摘要
建立了不均匀的地表径流算法,修改了RegCM2中径流方案,这一算法适用于疏松土壤和紧密土壤。设计了一个适合与气候模式RegCM2耦合、能模拟水文站流量的汇流模式。模拟了1998年夏季大暴雨期间6、7、8月降水的空间分布,分析了该径流方案对降水、地表热量通量、地表径流、土壤湿度产生的影响,结果表明:①本文提出的方案在模拟1998年长江流域夏季大暴雨期间降水的空间分布上有一定的合理性,在一定程度上改善了降水量的模拟,其影响大致是总降水量的10%左右。②地表径流方案改变了地面向大气输送的热量通量,这种作用随时间发生变化,这种变化与地表水分的再分配有关。③本方案计算的土壤渗透能力较强。在暴雨的初期,产生径流较少,而在暴雨后期土壤湿度增大,产生的地表径流较大,这一点更符合洪水形成的特点。
A hydrological model was designed to be coupled with RegCM2 and to simulate the discharges of the two important hydrological stations in the Yangtze River basin through adjusting the RegCM2 runoff scheme with the heterogeneous surface runoff algorithm that is suitable to both loosen and compact soil. The model was verified by observation data. The monthly precipitation of June, July and August 1998 during the rain storms was calculated with the model, and the impacts of the runoff scheme on precipitation, surface heat fluxes, runoff and soil moisture were analyzed. The results show that ① the runoff scheme is reasonable for simulating the precipitation distribution during the rain storms in 1998, and improved, to some extent, the precipitation simulation, about 10 % total precipitation;② the runoff scheme changes, from time to time, the heat fluxes from surface to atmosphere, which is related to the re-assignment of surface water;③ this scheme enhances soil infiltration which results in less runoff during the early period of the rainstorm, and more runoff during the late period.
出处
《气象科技》
2005年第5期394-400,407,共8页
Meteorological Science and Technology
基金
国家重点基础研究项目(2001CB309404)
国家自然科学基金海外杰出青年合作项目(40128001/D05
49375248)
江苏省科研项目(2004C33082)资助
