Development of Global Land Surface Evapotranspiration and Water Balance Data Sets.

The global data sets with half-degree resolution of monthly evapotranspiration and water balance were produced using simplified water balance model and published global data set. Results are compared with information obtained by previous investigations that used different data sets and analytical approaches. In general, the quantitative features of hydrologic regimes at the earth's surface are successfully simulated. The value of water balance components at the terrestrial area also agrees well with those obtained by Baumgartner and Reichel. Particularly, the good correlation (r=0.89-0.95) was obtained from the comparison results between the computed annual evapotranspiration and observed values. The comparison of the latitudinal distribution shows that the large amount of water surplus in 45°N-75°N and deficit in 10°S-30°S rather than those of Legates and Mather. On the other hand, the latitudinal distribution of annual evapotranspiration shows very similar, except in middle-high latitudes region. Preliminary results suggest possible solutions to the problem of the evaluation of national water resources using these developed data sets.