历史时期太湖流域西北部的水流流向与湖泊开发——以芙蓉湖为例

Water Flow Dynamics and Lake Reclamation in Northwest Taihu Lake Area in Historical Period:A Case Study of Furong Lake

汉代之前至今,太湖流域西北部常锡澄区水流主流向呈现由南向北的转变,转折的节点在唐宋时期,这是由历史时期海岸线盈缩、潮流动力强弱与太湖流域来水、去水形势等长时段外因变化决定的。受水流动态变化影响,芙蓉湖的变迁可分为唐以前、唐宋、元明及以后三个时期。唐以前芙蓉湖的开垦利用了其主流南向的特点,主要在无锡以东及运河无锡段以南区域进行,这改变了芙蓉湖南缘的原始形态,塑造了芙蓉湖、运河与太湖的界岸。宋代整体水文格局不利于芙蓉湖的开垦,诸次疏浚河道及堰闸体系的修筑事倍功半。元明开始水文格局的转变则是芙蓉湖最终被完全、稳定开垦的根本因素。水流动态不仅影响着芙蓉湖的开发进程与成效,也影响着“五湖”记载等相关史料的书写与塑造。

The flow direction of the mainstream shifted from southwards to northwards in the ChangXi Cheng District,northwest of the Taihu Lake Basin,from preHan Dynasty to today.The turning point was approximately between the Tang and Song Dynasties.This was driven by the longterm external factors such as the advance and retreat of coastlines,the variation of tidal power and the water storage and drainage situations in the Taihu Lake Basin over historical periods.Influenced by the variation of mainstream flow directions,the reclamation process of Furong Lake can be divided into three stages.Before the Tang Dynasty,the reclamation attempts in the Furong Lake Area were mainly conducted in the east of Wuxi and the south of the primitive Grand Canal in Wuxi section to adapt to southward characteristics of the mainstream flow in this time.Such projects changed the original form of the south edge of the Furong lake,and shaped the boundaryconbank between the Furong lake,primitive canal and Taihu Lake.In midTang Dynasty,the south edge of the the Furong Lake retreated by nine li(traditional Chinese length units,one li equals 500 meters approximately)north of the Wuxi section of the Grand Canal.The overall hydrological pattern in the Song Dynasty made it hard for the longlasting success of reclamations of the Furong lake.All the attempts in this time such as the dredging of river channels and the construction of weir and gate system were soon proved unsustainable.The variation of hydrological patterns in not only the ChangXiCheng District but also the entire Taihu Lake Basin since the Yuan and Ming Dynasties was the fundamental factor for the complete and final reclamation success of the Furong lake.The dynamic variation of water flows was not only affected the reclamation process of the Furong Lake,but also recorded in the writings of relevant historical material.