基于水文倒推法的中小洪水过程模拟

为了改善传统的中小洪水模拟方法中对洪水过程模拟精度较低的问题，用水文倒推法对研究区域出口断面的流量过程进行模拟。鉴于流域枯季径流缓慢变化的特点，基于水量平衡方程，对时段平均的径流量与径流变化量的相关关系进行推导，建立了基于水文倒推法的中小洪水模拟方程，并推出方程的适用范围。通过清江流域1989—1995年的场次洪水过程模拟，结果表明:洪水过程模拟效果较好，涨水和退水趋势与实测流量基本无差异，退水过程的拟合程度优于涨水过程；模拟洪峰精度符合要求。与传统洪水模拟方法和枯季径流预报方法相比，该方法计算简单，并能以过程线的方式描述中小洪水的洪峰量级，为水库调度提供科学的决策依据。

Simulation of small and medium-scale floods by doing hydrology backwards

In order to improve the precision of the simulation of small and medium-scale floods when using traditional methods, we used a method of doing hydrology backwards to simulate the flow at the outlet cross-section of the study area. Based on the characteristics of slowly-varying low flow in the study basin, we deduced the relationship between the average runoff of a period and the changing rate of the average runoff using the water balance equation, established an equation for the simulation of small and medium-scale floods based on doing hydrology backwards, and deduced the application range of the equation. The simulation of floods over the Qingjiang River Basin during the period from 1989 to 1995 showed that the simulated rising and recession trends agreed with observed data, the recession curves were better fitted than the rising curves, and the precision of the simulation of flood peaks met the requirements. Compared with traditional flood simulation methods and low-flow forecasting methods, the proposed method can be easily used for calculation and can describe the magnitude of peak flows of small and medium-scale floods using flood hydrographs, providing a scientific decision-making basis for reservoir operation.