网状河流和分汊河流的河型归属讨论

河流的河道平面形态分类有多种方案 ,其中Rust的分类因为分出了网状河流而得到沉积学家的更多关注。中国地貌学界和水利学界则更关注钱宁的分类 ,其中包括分汊河流。目前 ,许多研究人员把网状河流和分汊河流当作同一类型的河流。文中从河型的定义、河道平面形态、地下沉积物特征、水动力、新河道形成机理和发育的地貌部位等方面对分汊河流和网状河流进行对比 ,根据对比结果认为它们是不同的河型。为了便于沉积学家、水利学家以及地貌学家之间相互交流各自有关河流的研究成果 ,需要提出一个更符合实际的冲积河流分类方案。

DISCUSSION ON CHANNEL PATTERNS OF ANASTOMOSING AND ANABRANCHED RIVERS

According to channel planforms in the world,there are many classification schemes of fluvial rivers in which the scheme proposed by Rust (1978) received extensive attention from many sedimentologists because one of its river types is classied as the anastomosing. While hydrologists and geomorphologists pay more attention to the classification scheme derived by Qian Ning (1987) because one of its river types is noticed as the anabranched. The two classification schemes were considered actually as one type by many researchers. Whether the anastomosing and the anabranched rivers belong to the same type of channel patterns is still questionable. In this paper some characteristics, such as definitions, channel planforms, interchannel subdeposits, hydraulics, formation mechanisms of a new channel and geomorphological location, etc. of the anastomosing and the anabranched rivers are compared. It is concluded that the type of the anastomosing river is different from that of the anabranched one. So for the sake of convenience to exchange the achievements in river research among sedimentologists, hydrologists and geomorphologists, a new classification scheme of fluvial rivers is possibly required.