三峡工程大江截流水文气象预报

Hydrometeorological forecast for TGP's main river closure

为保障三峡工程大江截流期施工的顺利进行 ,长江委水文局于 1997年 4月 15日起开展了三峡截流施工期长、中、短期水文气象预报工作。预报处通过对卫星云图、测雨雷达、常规气象资料跟踪监测分析及数值预报产品的分析 ,完成了 12、2 4、48h定量降水预报。三峡截流期间 ,根据中期 3～ 7d定量降水预报 ,完成了三峡坝址未来 5～10d的日平均流量滚动预报。长期水文气象预报主要是通过对天气气候背景、大气及海洋环流特征、天文因素、地球物理因子进行定性分析 ,运用统计方法 ,做出一个月至一年的降雨分布及水情趋势预测。在三峡施工截流过程中 ,长江委水文局发布的长、中、短期水文气象滚动预报 ,使截流施工的指挥者对来水情况、导流情况的变化趋势做到心中有数 ,对于保证截流胜利成功起到了积极作用。

Hydrological Bureau of Changjiang Water Resources Commission carried out long,middle and short term hydrometeorological forecast during TGP river closure construction.Through successive monitoring and analysis of satellite cloud picture,rain detection radar data and conventional meteorological data as well as analysis of numerical weather prediction results,the quantitative precipitations of 12,24,48 h were forecasted.According to 3～7 d quantitative precipitation prediction in middle term,the coming 5～10 d successive mean daily discharges at TGP dam site were forecasted.Long-term hydrological and meteorological forecast was carried out through qualitative analysis on climatic background,characteristics of atmosphere and ocean circulation,astronomic factor and geophysical factor by means of statistical analysis to predict precipitation distribution and water regime trend from one month to one year.In the process of TGP river closure construction,the long,middle and short term successive hydrological and meteorological prediction issued by Hydrological Bureau of CWRC made the command post of river closure construction know fairly well the variation trend of river flow,diversion condition and played important role in successful river closure.