楼兰古绿洲的河道变迁及其原因探讨西北历史环境研究

在干旱区，地表径流决定人类居住和生存的空间，是环境变迁的决定因素。楼 兰古绿洲的环境演变及其在４世纪末的最终消失都与塔里木河及孔雀河河水的空间分布密切 相关。石器时代至公元４世纪中叶以前，塔里木河与孔雀河合流，经库鲁克塔格山南麓东流，形 成面积广大的孔雀河三角洲，成为楼兰古绿洲繁荣与发展的基础；４世纪中叶，部分塔里木河水 在营盘附近歧道南流，离开了孔雀河三角洲，楼兰古绿洲开始衰败、萎缩；４世纪末，孔雀河、塔 里木河河水全部南流，孔雀河三角洲水源断绝，楼兰古绿洲衰废、消失。这其中，孔雀河三角洲 的自然地理特征是影响孔雀河河道发生变迁的基础因素；人类引流蓄水的捕鱼活动和屯田所 需河渠管理系统的兴废是影响河道变迁的重要人为因素。４世纪中晚期，塔里木河下游与孔雀 河的改道南流是在自然因素与人为因素的耦合作用下发生的。

A study on Changes of the River Courses on Ancient Loulan Oasis and the Reasons

This paper researches changes of the river courses on the ancient Loulan oasis from Neolithic age to the end of 4 century A. D. The main changes are: (1) About from 3 century B. C to the middle of 4 century A. D, Tarim and Konque River met near Weili, then flowed east into the ancient Loulan oasis, and had brought about prosperity of Loulan. (2) About at the middle of 4 century A. D, a part of water of Tarim-Konque River began to flow south near Yinpan, so named Yinpan River, and caused the decline of Loulan. (3) At the end of 4 century A. D, all the water of Tarim-Konque River flowed into the bed of Yinpan River, so the oasis turned into desert gradually because of lack of water. It were natural factors or human factors caused above changes, but the last change, all the water of Tarim-Konque River flowed south, is due to the coupling of natural factors and human factors.