都市地區降水入滲機制問題探討

都市地區大量的建物、不透水舖面與瀝青路面取代原有地表，致使都市地盤中普遍含水量不足；導致土壤內部生態失去平衡、都市熱島效應等，都是近年來引起關注的問題焦點。藉由降雨、土壤滲透係數（K値）與有效入滲總量之實證分析，本文針對台北市文山地區降雨入滲之機制進行探討，正確得出該區實際之入滲狀況。結果顯示：都市地區地表土壤實際之滲透係數因區外客土與擾動之故產生個別性差異；實際入滲總量與區域降雨形態、土壤滲透係數、透水面積比例存在密切關係；入滲性能較佳之區域可涵容入滲性能較差區域之部分地表逕流。欲符合綠建築評估中基地保水指標之最終精神　W加實際有效入滲總量，都市開發管制也應依前述分析，周延規範各影響因子，以提高都市基盤之含水量及滲流量，發揮都市降水入滲管制之立法原旨。

關鍵字

滲透係數；降雨；有效入滲總量；都市生態；保護

並列摘要

The high-density construction in the urban areas of Taiwan makes the soil surface almost impermeable. This leads to an ecological unbalance in the soil, the heat island effect etc. Based on empirical analysis of rainfall, and soil hydraulic conductivity, a practical analysis of the effective infiltration area in the Wen-Shan district of Taipei can be made. Results of the empirical survey in this study show that the effective hydraulic conductivity in an area is positively related to the rainfall, the coefficient of soil hydraulic conductivity and the effective infiltration area in this district. These factors of hydraulic conductivity should be considered in formulating urban regulations, so that underground water can be preserved during development and construction.