Ground-based observation data Three automatic weather stations (AWSs) and 13 automatic stations for soil hydrology (ASSHs) have been monitoring soil moisture and meteorological elements since 2001 and 2000, respectively. The location of these observation sites are shown in Table 2.1 and Figure 2.2. AWSs measure some of meteorological elements and soil moisture at four depths with a time interval of 30 minutes. ASSHs observe soil moisture and soil temperature at the depth of 3cm and 10cm. The time interval of the measurements at ASSHs is one hour until October 2004, after which it has been 2 hours due to electric problem. Because of different time interval between the instruments, the hourly soil moisture and meteorological variables were calculated using linear interpolation.