牛栏江中上段枯季径流分析及月径流模拟

为分析牛栏江中上段中长期径流特征,基于牛栏江中上段七星桥水文站1990～2016年降水、蒸发、径流实测资料,使用一元线性回归、退水系数、离散系数等分析了牛栏江枯季径流特点及趋势。结果表明,牛栏江中上段枯季径流量、降水量无明显变化趋势,但蒸发量有明显减少趋势,枯季径流量占年度径流量的比例有增加趋势,11月至次年4月,月径流量逐步大幅减少,但趋势分析表明,11月径流量有明显减少趋势,12月无明显变化趋势,1～4月径流量呈增加趋势,枯季各月径流量总体趋向于均衡。使用Pearson相关分析法识别枯季月径流预报因子,基于二次回归正交旋转设计,构建了枯季各月预报模型,模型模拟检验表明,11月径流预报模型精度为丙级,12月至次年4月径流预报模型精度为乙级。研究成果可为牛栏江—滇池补水工程枯季水资源调度提供依据。

Analysis of Dry Season Runoff in the Middle and Upper Reaches of Niulanjiang River and Simulation of Monthly Runoff

Based on the 1990-2016 precipitation, evaporation and runoff data from the Qixingqiao Hydrological Station in the upper and middle sections of the Niulan River, this study analyzed the characteristics and trends of the runoff in the Niulan River during the dry season by using linear regression, water withdrawal coefficient and dispersion coefficient. The results show that the runoff and precipitation of the upper middle section of the Niulan River have no obvious change trend, but the evaporation has a significant decrease trend. The dry season runoff accounted for a trend increase in the annual runoff ratio. From November to April in the next year, the monthly runoff decreased gradually, but the trend analysis showed that the runoff in November appeared a downward trend, and there was no obvious change trend in December. The runoff in January, February, March and April showed an upward trend, and the average runoff in each month of the dry season tended to be balanced. The pearson correlation analysis method was used to identify the monthly runoff forecasting factors in the dry season. Based on the quadratic regression orthogonal rotation design, the monthly forecast model of the dry season was constructed. The model simulation test shows that the accuracy of the runoff forecast model in November is C, and the accuracy of the runoff forecast model during December to April in the next year is Grade B. The research results can provide basis for water resources allocation in the dry season in the Niulanjiang-Dianchi water supply projects.