚更新世晚期老三角洲与全新世中期现代三角洲,新资料显示还存在晚更新世中期三角洲;第五次认知飞跃,赵焕庭等于1973-1982年间运用西蒙斯优势流概念和河口盐水楔理论研究了口门和河口湾滩槽地形的发育演变;第六次认知飞跃,吴超羽等于2006年创造性应用自己研发的长周期机理模型和沉积学、地貌动力学等多学科互证,量化再现了珠江三角洲6~2.5ka BP"镶嵌式"演变过程。

Foreign scientists firstly began to examine the delta of the estury of Zhujiang River along with the invasion of powers and the input of theory and technique of modern natural science into China.Then local scientists mastered and developed the associated knowledge and started the research of the natural entity.There are 6 leaps in the cognition of the Zhujiang River Estury.In 1915,W.Olivercrona wrote paper to call it＂Guangzhou Delta＂after field investigation and first proposed the concept of＂Zhujiang River Delta＂,which is looked as the first leap.The second leap is made by Wu Shangshi,who discovered the geomorphology of sets of ancient sea cliff-sea cave-wave erosion platform and ancient sandbank-dried lagoon in the suburb of Guangzhou in 1937.In the academic debate of the presence of the Zhujiang River Delta,he supported the opinion that the seawater had been transgressioned into ancient estuary and developed delta.He wrote papers in 1941 and in 1947 to affirm the existence of the Zhujiang River Delta and determined its range.The third leap is created by Zeng Zhaoxuan,who proposed the development pattern of beading gap-cut deltas in 1980.He explained the special-time location of the the Zhujiang River Delta according to his creative study of historical morphology.The forth leap is in 1982,when Zhao Huanting revealed that the Zhujiang River Delta overlaid on old delta formed in the later period of later Pleistocene and modern delta forming in the middle Holocene,on the base of Wu Wenzhong＇s discovery about weathered granophyric ancient estuarine facies clay layer buried in the Zhujiang River Delta.New datum displayed the older delta formed in the middle period of later Pleistocene.The fifth leap is also marked by Zhao Huanting.In 1973-1982,he found the Zhujiang River Estury zone is distinct because river network in delta and residual estuary co-existed.He was one of the first scientists to study riverbed evolution of Zhujiang distributaries in the Shiziyang Distributary,estuary evolution in the Lingdingyang Estuary,and the distributaries mouth evolution in Modaomen distributary mouth.He used Simmons＇ s concept of dominant flows and theory of estuary salt water wedge to study the morphological development and evolution of the distributary mouth and estuary.In 1990 he preliminarily summarized the evolution process of the Zhujiang River Estuary.The sixth leap is from Wu Chaoyu,who quantitatively reappeared the mosaic evolutionary process of the Zhujiang River Delta from 6 ka BP to 2.5 ka BP,according to the mutual confirmation of sedimentology,geomorphydynamics and his long-period mechanism model in 2006.