缺资料地区日降雨时间上向下尺度化方法探讨——以黄河流域为例  

Temporal Downscaling Daily Precipitation in Lack-Data Watershed——A Case Study in Yellow River

作　　者：周祖昊[1] 王浩[1] 贾仰文[1] 罗翔宇[1] 王建华[1] 

机构地区：[1]中国水利水电科学研究院水资源研究所,北京100044

出　　处：《资源科学》2005年第1期92-96,共5页Resources Science

基　　金：国家重点基础研究发展规划项目(编号:G1999043602);黄委会"十五"治黄重大科技项目(编号:2002Z02)。

摘　　要：降雨是流域水循环的主要影响因子之一,雨强时程分布对于流域水循环具有重要的意义,在相同的下垫面条件下,如果降雨强度不同,产流机制也会出现很大的不同。然而,要想获得完整长系列的短历时降雨资料,难度很大。本文以黄河流域为例,提出了日降雨时间上向下尺度化模型,探讨了缺资料地区通过日雨量在时间上向下尺度化生成短历时降雨资料的方法。文中根据黄河流域降雨特点,把全流域分成5个降雨区划,采用1991年～1997年731个站点大于10mm雨日的短历时降雨记录,对向下尺度化模型的参数进行了分区率定和分析。通过分析实测短历时降雨资料发现,黄河流域日降雨量和历时相关关系很差,相比而言,与雨强相关关系较好。文中建立了1个日雨量～雨力关系模型,并分区率定了模型的参数。日降雨时间上向下尺度化模型的参数反映了雨强日内分布的集中程度,大体趋势是从西到东增强的。本文采用Nash Sutcliffe效率系数和MSEQ两种指标对模型进行了评估,分区统计结果显示,提出的模型和方法是有效的,下一步的工作是在流域水文模拟中进行应用和作进一步地验证。The precipitation is one of the main factors involved with river basin water cycle. The temporal distribution of rain is significant to water cycle. If the intensity of rain is different, the mechanism of runoff may be different in the same underlying surface. However, it is hard to collect the complete long series short duration precipitation data. The model of temporal downscaling of daily rain is presented with Yellow River as a case in this paper. And the approach of temporal downscaling of daily rain to acquire short-term rain data in lack-data watershed is studied as well. According to the distributing characteristics of the rain in Yellow River, the basin is divided to five sections. Using the short-time data of the 731 rain gauges observed in 1991～1997 whose daily rainfall is more than 10 mm, the parameters of the temporal downscaling model are calibrated and analyzed for respective sections. It is shown by analyzing the observed data that the correlativity between daily rainfall and the duration of precipitation is not good but that between daily rainfall and the rain force is comparatively satisfactory. So a daily rainfall - rain force model is presented in this paper and its parameters are identified. By analyzing the parameters of the temporal downscaling model we can find out that the rain intensity during a day has a trend to be more uneven from west to east. The two indices of Nash-Sutcliffe coefficient and MSEQ are used to validate the model. As a contrast, MSEQ values of equably distributing the daily rainfall in a day are calculated. The temporal downscaling model's average of the both indices in different sections shows that the model is effective. The next task is to apply the model presented in this paper in hydrological simulation. At the same time, the model will be tested in application further more.

关 键 词：日降雨量 日雨量 黄河流域 尺度 分布 区划 雨强 长系列 雨日 水循环 

分 类 号：P426.613[天文地球—大气科学及气象学]