| dc.description.abstract | Although the annual rainfall in Taiwan is abundant, its spatial and temporal distributions are quite uneven. Owing to steep terrains, rivers in Taiwan are often short and rapid causing challenges in water resources managements due to limited reservoir capacities. Whenever droughts occurred, the effective water storage of our reservoirs are often unable to meet societal needs. For example, the effective water storage of the Shihmen Reservoir was only 33% on May 17, 2020, and only 50% by the end of October. Furthermore, impacts of climate change will affect functions of reservoirs to support water resources managments. The purpose of this study is to investigate impacts of climate change of the Shihmen Reservoir. Projections of the IPCC AR5 gridded hydrometeorological data from the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP), including a total of 34 General Circulation Models (GCMs) with 4 Representative Concentration Pathways (RCPs), were adopted to perform hydrological simulations of the Shihmen Reservoir with the Taiwan Water Resource Assessment Program to Climate Change (TaiWAP) model. Changes of rainfall, temperature, and inflow were analyzed with annual and monthly scales.
Projections of annual rainfall, temperature, and inflows of the Shihmen Reservoir Watershed show an increase trend from 2021 to 2100 based on the average of all GCMs adopted in this study. On the monthly scale, significant increases of rainfall and inflow were observed for the wet season from May to October. Higher probabilities of heavy rainfall during the wet season should be noted. With limited reservoir capacity, challenges of adopting suitable adaption measures for sustainable water resources managements will be more profound to the Shihmen Reservoir watershed. Considering the uncertainty of climate projections, probabilities of increase or decrease in rainfall, temperature, and inflow were calculated based on numbers of GCMs having increase or decrease projections at 4 different future time periods (namely near future, mid future, far future and the end of the century). Meanwhile, the maximum and minimum projected changes in rainfall and temperature were given with the corresponding GCMs in tables for cases of outliers to provide comprehensive information for future studies. | en_US |