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中国沙漠 ›› 1999, Vol. 19 ›› Issue (2): 184-186.

• 论文 • 上一篇    下一篇

禹门口南黄河东岸沙丘初步研究

马志正1, 胡晓猛2, 李有利2   

  1. 1. 山西师范大学地理系, 临汾 041004;
    2. 北京大学城市与环境学系, 北京 100871
  • 收稿日期:1998-11-09 修回日期:1999-03-01 出版日期:1999-06-20 发布日期:1999-06-20
  • 作者简介:马志正(1937-),男,教授。主要从事环境灾害与地貌学方向研究。
  • 基金资助:
    山西省自然科学项目(971023)与国家自然科学基金(49601003)联合资助

Dunes on the East Bank of the Yellow River to the South of Yumenkou, Shanxi

MA Zhi-zheng1, HU Xiao-meng2, LI You-li2   

  1. 1. Department of Geography, Shanxi Normal University, Linfen 041004, Shanxi, China;
    2. Department of Urban and Environment Sciences, Peking University, Beijing 100871, China
  • Received:1998-11-09 Revised:1999-03-01 Online:1999-06-20 Published:1999-06-20

摘要: 在禹门口南山西省河津、万荣县境内黄河阶地上发育了一些固定、半固定沙丘,注入黄河的汾河将这些沙丘分成了南北两部分。北部的沙丘多在海拔400m左右,高出现代黄河约35m,位于黄河的第二级阶地上,由两条南北向的沙垄和两垄之间分布的抛物线形沙丘构成特殊的景观。这些抛物线形沙丘一般高度约7~8m,背风面突出,迎风坡坡度一般为15°~20°,背风坡坡度一般大于40°。风沙堆积下伏的河流堆积物的14C年龄为26.40±0.8kaBP,表明沙丘形成于距今26ka以来。南部沙丘海拔高度近500m,高出现代黄河水面150m,覆盖于黄河第三级阶地之上。一个天然剖面揭示,第三阶地的底部为黄色中粗砂与灰绿色粉砂粘土互层,中部为灰黄色黄土,顶部为黄色风沙层。在黄土地层中可以识别出S1古土壤和位于风沙堆积下面的可能为L1SS1的弱成土层。由此推断风沙堆积于距今3万a以来。黄河阶地上的沙丘是在特殊的地区和特定的时期;强大的风力、丰富的沙源和气候变干条件下形成的。虽然东岸沙丘已是固定、半固定沙丘,但沙化仍然是该地区的一个问题。由于3~4a前开始在丘前洼地栽种苹果树,破坏了下风向沙丘迎风面的植被,造成了原来已固定沙丘的活化,在沙丘顶部生成了新的小抛物线形沙丘,高度大于1 m。沙丘上裸露的树根指示表土已被侵蚀0.3 m。南部沙丘区的风蚀作用也很强,例如,万荣县裴庄乡西范村北一片柿树林的树根由于风蚀已经裸露1.2 m。

关键词: 沙丘, 局部环境, 气候变化, 人类活动, 黄河

Abstract: To the south of Yumenkou, there are some fixed and semi fixed sand dunes dist ributed on terraces of the Yellow River in the Hejin and Wanrong counties of Shanxi Province. The Fen river divided the dunes into two parts. The dunes in the north part, about 400 meters above the sea level and 35 meters above the present table of the Yellow River, are on the second terrace. They are composed of two sand ridges trending N-S and parabolic dunes between ridges. The parabolic dune s are 7~8 meters high and have convex downwind, their stoss slopes are 15°~20°, downwind slopes are around 40°. The alluvial sediments of the second terrac e was dated to be 26.40±0.8 ka BP by the 14C method, which indicate that the dunes were formed since 26 ka BP. The dunes in the south part, about 500 m above the sea level and around 150 m above the water surface, are on the third terrace of the Yellow River. A natural profile shows t hat the third terrace is composed of interbedded yellow coarse medium sand and siltclay grey green layers in the lower part, grey yellow loess (silts) in the middle part, and aeolian sands on the top. In the loess, the S1 paleosol and a weaker paleosol, properly the L1SS1 and just below the aeolian sands, can be distinguished. It suggested that the aeolian sands were formed since 30 ka BP. The dunes on the terraces of the Yellow River are formed under strong wind, ri ch sand supply, and arid climate in this special area and during the special period. Though the aeolian sands are existed in forms of fixed or semi fixed dune s, the desertification is still a problem in this area. Some fixed dunes in the north part reactived because vegetation at inter dunes' low lands were replace d by apple trees 3~4 years ago. New parabolic dunes over 1 m high formed on the top of the older dunes. Exposed tree roots indicate that the surface soil and sand have been eroded about 0.3 m. The wind erosion is also very strong in the south part. For example, roots of persimmon trees to the north of Xifan village in Wanrong County have been uncovered about 1.2 m.

Key words: Dunes, Local environments, Climatic change, Human activity, The Yellow River

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