Hydrology model of extensive green roof

Storm water runoff in urbanised watershed such as roof top is fast flowing and overloading urban drainage system over time, causing flash flood. One of the source controls for this fast run off is installation of extensive green roof to the existing concrete flat roo~~Green roof is a close mimic of a natural watershed and has the effect of slowing storm water runoff in comparison with a conventional concrete flat roof. This dissertation relates the green roof runoff response to control system in order to understand the delay response of an extensive green roof in comparison with a conventional concrete flat roofyThe averaged time delay for the runoff to reach peak value (99.33 percents) between the conventional concrete roof and the green roof are 244.4 seconds and 252.05 seconds respectively for \nthe 1 to 60 slope configuration and the 1 to 200 slope configuration. The pulse responses for respective controlled volume models were simulated. The simulated results using the estimated time constant were then compared with respective average data acquired from each experimental setup using sum of squared of error. The first order control system response more closely represents the concrete roof than the green roof where the normalised sum of squares of errors (SSE) for the concrete (~ roofs and the green roof are less then 1 and 2 respectively. Finall~~s dissertation suggests a \ntheoretical relation the time constant to a hydrology parameter as an example for further possible \napplication of the finding ofthis dissertation.