Analyze the retention characteristics of green roofs.

Due to the expansion of the urban area increases the impervious area and Inhibits the influence of evapotranspiration and infiltration of the water cycle. In addition, climate change causes extreme rainfall events, increase rainfall have greatly increased surface runoff in cities, Increase the intensity and depth of rainfall. These have led to a substantial increase in surface runoff in cities.

Green roof is one of the low-impact development measures. This study will improve the above-mentioned problems through the rainfall retention characteristics of green roofs, Calculate peak flow reduction and delay of arrival time. We have built a green roof observation system which including experimental group (green roof) and control group (no green roof) to obtain various observational data of the water cycle. Then input the data into the surface hydrological model for calibration and validation to analyze the retention characteristics of green roofs. Evaluate the flood reduction effect of green roofs in Taiwan.