Abstract:

Based on the China topographic maps compiled by US Army Map Service in 1954, maps made by Japanese Military Headquarters from 1930 to 1934, hydrology chronicles of Guangdong and local records of every counties in research area, by reconstructing river network models of research area in the 1930s and with high precision recovering the plain river network and river systems during the last phase of traditional agriculture, its max channel storage capacity was to be calculated and preliminary analysis about regional characteristics could be obtained. Results indicate that: 1)The max storage capacity of the Pearl River Delta (excluding the main river channel) in the 1930s was ranging from 6.78×10⁸ m³ to 20.75×10⁸ m³, with an extremum being 20.75×10⁸ m³ and average value being 13.38×10⁴ m³/km². Accounting for 33.5%~49.1% of the total channel storage capacity, the first grade watercourse had a far greater impact on flood capacity of the entire river and scheduling ability of water resources. Different from the present stage, the channel storage capacity of the Pearl River Delta at the last phase of traditional agricultural era (the 1930s) was positively correlated with drainage density. And it is obvious that the size of the channel storage capacity was affected by drainage density. 2) The formation of the Pearl River Delta in the 1930s had a close relationship with the agricultural development in traditional period. The river water system at that time was an outcome of natural development and diked field in traditional era. Building bunds, digging and dredging rivers and other ways of field development objectively promote the expansion of the river and increase in the max channel storage capacity.

Key words: river network structure, max channel storage capacity, the Pearl River Delta