无定河流域城镇聚落的历史演变与人地耦合

地处黄河中游的无定河流域,是典型的过渡地带和生态脆弱地区。通过分析流域城镇格局的历史发展过程,以及这一过程中的人地耦合关系,结果表明：流域城镇枢纽地区,在唐代及以前为弓形,城镇空间布局的影响因素以自然因素为主;唐末以后为三角形,城镇空间布局的影响因素以人文因素为主。当代流域城镇格局继承了历史发展的脉络,但城镇发展动力主要是长城沿线的资源开发和城镇建设,这些活动对局部地区的植被覆盖产生了冲击型影响;同时以退耕还林、防风治沙等为代表的生态保护政策也已经显现出积极的效果。建议流域的城镇发展要合理确定人口与建设用地的发展规模、集中在榆横和靖边等主要城镇周边布局,并且以河流为骨架构建生态屏障。

The historical evolution of urban settlements and man-land coupling in Wuding River Basin

The Wuding River Basin,located in the Loess Plateau of the middle reaches of the Yellow River,is a typical transitional zone and ecologically fragile area in history.Based on the analysis of the historical development process of urban pattern and the coupling relationship between human and land in this process,this paper puts forward the countermeasures and suggestions for the future urban development and ecological protection of the basin in combination with the current situation of urban development.The main findings are as follows:the development and evolution of the urban hub area in the basin was bow shaped in the Tang Dynasty and before,when the natural conditions were better,and the urban spatial layout was mainly based on natural factors;the hub area after the Tang Dynasty presented a triangle pattern,and the urban spatial layout was mainly based on human factors;the contemporary urban pattern of the basin inherited the context of historical development,but the driving force of urban development was mainly based on resources along the Great Wall.The human activities have an impact on the vegetation coverage in some areas;at the same time,the ecological protection policies,such as returning farmland to forests,wind prevention and desertification control,have exerted positive effects.It is suggested that the development of the river basin should be reasonably determined and concentrated around the main cities and towns in combination with the national strategic positioning and regional ecological environment bearing capacity.In addition,the ecological barrier and key prevention and control areas are constructed with the river as the backbone.