太湖沉积速率分布演化及其淤积程度健康评价

DISTRIBUTION OF DEPOSITION RATE OF LAKE TAIHU AND ITS HEALTH ASSESSMENT

分阶段(1963～1986,1986～2002)分析了太湖各湖区沉积速率空间分布,发现各湖区沉积速率均有不同程度的增加,以东太湖最为显著,从2.9mm/a增加至12.4mm/a。同一沉积速率对不同水深的湖泊有不同的意义,因此为了对太湖各湖区淤积程度进行健康评价,提出相对沉积速率的概念,即沉积速率与湖泊平均水深的比值,并将其作为评价湖泊淤积程度健康与否的指标。健康评价标准根据国内主要湖泊的相对沉积速率确定,即最大相对沉积速率健康得分为0,相对沉积速率为0,健康得分为100,归一化求得太湖各湖区淤积程度健康得分。结果表明,贡湖、湖心区处于健康状态,东太湖为不健康,其他湖区为亚健康,全湖有从亚健康向不健康发展的趋势。

The deposition rate of different zones of Lake Taihu was evaluated at two stages（1963~1983,1983~2002）.The results showed that the deposition rates increased at different degrees in space,and the East Lake was the most significant in Lake Taihu.It increased from 2.9 mm/a to 12.4 mm/a.Since deposition rate has different meaning to different depth of shallow lake,the relative deposition rate（RDR）was proposed to assess the health states of Lake Taihu in deposition.RDR is the ratio of deposition rate to depth.The health index was determined by the deposition situation of the principal domestic lakes.The lake of maximum RDR was defined as health score of 0,and the lake of RDR being 0 was defined as health score of 100,thus the health index of Lake Taihu could be calculated by linear interpolate.The RDR shows that Gonghu bay and Centre lake are in health states,East lake is the only unhealth zone,and the others are subhealth.The whole lake has a deteriorate trend from sub-health to unhealth.