都市地表不透水率之預估與分析：以台中市為例

都市的高密度開發造成地表不透水率日漸升高，不僅影響地表逕流之現象，亦改變區域之微氣候，並造成都市土壤及河川之生態問題。過去研究顯示台灣的都市透水性能日漸惡化，然而，這些數據尚無法運用到其他都會地區，同時，也未進行相關之檢討與修正，且對於不透水率亦無法以圖像化方式呈現。因此，本研究以台中市為例，利用分層隨機抽樣的方式並修正公共設施之抽樣方法，進行274個樣本之實測調查，同時加入開發率及預估與實測誤差之修正，建立台中市不透水率預估模式。研究結果顯示各使用分區的不透水率值為：住宅區87%，商業區94%，工業區85%，公園綠地28%，學校74%，機關用地87%，其它公共設施74%。經估算台中市整體不透水性率47.7%，而若僅考慮都市已開發區之不透水率，則其值高達72.2%。由不透水率分布圖顯示與台中市航照圖所呈現開發的趨勢一致，且中區、西區、北區等舊都市密集區域其不透水率均高達90%以上，配合敏感度分析可發現未來要改善台中市透水性能，可針對住宅區、道路用地等進行改善其成效最佳。本研究對都市不透水率進行完整之量測、預估與繪製，將可做為未來不透水率之改善對策之參考依據。

關鍵字

地表不透水率；預估模式；使用分區

並列摘要

Highly development of the urban causes the rising of percentage of impervious area (IMP). It effects the phenomena of surface runoff, changing the micro-climate and bringing about the ecological problem of soil and stream. Previous study revealed that the problem of imperviousness of urban in Taiwan was getting worse. However, the data investigated before could not apply to other cities and the result was not revised and presented as imagination. Therefore, this research used the stratified random sampling to investigate 274 samples in Taichung city and the prediction model was set up and revised by the ratio of development and prediction error. The result showed that the average IMP was 87% in residential area, 94% in commercial area, 85% in industrial area, 28% in parks, 74% in schools, 87% in government organizations, 74% in public facilities. The total value was 47.7% in Taichung and 72.2% in developed area of Taichung. The distribution maps of Taichung showed the obvious correlation to the aerial photo and the IMP of Central, West and North District are higher than 90%. The best way to improve the performance of perviousness was to restrain the IMP in residential area and road area by the sensitivity analysis. This research finally completed the measurement, prediction, and mapping of IMP. It will be an important strategy of improving the IMP in urban area.

並列關鍵字

Percentage of impervious area ； Prediction model ； Zoning

參考文獻

黃志弘、廖明誠(2002)。都市地區中降水入滲機制問題探討。I建築學報。40，99-109。

林憲德、林子平(2001)。基地保水性能評估之研究。建築學報。38，67-82。

Arnold, C. L.,Gibbons, C. J.(1996).Impervious surface coverage: The emergence of a key environmental indicator.Journal of the American Planning Association.62(2),243-258.