太湖水系结构特点及其功能的变化

THE STRUCTURE CHARACTERISTICS AND THE FUNCTIONAL VARIATION OF THE RIVER SYSTEMS IN TAIHU LAKE CATCHMENT

太湖水系上游为树枝状排列的河流，下游为扇形排水系统，全区江河湖海相贯通，受海潮和江流的作用,下游水系多变，防洪抗灾能力脆弱．近年来，虽经治理，该水系仍出现了“中雨大灾”，水资源不足及水质污染突出等一系列功能性的变化．究其原因．主要是在自然及人为因素的影响下，出现了许多人和自然、现代和将来、经济和环境诸方面的新问题和新矛盾．有待进一步解决．

In the upper reaches of Taihu Lake Basin, the river courses assume branches in shapeand fan shaped drainage system distribute in the lower reaches. Throughout the drainge area river, lakes and link up one another. Affected by sea tide and the river flow. the hydrographic net of lower river has become changeable and the capacity of preventing flood and fighting calamities weak. In recent years such functional variations have happened as 'moderate rain with heavy calamities',the inadequate water resources and the serious water pollution,etc. The main cause is that with the effect of natural and artifical factors. many new problems and controdictions in the human being and nature, present and future.economy and environment are brought forward and need to be solved further.