DEVELOPMENT OF LARGE SCALED HYDROLOGICAL MODEL INCORPORATING THE TURBULENT ENRGY BALANCE IN THE SURFACE BOUNDARY LAYER

随着业务版本的推出，分布式水文模型有可能结合使用卫星遥感数据或雷达数据，提供非常高精度的高分辨率模型。发展高等级径流模式的问题是缺乏对地表边界层中的湍流输送及其在水文过程中的作用的了解。本研究试图在分布式水文模式中引入表层边界层力学进行初步研究，并对分布式模式在降雪融雪季节的发展进行研究。在研究的第一阶段，利用安装在吊车上的湍流计对风和温度的湍流脉动进行了现场观测。结果表明，风场和温度场的湍流特征以及动量和热量的湍流输送都得到了一定的结果。至于…的发展研究由于表层边界层机制在降雪-融雪季节中起着至关重要的作用，因此尝试将更多的分布式水文模式应用于降雪-融雪季节。在考虑降雪和融雪现象的过程中，降雪量是根据降水资料估算的，假定雨量计的捕获率和降雪量的高度相关性。采用热流法计算融雪量，并首次将该模型应用于有卫星遥感数据的乌诺河流域。从卫星数据中提取了流域的积雪面积，为利用径流模型再现积雪面积提供了可能。对于第二种应用，选择了上托内河流域，在这种情况下，流域内的温度分布是根据所获得的数据来确定的，该温度分布被输入到融雪计算、蒸发计算以及决定降雪的参数。计算结果表明，无论是流域出水口，还是流域内测点的径流量，都与实际情况相吻合。因此，温度递减率是一个重要的参数，它本质上是必须通过对地面边界层的分析来确定的气象参数。较少

The distributed hydrological model, with an operational version becoming available, bears a possibility of offering a very high-aceuracy high-resolution model with the combined use of the satellite remote sensing data or radar data. The problem in the development of a high-grade runoff model is the lack of knowledge of the turbulent transport in the surface boundary layer and its role on the hydrological processes. This study attempts to conduct a preliminary study on incorporating the mechanics of the surface boundary layer into the distributed hydrological model and developmental study of the distributed model to the snowfall-to-snowmelt season.At the first stage of this study the field observation of the turbulent fluctuation of the wind and temperature is carried out with the turbulent meters mounted on the craned vehicle. The result shows the turbulent characteristics of the wind and temperature and turbulent transport of momentum and heat is obtained.As for the developmental stud … More y of the distributed hydrological model, the application to the snowfall-to snowmelt season is attempted, as the surface boundary layer mechanics is crucial in this season. In attempting to include the snowfall and snowmelt phenomena, the snowfall amount is estimated from the precipitation data assuming the catch ratio of the rain gage and the altitudinal dependence of the snowfall. Snowmelt amount is calculated by the heat flux method.The model is first applied to the Uono River basin where the satellite remote sensing data is available. From the satellite data the snow covered area in the basin is extracted and this data offer the possibility of reproducing the snow covered area with the runoff model. For the second application the Upper Tone River basin is chosen, ln this case, temperature distribution in the basin, which is inputted to the snowmelt calculation, evaporation calculation as well as the parameter to decide snowfall, is decided from the data-obtained lapse rate. The calculation result shows agreement with the runoff discharge at not only the basin outlet but also gauged points within the basin. Temperature lapse rate thus is shown to be an important parameter which is essentially the meteorological parameter that has to be determined through the analysis of the surface boundary layer. Less