城镇化的动力机制是城镇化研究的核心问题。由于地理区位、自然资源、历史传统和人文等因素的影响,西藏高原城镇化的动力与其他区域有着不同的特点。本研究在对"一江两河地区"城镇化现状特征分析的基础上,分阶段对该地区城镇化的动力机制及其演变进行了研究。重点分析了西藏和平解放后,中央实施的援助西藏的特殊政策对城镇化的作用,认为援藏政策是西藏城镇化的核心动力,但同时也强化了西藏"非典型的二元结构",城镇缺乏自然发育和自觉成长的过程,缺乏内在的经济利益驱动和活力,经济职能弱,辐射带动能力不足。"一江两河"地区城镇化水平的提高主要来源于城镇外来人口的机械增长,本土非农化进程缓慢,城镇化在改善当地农牧民生活水平方面的作用没有充分发挥出来。从推进本土农牧民城镇化进程的角度出发,并充分考虑援藏政策对西藏城镇化的作用,提出今后"一江两河"地区城镇化动力系统优化的思路,为其他具有高原环境特征和特殊社会背景地区的城镇化的研究提供借鉴。

Urbanization dynamics is one of the most important part of urbanization studies.The dynamical mechanism of urbanization of Tibet is different in character from other parts of China because of its special location,natural resources and social background.This study analyzed the evolvment of urbanization dynamics in "Three-River Area" which is the fastest developing and the most densely populated area of Tibet.The effect of Aid-Tibet policies to the development of urbanization since peaceful liberation of Tibet was analyzed emphatically.We found that Aid-Tibet project and policies is the main dynamic of urbanization in "Three-River Area",but the Aid-Tibet policies also strengthened the "atypical dualistic structure" which cause the urban unable to absorb the excessive labor forces from rural area because of the weak economic function of cities and town of "Three-River Area",and floating population become the main strength for speeding up the process of urbanization in the new era.Aid-Tibet policies will continue playing an important role in urbanization process of Tibetan Plateau.For accelerating the urbanization process of local farmers and herdsmen,optimization scheme of urbanization dynamics was proposed in our study.