大连湾60多年来生态环境地质演化

Evolution of Ecoenvironmental Geology in the Past Sixty-odd Years in the Dalian Bay

依据对大连湾60多年来沉积柱的生态环境地质演化研究,发现其污染变化可以分为3个时段:①1933～1974年为洁净时段;②1974～1989年为污染较重时段;③1989～1997年为严重污染时段。若视第一时段的污染度为0,则第二时段的污染度为第一时段的8倍,第三时段的污染度为第一时段的25倍,可见污染度增加是非常迅速和严重的。其中Cd、Pb、As、S、Zn5种元素含量增加最快。1997年大连湾表面沉积物中Cd、Hg、Pb、As的含量分别为自然背景值的81.42倍、6.0倍、7.54倍、3.82倍,表明大连湾污染的严重性。研究发现自1950年以来大连湾生物多样性急剧下降,说明污染度增加已对生命健康造成严重的影响。大连湾的臭水套已成为一个生物多样性异常低下的、超级污染的环境,是一颗巨大的隐性化学定时炸弹。

Based on the study of the ecoenvironmental geological evolution of the sedimentary column since more than 60 years ago in the Dalian Bay, it has been found that the variations of pollution degree can be divided into three phases: A (1933 - 1974) is a clean period, B (1974 - 1989) a relatively contaminating period and C (1989 -1997) a seriously contaminating period. Suppose the pollution degree of period A is zero, the pollution degree of period B is 8 times higher than that of period A, and that of period C is 25 times higher than that of period A. This indicates that the pollution degree has increased tremendously. Five elements, i. e. Cd, Pb, As, S and Zn, have incresed the fastest in content. The concentrations of Cd, Hg, Pb and As in the surface sediments of the Dalian Bay were 81. 42 times (Cd), 6. 0 times (Hg), 7. 54 times (Pb), and 3. 82 times (Zn) higher than the natural background values respectively in 1997. It shows that the pollution in the Dalian Bay is very serious. This study reveals that the biodiversity has decreased rapidly since 1950 in the Dalian Bay, indicating that the increase of pollution degree has greatly affected the life and health of humans.At present, Choushuitao in the Dalian Bay has a super polluted environment with very poor biodiversity, which is considered as a huge hiden chemical time bomb.