Abstract

General Circulation Models (GCMs) are widely used tools to assess potential global climate impacts. However, GCMs’ outputs are difficult to use in regional impact studies because of their coarse spatial resolution; it is much more difficult at local level climate impact assessments. Hence, downscaling techniques are applied to bridge the spatial and temporal resolution gaps between what climate modellers are currently able to provide and what impact assessors require. The study aims to downscale station -scale climate scenarios in Talomo-Lipadas Watersheds, Davao City, Philippines for the years 2020, 2050, and 2080 under two scenarios (A1B and A2). It quantifies the increase/decrease of minimum temperature, maximum temperature, and precipitation. For the two watersheds under study, temperature minimum (Tmin) results show a likely slight increase from 0.159°C to 0.239°C; Tmin also shows an increasing trend under two scenarios (A1B and A2). For temperature maximum (Tmax), the two watersheds will experience prolonged periods of hotter temperature. For precipitation, simulated result shows heavy rainfall of 42.87% above observed data under A1B scenario. At the onset of the year, the two watersheds will experience wetter conditions in two scenarios. A1B scenario is projected to be “wetter” compared to A2 scenario. The highest rainfall of 335 mm is observed in June of 2050 (2041-2070) slice time period.

Keywords: SDSM; Statistical downscaling; Davao watersheds; Projected climate; Talomo-Lipadas; Davao climate