The relative impacts of climate change and urbanization on the hydrological response of a Korean urban watershed

摘要

We assessed the relative hydrological impacts of climate change and urbanization using an integrated approach that linksnthe statistical downscaling model (SDSM), the Hydrological Simulation Program—Fortran (HSPF) and the impervious covernmodel (ICM). A case study of the Anyangcheon watershed, a representative urban region in Korea, illustrates how the proposednframework can be used to analyse the impacts of climate change and urbanization on water quantity and quality. The evaluationncriteria were measurements of low flow (99, 95, and 90 percentile flow), high flow (10, 5, and 1 percentile value), pollutantnconcentration (30, 10, and 1 percentile value), and the numbers of days required to satisfy the target water quantity andnquality for a sensitive comparison of subtle impacts of variations in these measures. Nine scenarios, including three climatenscenarios (present conditions, A1B, and A2) and three land use change scenarios, were analysed using the HSPF model.nThe impacts of climate change on low flow (34Ð1–59Ð8% increase) and high flow (29Ð1–37Ð1% increase) were found to benmuch greater than those on the biochemical oxygen demand (BOD) (3Ð8–10Ð0% decrease). On the other hand, the impactsnof urbanization on water quality (19Ð0–44Ð6% increase) are more significant than those on high (1Ð0–4Ð4% increase) and lownflow (11Ð4–25Ð6% decrease). Furthermore, low flows are more sensitive to urbanization than high flows. The number of daysnrequired to satisfy the target water quantity and quality can be a sensitive criterion to compare the subtle impacts of climate andnurbanization on human society, especially as they are much more sensitive than low flow and pollutant concentration. Finally,nurbanization has a potent impact on BOD while climate change has a high impact on flow rate. Therefore, the impacts of bothnclimate change and urbanization must be included in watershed management and water resources planning for sustainablendevelopment. Copyright  2010 John Wiley & Sons, Ltd.