城市格网化及其景观生态效应研究——以西安市为例

Study on Urban Grid Phenomenon and Its Landscape Ecological Effects──A case of Xi′an City

以西安市为例 ,对城市格网化的概念、成因及景观生态效应进行了系统的分析。城市格网化是一种大规模网状或格状的土地利用空间结构现象 ,技术、功能优先的现代城市规划方法是其主要成因。景观生态效应主要表现在自然生境的破碎化、城市景观的同化、开放空间环境的退化等方面。减小格网化现象的负面效应有赖于城市景观生态重建 ,结合西安市实际提出了若干措施。

Urban grid phenomenon and its landscape ecological effects are analysed in this paper. Urban grid phenomenon is defined as a grid or net-like urban land-use pattern, which is characterized by grid-shaped road system and regular patch forms. Functionalism and single-purpose planning is the main reason of the formation of urban grid. In the case study of Xi′an, traditional Chinese urban planning thoughts also contributes to the formation of urban grid phenomenon. The measurement of Xi′an urban grid phenomenon is conducted with two formulas. It shows that the density of the urban grid decreases from inner city to suburb; and the patches are predominantly regular polygon-shaped. The negative effects of urban grid phenomenon include the fragmentation of wildlife habitats; uniformity of urban landscapes; and degradation of public open spaces. To abate the negative effects and restore the urban landscape, some new planning thoughts and approaches are applicable: creation of the public open spaces; protection of the micro-landform differences; preservation of the wet land system and accommodation of nature into the city.