b'BLUE-GREEN ROOF SYSTEMS FIGURE 5: WATER BALANCES AND TEMPERATURES.Figure 5 shows moisture and tempera- of BGR to climate change by imple- recirculating pumps. Beneath the plat-ture results from the BGR; these includementing a weather-adaptive rain runoffform is a fully enclosed crawlspace to be rainfall intensity, the water level (WL)control mechanism that communicatesmaintained at controlled temperature of the blue layer, the soil moisturewith a downstream rainwater recircu- conditions. The experimental setup is content (MC) and the temperatures oflating cistern at the site. For Phase 3 ofthe same as Phases 1 and 2 (Figure 2), the soil substrate and the plants. Figurethis project, a 5 m by 3 m roof plat- with changes in roof size, instrumen-5 shows that when the water in the BLform was built at BCIT. The platformtation and water control capabilities. is depleted, the soil moisture contentholds two 2.5 m by 3 m roof modules,Water level sensors were added to each decreases, due to increased plant waterside by side, connected to two cisternscistern. Phase 3 is being implemented in intake and ET, down to wilting point,along with water control valves andtwo phases.and the roof temperatures rise. At this stage, evaporative cooling is no longer available to dissipate heat from the BGR, and convective heat dissipation becomes predominant.The solar reflectance (albedo) of the BGR and the BR with pavers on top were also measured over one summer and compared to those of two conven-tional roofs built for reference: one roof having a white membrane and the other a black membrane. For the BGR, the reflectance decreased over the summer from 0.22 to 0.17 (affected by the moisture in the plants). For the blue, the white and the black roofs, the reflectance was 0.17, 0.69 and 0.06, respectively. More representative data that accounts for performance deteriora-tion over time will be collected.PHASE 3PRELIMINARY RESULTS AND PLANS Phase 3 of this project aims to improve the moisture and thermal resilienceFIGURE 6: PHASE 3AERIAL PHOTO OF THE EXPERIMENTAL SETUP.FALL/WINTER2025 19'