| 摘要: |
| 通过地质调查, 钻孔样品分析及历史资料对比, 得出:1.巢湖位于在中新生代形成的巢湖断陷盆地南部, 形成于更新世发育的河谷平原上, 由于全新世受气候及相应海平面变化和长江河道演变等三者共同影响而积水成湖。成湖历史大约2000年左右, 属河成型浅水湖。2.湖底沉积物平均中值粒径5-6ф, 并形成有三角洲沉积, 开阔湖沉积等五种沉积类型, 东、西、中三湖区的沉积物中分別为0.21, 0.37, 0.14cm/a, 全湖年淤积总量为93*104t/a。3.湖泊污染加重起始于70年代, 磷除来自外源外, 内负荷引起的释放量达220.56t/a, 这对巢湖富营养化亦有着重要的影响。 |
| 关键词: 形成演变 现代沉积 水土界面 巢湖 |
| DOI：10.18307/1991.0103 |
| 分类号: |
| 基金项目: |
|
| Formation And Evolution Of Chaohu Lake And Its Recent Sedimentation |
|
Zhang Chen, Sun Shuncai
|
|
Nanjing Institute of Geography and Limnology, Acadcnua Simca, 210008
|
| Abstract: |
| Chaohu Lake, situated in Anhui Province, is one of the five largest fresh water lakes in the middle and lower reaches of the Changjiang River with a total area of 800 km2. The Chaohu Lake basin was formed in Mcsozoic era and early Cenozoic era, then developed into an alluvial] plain in the age of Pleistocene. Under the joint influences of climate, the corresponding changes of sea level and evolution of the channel of the Changjiang River, the basin began to be filled with water and became a lake in Late Holocene. The lake was formed about 2000 years ago. So Chaohu Lake is a typical riverine one with intense water body exchange. The sediments range from 5 to 6 ф in medium size and five major sedimentary types can be found in this lake, such as like-cuspat delta, open lake deposition, etc. The sedimentation rate is different in three parts of the lake, i.e. 0.21cm/a. in the cast, 0.37 cm/a. in the west and 0.14cm/a. in the middle of the lake. Total mass accumulation of the sediments in this lake is about 0.93 million ton/a. Sediment dating shows that serious pollution began in the 1970s. Sources of phosphorus arc both from allochthonous and inner loading(sediment), with about 220.56 ton/a releasing from the sediments, which has a great influence on the eutrophication of Chaohu Lake. |
| Key words: Formation and Evolution water/sediment Intcrfacc elements exchange Chaohu Lake |
