摘要
本文根据实地考察,参考历史资料并利用卫片、航片,对居延海的形成、演变及其湖泊生态环境的变化进行了研究;并对终端湖和居延海的排泄,以及影响湖泊演变的因素等问题加以探讨。
The Juyan Lake is a well-known inland lake in China. Many scien-
tists at home and abroad have made investigation on it. In this paper,
the evolution process of the lake is studied through field investigation
and by means of the interpretation of satellite image and aerial photograph,
and the analysis of historical data. The following conclusions can be
resulted:
(1) In the early Quaternary, the Juyan Lake was a fresh water lake
With a vast area of water surface. This can be verified by the presence
of snail and fish fossil. From the map which was compiled by E. Norrin
et al through field survey in 1930-1933, it can be seen that the eastern
Juyan Lake and the western Juyan Lake had joined into an integral
whole With a water area of 1200 km sq. Because climate had become drier
since the middle Pleistocene and the Ruoshui River was formed in the
Holocene,the basin possessed a closed feature and its western branch formed
the western Juyan Lake.
(2) In historical period, the Juyan Lake evolved with the graduala
decrease in lake surface, and its general process was desiccation--saliniza-
tion--desertification.
(3) The drying up of the lake directly affected the ecological
environment. Fresh water habitats disappeared and fishes were extingui-
shed; vegetation degenerated from hygrophytes to xerophytes,halophytes and
psammophytes; biological productivity decreased and ecological environment
deteriorated.
(4) The water quality was fresher in the eastern Juyan Lake than
in the western Juyan Lake. Because water was both supplied and drained,
the eastern Juyan Lake don't has closed feature, but has the feature of a
river course lake. So the terminal must be the western Juyan Lake.
(5) The drying up of the Juyan Lake was related to hydrological
factors and water system evolution, especially to human activities.
出处
《干旱区资源与环境》
CSCD
1992年第2期9-18,共10页
Journal of Arid Land Resources and Environment
关键词
居延海
湖泊演变
干旱区
环境变迁
Juyan Lake
Lake Evolution
Arid Land Environmental Change
