古代长江中下游平原筑堤围垸与塘浦圩田对地理环境的影响

未开发前的长江江汉平原和江南三角洲地理环境十分相似,同属低平的冲积平原,故筑堤御洪成为开垦的必要条件。江汉平原采用了筑堤围垸的开垦方式,使地表起伏增大,荆江、汉水河床淤高,沿岸河漫滩、穴口、水系与湖泊受到淤积,使泄洪和调节径流能力降低,破坏了地理环境,造成了严重的洪、涝、旱等灾害。江南三角州采取了塘浦圩田的开垦方式,不改变地表起伏,水系、湖泊都能得以长期保存,对某些不利的地理环境加以合理的改造,历史上洪、涝、旱等灾害显著减少。历史经验表明,对一个地区的建设,应根据其地理环境的特点,采取合理的开发方式。江南三角洲的塘浦圩田的开垦方式,是一个可供借鉴的范例。

INFLUENCE TO GEOGRAPHIC ENVIRONMENTOF LOW-LYING FIELDS SURROUNDED WITHDYKES AND TANG PU CHANNEL OVER MIDDLEAND LOWER REACHES OF THE YANGTZERIVER IN ANCIENT TIMES

Geographic environment of Jianghan Plain in the middle reach and South Delta in the lower reach of the Yangtze River was quite similar before they had been developed. But the two areas are remarkably different because of different ways of reclamation used over the history.Jianghan Plain adopted the way of surrounding low-lying fields with dykes. It made landform standing in relief with water system and lakes deposited. And it also reduced flood discharge capability of regulating run off. All results in destroying the geographic environment and bringing about flood, water logging and drought. While South Delta adopted low-lying fields surrounded with dykes and Tang Pu channel. It did not change relief of the landform, and thus no deposit for water systems, Tang Pu channel and lakes. So it has been kept that way over long period of time, and has conserved an advantageous geographic environment. Over the history of flood and water logging, the South Delta has had much less disasters than the Jianghan Plain. History has taught us how to do things according to the rules of a geographic environment. The proper way of developing South Delta of the Yangtze River has been adopted so successfully that it may be used as a good reference.