以衛星影像及碎形理論探討都市綠空間之發展結構－－以台北市信義計畫區為例

ANALYZING URBAN GREEN SPACE BY USING FRACTAL THEORY AND REMOTELY IMAGERY-A CASE STUDY OF SHIN-YI PLANNING AREA IN TAIPEI

都市發展過程中，土地利用隨都市多元化而漸趨複雜，並依其政治、經濟、文化和社會之差異而有不同，其形成一個自發性的系統，所以都市常被視為一個自我組織的有機體。自我組織現象的形體一般皆存在著自我相似度或是自我仿射性，而具有自我相似度特質的空間形體即具有碎形特性。因此許多都市空間結構的研究中，逐漸發現傳統的歐氏幾何學已不足解釋都市空間結構所具有的特性，而碎形維度則是有別於傳統歐氏幾何的整數維度，並以分數維度來描述存在於大自然中的形體，碎形幾何的概念主要是一些數學函數的集合，以迭代方式取代特徵尺度的量測方式來形容幾何物體。遙測資料被認為是監測都市環境變化重要且有利的工具。因此本研究以1994、1996、1998及2000年台北市信義計畫區之SPOT和Landsat衛星影像，為監測都市綠空間變化的資料。將影像監督性分類後之結果，抽取地面覆蓋為綠地之資料，視為綠空間，且以地理統計方法求取信義計畫區綠地之碎形維度及空間發展的自我相似組識現象。其結果顯示信義計畫區內的綠空間從1994年至1996年皆增加，而至2000年卻減少，各年度之碎形維度值皆隨最大間距範圍擴展而增加，並且碎形維度值變化之情形以1996年最高，其次為1998年、2000年、1994年，而以多尺度的最大間距範圍量測信義計畫區綠空間的碎形維度之結果發現，若將1994年至2000年的信義計畫區綠空間碎形維度曲線圖顯示空間發展存在著自我組織的現象，且歷年碎形維度變化之斜率逐漸趨於一致，故信義計畫區之綠空間發展在1996年後即呈現一特定的格局發展。

In urban-development process, the urban land-use following many-faceted urban depending on political, economical, cultural and social conditions becomes complex and dissimilar forms being a spontaneous system. Under this forming process an urban can be viewed as a self-organizing organism displaying self-similarity or self-affinity fractal phenomena in space. Therefore, many spatial structure studies of urban mentioned that Euclid geometry couldn't explain the spatial characteristics of urban due to different form development of urban with different environment conditions. Fractal dimension, using non-integral dimension to describe many objects in nature, is different from conventional integral Euclid dimension. However, fractal geometry, substituting feature scale to descript geometry objects, bases on a set of mathematical functions. Meanwhile, remotely sensed imagery is essential tool for urban environmental monitoring. In this study, the remote sensing data and variogram were used to calculate the changes and fractal dimensions of green spaces in Shin-Yi Planning area in Taipei in 1994, 1996, 1998 and 2000. The green space data were extracted from SPOT and LAN SAT images of Shin-Yi planning area. The results illustrated that the green spaces of this study area increased during 1994 to 1996 and then decreased during 1996 to 2000. The order of fractal dimensions during 1994 to 2000 were 1996> 1998>2000> 1994. Moreover, the spatial development of Shin-Yi planning area displayed self-organizing phenomena during these seven years and consisted in a tendency from 1996 to 2000.