With SDSM downscaling based on historical weather data, this thesis develops the future weather scenario with climate change consideration during 2015-2044, and then uses the scenario as input to the calibrated and validated hydrologic model, SWAT for water quantity and quality analysis, focusing on stream flow, sediment erosion and transportation at a watershed level. This thesis concludes that SDSM is able to simulate the daily historical temperature more efficiently than daily precipitation. Warmer winters and hotter summers may be expected during 2015-2044; higher mean and variance of the amounts of precipitation in summer may be expected without statistic significance; the future stream flows may have longer low flow periods extending from summer to fall, and severe annual water resources deficiency may be highly possible during 2015-2044 due to increased evapotranspiration. As a result, sediment transport capacity of reaches may decrease, and thus sediment deposition may be common phenomena.