长江三峡地区坡地发育初步研究

PRELIMINARY RESEARCH ON SLOPE DEVELOPMENT IN THE THREE-GORGE AREAS

坡地发育是地貌学研究的基本问题之一。三峡地区坡地发育的研究对三峡库岸稳定性的评估和三峡移民的土地开发具有十分重要的意义。首先从概括坡地发育的研究进展 ,阐述科学家们对坡地发育的不同看法入手 ,引出三峡地区坡地发育的特殊性。初步研究认为三峡地区的坡地发育具有分段式分进的特点 ,包括中山尖峰陡坡的剥蚀后退过程 ,山顶缓坡的风化剥蚀夷平的过程 ,上段斜坡的片流坡地侵蚀过程 ,下段陡坡的剥蚀后退过程 ,山麓堆积缓坡的剥蚀过程等。通过分析三峡地区坡地的五种坡段的成因、现状、发展趋势以及它们对三峡库区的稳定性和三峡移民的土地开发的影响 ,预测未来的三峡库岸 ,大部分为剥蚀陡坡 ,部分为崩塌滑坡陡坡 。

Slope development is one of the elementary issues of geomorphology.It is very important to study the slope development in the Three Gorge areas for evaluating the stability of the banks of the Three Gorge Reservoir and exploiting the lands for immigrants.Starting with summarizing the progress of slope development research and illustrating various opinions about slope development,this paper deals with the particularity of the slope development can be classified into following subsections:the process of recessoin of abrupt slopes by denudation at the spiky top of medium mountatains,the process of flattening of gentle slopes by weathering and denudation on the top of mountains,the process of erosion of upper gradient slopes by sheet flow,the process of parallel recession of lower abrupt slopes by denudation or landslip and the process of denudation at the foot of mountains.By analyzing causes of formation,present status,development trends of the five kinds of slope subsections and their effects on the stability of the reservoir areas and exploitation of the lands for immigrants,authors predict that most of the banks of the Three Gorge Reservoir would be based on the abrupt slopes,some on the slopes of landslip.The construction of towns would be focused on the project of defending the banks of the Reservoir and slope areas.