基于水文模型的流域蒸散发规律

基于双源蒸散发模型与栅格产汇流模型，该文构建了分布式流域水文模型，在老哈河上游的甸子流域模拟了蒸散量的时空变化过程。研究结果表明：相比蒸发皿观测数据计算的蒸散发能力，双源模型计算实际蒸散量作为水文模型的驱动因子更具优势，其能够有效地模拟流域尺度实际蒸散量的变化过程；不同植被类型的截留蒸发、植物蒸腾、蒸散量过程都呈单峰形式，夏季达到最大值，高大植被的植被蒸腾量和生产性蒸发比例显著高于低矮植被；不同植被条件下的土壤散发变化规律不一致，高大植被在5月达到峰值，低矮植被则在6月或7月达到峰值。

Estimaton of evapotranspiration in catchment based on distributed watershed hydrological model

The distributed hydrological model including dual-source evapotranspiration moduleand runoff-yield module based on grid excess saturation scheme was established for simulating the evapotranspiration process of temporal and spatial variance was estimated in Dianzi basin, headwater region of Laoha River. The modeling result confirmed that the dual-source model could effectively simulate the actual evapotranspiration process in catchment scale and well support the distributed hydrological modeling rather than the potential evapotranspiration estimated by the pan measurement. The temporal variance of nterception evaporation, plant transpiration and evapotranspiration for different vegetations was similar, with the peak value in summer. Tall vegetation transpiration and proportion of productive evaporation was significantly higher than that of low vegetation. However, the temporal variance of evapotranspiration for soils covered for different vegetations was heterogeneous; the peak value of tall vegetations was in May and the peak value of short vegetations was in June or July.