城市土地集约利用与用地扩展研究

Research for Urban Intensive Land Use and Urban Land Expansion——A Case Study in Urumqi City

城市扩展与城市土地集约利用存在内在联系。以干旱区绿洲城市乌鲁木齐的城市扩展特征为出发点,研究城市扩展与城市用地集约化间的动态相关性,评价城市对土地利用压力的响应能力。结果表明在1990—2014年,乌鲁木齐城市用地扩展呈现从缓慢扩展到快速扩展,再到中速扩展的特点;各时期城市用地紧凑度小,分形维数大,建设用地分布分散,城市用地的增加主要依靠于城区用地向内部的填充;对应时期内的城市土地集约利用水平呈现波动上升的特点,在近10年来城市用地集约化显著;经相关分析得出:城市用地的集约化与城市建成区面积的扩展速度关系不大,但受城市扩展的空间形态影响较大,建成区分散度、破碎度越大,则城市用地越趋于集约化发展。城市扩展与城市用地集约化二者的耦合关系可反映出一段时间内城市土地利用的效率或对用地压力的响应程度:当城市扩展强度>土地集约利用率,说明在城市化进程中存在土地浪费现象;当城市扩展强度<土地集约利用率,说明城市土地利用高效,应以经济—社会—生态三者协调发展为原则开展合理的城市土地集约利用。

There is an inherent link between urban expansion and urban land intensive use.The dynamic correlation between urban expansion and urban intensive land use is examined based on the urban expansion of Urumqi City in arid area,which can evaluate the city′s respons to land use pressure,in the period from1990 to 2014,the expansion in Urumqi City presented a characteristic of slow extension to rapid expansion to intermediate speed expansion;in each period,the compactness of urban land was small,the fractal dimension was large,the construction of urban land distributed,the increase of urban land mainly depended on the inward filling.During the same period,the level of urban intensive land use had a characteristic of fluctuant rise,and presented a significant reduction in the last 10 years.The conclusion is obtained by using the correlation analysis.The intensification of urban land has nothing to do with the speed of urban built-up area expansion,but is related to the spatial form of urban land.The bigger the distribution and fragmentation degrees are,the more intensive the urban land development is.The coupling relationship between urban land expansion and urban land intensification can reflect the efficiency of urban land use and the response degree to land use pressure in a period of time.When urban expansion intensity is greater than land intensive utilization rate,land wasting phenomenon exists in the process of urbanization;when urban expansion intensity is less that land intensive utilization rate,the urban land utilization is efficient,but the advance of reasonable urban intensive land use should be carried out by following economic,social and ecological aspects as a principle.