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

分布式水文模型随着可操作版本的出现，有可能结合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。开发高级别径流模型的问题是缺乏对地表边界层湍流输送及其在水文过程中的作用的认识。本研究试图对将地表边界层力学纳入分布式水文模型进行初步研究，并对分布式模型对降雪-融雪季节的发展进行研究。在本研究的第一阶段，利用安装在起重机上的湍流仪对风和温度的湍流波动进行了现场观测。结果表明，得到了风和温度的湍流特性以及动量和热量的湍流输运。对于分布式水文模型的发展问题，尝试将其应用于降雪-融雪季节，因为在这个季节，地表边界层力学是至关重要的。在尝试包括降雪和融雪现象时，假设雨量计的捕获比和降雪的高度依赖性，从降水资料估计降雪量。融雪量采用热通量法计算。该模型首先应用于有卫星遥感数据的乌诺河流域。从卫星数据中提取流域积雪面积，该数据为径流模型再现积雪面积提供了可能。第二次应用选择上Tone河流域，在这种情况下，流域内的温度分布由数据获取的递减率决定，并输入到融雪计算、蒸发计算以及决定降雪量的参数中。计算结果不仅与流域出水口径流量吻合，而且与流域内各测量点径流量吻合。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。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