| 摘要: | 都市空間中的建築物高度管制(height control)，除了可以塑造都市天際線(skyline)獨特的風貌外，亦能保護周邊自然地景(natural landscape)的可視性(visibility)。過去三十年，台北盆地內因缺乏由自然地景可視性保護觀點的建築高度管制，在都市快速發展與逐漸增長的建築量體趨勢下，已對原本盆地周圍自然地景的可視性帶來嚴重的衝擊。其中，台北市信義計畫區以建蔽率與容積率為基礎的建物高度管制，雖可塑造其都市天際線風貌，但卻對其東南側淺山系自然地景的可視性帶來顯著的影響。因此，本研究中以 1/1000 數值地形圖為基礎，建構高精度的「數值地表模型」(Digital Surface Model, DSM)，並採用ESRI ArcGIS軟體中的可視性分析工具(visibility analysis)，評估信義計畫區中建物開發，對其周邊地區原先所能看到自然地景可視性影響之程度(面積比例)。其中，觀測點(observers)的選擇，主要以信義計畫區周邊地區使用者聚集 密度較高之開放空間(公園用地與廣場用地)為主，以評估建築量體對戶外開放 空間使用者之自然地景可視性衝擊。而本研究中進一步搭配統計分析方法，針對觀測點建立不同指標因子之間的屬性差異(觀測點之類型、觀測點與自然地景之距離、觀測點與信義計畫區之距離、觀測點受到視角範圍內建物高度與之間的距離比例的遮蔽狀況等因子)，以評估不同屬性觀測點之指標因子與可視性影響之關聯性。
本研究進一步搭配假說與條件假說驗證的方式，探討可能產生不同的視覺干擾之指標因子，梳理出對各個觀測點之間所能看向自然景觀範圍之間的影響與變化，研究發現在信義計畫區未建立之前，可視面積隨著與自然地景距離越遠而越大，廣場用地之觀測點與此因子相關度最高，而視角內建築物高度距離比並不是隨著比例越大，可視程度就縮小。影響地景可以被看到的可能性最高的因數為視角內平均建築物高度，此相關度與一至兩公頃公園之觀測點相對較高，且開發后面積尺度較大的觀測點的可視面積，與距離信義計畫區的遠近有影響。從而
希望在未來規劃都市內開放空間之時，應根據不同土地現狀，考量與地景或建物之間的合理距離，與看向地景視角內之建築物高度，等因子對可視性所帶來的衝擊，建議通過先行評估的方式以進行用地及周邊環境建物的規劃，以降低不同開放空間對地景可視程度所產生的遮蔽性。
The height control over an urban space can not only reform a special view of city skyline but also preserve the visibility of the surrounding natural landscape. In the past three decades, due to the height control regulation that lacks the preservation of visibility of natural landscape, the visibility of surrounding natural landscape in the Taipei Basin has been severely impacted. Take Hsin-Yi District as an example, its height control regulation, based on building coverage ratio and floor area ratio, can reform the city skyline, but highly affects its southeastern visibility of natural landscape to the Shallow Mountain region. Therefore, this research, based on the
1/1000 Digital topographic map, will focus on the construction of Digital Surface Model (DSM) and evaluate the extent of the effect (i.e. the area ratio) from Hsin-Yi’s building development on its original visibility of natural landscape by applying the visibility analysis tool from ESRI ArcGIS. In this research, the surroundings open space with high user density (e.g. park lands, squares) are selected as the main observers, in order to evaluate the impact on its visibility of natural landscape from the building volume. In conjunction with statistical analysis,the research will form the feature differences against the observers in order to discuss the extent of the effect on the observers with various features.
In this study further with a way to verify the hypotheses and conditions of
hypothesis, indicator factors may produce different visual interference of the sort out between the various observation points. It can see the impact of changes in scope between the natural landscape. The study found that before the development, the visual area increases with the distance from the natural landscape, the observation point of the square has the highest correlation with this factor, while the height-to-height ratio of the building within the angle of view does not increase with the ratio. The most probable
factor that can affect the view of the landscape is the average height of the building within the view angle, which is relatively high compared to that of 1-2 hectares of park and the visual area of the larger observation area after development, And the distance from the Hsin-Yi District influence, hope that in the future planning within urban open space, should be based on a reasonable distance between the current situation different land zoning. To consider the landscape or buildings, visibility and other factors brought
about, it is recommended Through the first assessment of the way to carry out land and the surrounding environment of the planning, in order to reduce the different open space on the degree of visibility of the landscape caused by the shielding. |
