金沙江白鹤滩河段下切速率初步研究  

INCISION RATES OF THE BAIHETAN SECTION OF THE JINSHA RIVER

作　　者：黄典[1] 杨达源[1] 李郎平[1] 石安池[2] 陆飞[2] 葛兆帅[3] 胥勤勉[4] 

机构地区：[1]南京大学地理与海洋科学学院,南京210093 [2]中国水电顾问集团华东勘测设计研究院,杭州310014 [3]徐州师范大学城市与环境学院,徐州221116 [4]中国地质调查局天津地质矿产研究所,天津300170

出　　处：《第四纪研究》2010年第5期872-876,共5页Quaternary Sciences

基　　金：高等学校博士学科点专项科研基金项目(批准号:20060284028)资助

摘　　要：金沙江白鹤滩河段为金沙江上的改向河段,河谷地貌具有强烈深切的特点。文章主要根据该河段所具有的非常特殊的阶地堆积,进行该河段深切地貌过程及其深切速率变化的研究。金沙江白鹤滩河段,近百万年以来的深切幅度及其深切速率要比金沙江其他河段大一些。该河段2.35万年以来的平均深切速率,比4.65万年以来要大得多,主要原因可能是在2.35万年以前该河段曾经有过大量块石为主的堆积充填阶段,之后成为第1级阶地上的堆积物。与此同时,在2.35万年之后的全球末次冰期鼎盛时期,金沙江白鹤滩河段恰恰是强烈侵蚀深切时期。The Baihetan section of the Jinsha River is from Hulukou Town （ Ningnan County, Siehuan Province） to the confluence （Xixihekou）of the Xixihe River with the Jinsha River,54km long. In B aihetan Town a large hydro-station is under construction. Owing to deep river valleys and steep mountain slopes, the Baihetan section is very difficult of access,and few geological or geomorphological survey were conducted. In order to meet the need of hydraulic engineering, we investigated the section in recent two years. Previous works pointed out that the Baihetan section was a diverted river section： in this section, the Jinsha River originally flowed southwards, but about 1Ma ago, flowed northwards. In the Baihetan section there are no typical terraces like those in other river sections of the Jinsha River, but there are extraordinary terraces composed of big rock blocks. Our investigation in Mianshawan, Xinhuawucun,the Baihetan building site, Cuijiatuo, and Yuba found that during the last 1 Ma, the average incision depth and rate of the Baihetan Section were larger than other sections of Jinsha River. The average incision rate in the last 23.5ka is much larger than that in period of 23.5 -46.5ka. The strong incision time of the Baihetan section should be after 23.5 ka occurred, that is,the last glacial maximum.

关 键 词：金沙江自鹤滩河段 河流阶地 深切速率 盛冰期 强烈深切 

分 类 号：P931.1[天文地球—自然地理学] P343.5