唐以来方家沟流域地貌的演变与复原  

Geomorphologic changes and restoration of Fangjiagou Drainage Area from early Tang Dynasty

作　　者：姚文波[1] 侯甬坚[2] 高松凡[3] 

机构地区：[1]西安市社会科学院莲湖区发展研究中心,陕西西安710014 [2]陕西师范大学西北历史环境与经济社会发展研究中心暨中国历史地理研究所,陕西西安710062 [3]中国科学院地理科学与资源研究所,北京100101

出　　处：《干旱区地理》2010年第4期509-517,共9页Arid Land Geography

基　　金：陕西师范大学"211工程"三七重点学科建设项目"西北地区人文社会与资源环境的协调发展";国家科技支撑计划课题(2006BAD09B09)资助成果

摘　　要：以方家沟沟掌台地上的十六国末期赫连伦墓地和沟口汉墓群为依据,确定出方家沟流域现代侵蚀沟的地貌年龄上限为北魏太武帝始光二年(425 A D)。结合现代侵蚀沟地貌年龄计算公式,最终确定其现代侵蚀沟初始侵蚀年代为唐贞元五年(789 A D)前后。根据洪河流域20多年来的侵蚀模数值,计算方家沟流域1 129 a来的侵蚀总量。在1∶10 000地形图上测得方家沟流域现代侵蚀沟的空腔体积。在此基础上,以今天地貌为基准,复原其地貌至唐初,并虚拟绘制出地貌复原图。结果显示,至少到唐初,方家沟流域还是低丘宽谷地貌,不存在深陷的V型谷,V型谷形成的时间要稍晚一些。这种现象普遍存在于陇东盆地泾河的三、四级支流和部分一、二级支流流域。复原结果很好地支持了历史时期黄土高原水土流失日趋严重这一结论。This paper focuses on the research of landform restoration of the entire watershed - Fangjiagou drainage area, with some breakthrough in research methods and contents. The upper limit of the initial development period of the contemporary erosion ditch is obtained by using the tomb relies＇ sites, and then its initial developmental period is gotten by using geomorphic age formula of the contemporary erosion ditch of the loess plateau. The final result of the contemporary erosion ditch＇s geomorphic ages is got by making the comparative analysis of the two results. The historical landform recovery of the entire watershed is achieved by integrating the landform age, erosion modulus of the Honghe River basin for nearly 20 years, and the data of cavity of the contemporary erosion ditch on 1 ： 10 000 landform map. It is ascertained that the geomorphologic age of the contemporary erosion ditch of Fangjiagou drainage area was 425 A. D. , the 2nd year of Shiguang, Taiwu Emperor, Northern-Wei Dynasty. This is the result based on the information obtained from the Cemetery of Lun Helian in the Sixteen Countries Period （317 - 420 A. D. ） and the Tombs of the Han Dynasty in Fangjiagou Mizoguchi. With the formula of geomorphologic ages of the contemporary erosion ditch, the age in this area was finally defined as around 789 A. D. , the 5th year of Zhenyuan, Tang Dynasty. The total amount of erosion in this area since 1 129 has been calculated based on the da- ta in the recent 20 years. The volume of the contemporary erosion ditch in this area was measured on a topographic map （ 1 ： 10 000）. The landforms were restored to early Tang dynasty, and a geomorphologic map was virtually de- signed in accordance with the data obtained and with the present landforms in this area. The results show that at least in early Tang Dynasty, the landform was a low-lying hill and roomy valley, and there was no chasmal V-model erosion ditch. It was estimated that the V-model erosion ditch was shaped later. It was also found that this

关 键 词：方家沟 地貌复原 唐代初期 

分 类 号：S157[农业科学—土壤学]