This is Part II of the study, aiming at analyzing and characterizing the cooling potentials of heat mitigation strategy (HMS) in landscape from both combating urban heat island (UHI) and alleviating human heat stress, in terms of air temperature reduction Delta T-a and Physiological Equivalent Temperature reduction Delta PET respectively. Here, different HMSs for landscape design were investigated, including vegetation (Green-HMS), high albedo pavement (Grey-HMS), water body (Blue-HMS) and hybrid of trees and landscaping surface (Hybrid-HMS). Parametric study was conducted with a validated urban open space model developed from ENVI-met V4. Through Delta T-a and Delta PET, the cooling benefits of each HMS were evaluated with the area coverage ratio R-HMS and the corresponding parameters. Generally, larger R-MHS would have both higher Delta T-a and Delta PET in various HMSs, except Grey-HMS. Hybrid-HMS demonstrates the greatest heat mitigation potentials, followed by Green-HMS, Blue-HMS and Grey-HMS. Hybrid-HMS has further cooling benefits compared to the landscape design with singular HMS. For Grey-HMS or Blue-HMS, its heat mitigation potential evaluated by Delta T-a is different from that by Delta PET, so both aspects should be considered in landscape design. Consequently, characterization charts of different HMSs are established, which would help the urban design practitioners create comfortable open spaces in hot-humid climate.
