其他摘要：In order to reveal the spatial variation of the relationship between forests and runoff and explore the mechanism numerical simulations of the responses of evaporation and runoff to the dynamic changes of vegetation over the Suomo basin (a tributary of the Yangtze River in the mountain region of southwestern China) are conducted under different temperature change scenarios by using the coupled model SSiB4T/ TRIFFID (Plant Dynamic Vegetation Model TRIFFID and TOPMODEL are integrated into the land surface model SSiB4). The impacts of temperature changes on forest-runoff relationship and the mechanism are ana-lyzed. The results of control test show that in wet season canopy wetness fraction is high in the subalpine re-gion of southwestern China duo to low temperature. Transpiration is the minimum among three components of evapotranspiration. Transpiration of forests is no significant difference with transpiration of grass and shrub. The evapotranspiration of the basin increases and reaches its maximal value during the period of C3 grass succession into shrub and then decreases during the period of shrub succession into forest and reaches its minimal value which may be less than bare soil evaporation. As a result forests increase the total runoff of the basin. A decrease in temperature by 1.5°C enhances such effect of forests duo to more decrease in water loss through canopy interception evaporation and transpiration of forests. An increase in temperature by 2°C enhances the rate of transpiration and evaporation of forests more than that of grass and shrub. As a result forests have no significant effect on runoff. Temperature rises to 5°C will cause forests turn to reduce runoff duo to more significant increase in water loss through canopy interception evaporation and transpiration of forests. As elevation decreases (temperature increases) in the mountain region of southwestern China the role of forests to increase runoff will change to be that forests have no significant effect on runoff and forests reduce runoff. The results also indicate that canopy temperature and canopy resistance of forests are more sensitive to temperature changes than that of grass and shrub. As a result canopy interception evaporation and transpiration of forests are more sensitive to temperature changes which cause that more significant increase or decrease in forest canopy evapotranspiration with temperature increase or decrease than that of grass and shrub. Through such mechanism changes of temperature cause the changes of forest-runoff relationship.
关键词：森林与径流关系;空间变化;植被与水文模拟;机理分析;长江上游山区
其他关键词：Forest-Runoff Relationship; Spatial Variation; Dynamic Vegetation and Hydrology Modeling; Mechanism Analysis; Mountain Region in the Upper Reaches of the Yangtze Basin
