Remotely sensed data were obtained from MODIS products (see details in Table 1) because it provides surface observations for regional/basin water management. MODIS is the key instrument aboard the Aqua and Terra satellites, acquiring data in 36 spectral bands. The primary remotely sensed inputs to the METRIC algorithm are normalized difference vegetation index (NDVI), surface emissivity, broadband surface albedo, and land surface temperature. The MODIS albedo is calculated as (Liang 2001):where α is the broadband albedo and r_n represents spectral reflectance in band n.