Abstract: The relationship between radiation and water in oak forest was studied with the combination of water cycling and radiation energy transfer processes. The results show that water movement direction and water-exchanging quantities are varied with different radiations in the forest layer and ground layer. About 74. 5% of net radiation is used for evaportranspiration which accounts ior 77. 45 % of rainfall, so most radiation is mainly consumed on water cycling. In addition, the impact of radiate energy on snow-melting process was studied. It is found that mixed forest is an ideal runoff model of snow-melting because of its proper radiation characteristics as compared with other two forest types. 

Key words: radiate energy, evaportranspiration, snowmelting process