地貌瞬时单位线在江西省无资料地区洪水预报的适用性研究

Applicability of geomorphic instantaneous unit line in flood forecast in Jiangxi area without data

本文选取吉安南车水库流域为研究区域,基于吉安南车水库流域的原始地形高程,运用GIS技术提取流域内的三级河流,并得到模型所需的流域参数和地貌单位线。通过编程简化了计算过程,便于不同流域中重复使用,也为流域信息化集成提供了基础,计算得到的地貌单位线嵌入江西省吉安市水库防汛调度预报系统,完成了场次洪水预报。研究结果表明:对南车水库流域确定的6场洪水过程进行模拟统计,采用地貌单位线进行流域汇流计算,模拟结果洪量、洪峰、峰现时间的平均相对误差分别为17%、19%和3h,综合预报合格率50%。

In this paper,CSR Reservoir basin in Ji’an is selected as the study area.Based on the original topographic elevation of CSR Reservoir basin in Ji’an,the third-class rivers in the basin are extracted by GIS technology,and the basin parameters and geomorphic unit lines required by the model are obtained.The calculation process is simplified by programming,which is convenient for reuse in different watersheds,and also provides a basis for watershed information integration.The calculated geomorphic unit line is embedded in the reservior control dispatching and forecasting system of in Ji’an in Jiangxi Province,and the flood forecasting is completed.The results show that,according to the six flood processes identified in CSR Reservoir basin,simulation statistics are carried out,and watershed confluence calculation is carried out by using geomorphic unit line.The average relative error levels of flood volume,flood peak and peak occurrence time are 17%,19%and 3h respectively,and the qualified rate of comprehensive forecast is 50%.