牛栏江—滇池补水工程水源区不同时间尺度径流变化特征

Characteristics of Runoff Changes at Different Time Scales in the Water Source Area of the Niulan River Dianchi Lake Replenishment Project

为做好补水工程水资源调度、配置、流域水安全治理和区域防汛抗旱工作,充分发挥工程效益,基于牛栏江—滇池补水工程水源区代表站长系列水文资料,采用集中度、不均匀系数、Hurst系数、M-K趋势检验、滑动T检验等多种方法分析了牛栏江—滇池补水工程水源区不同时间尺度径流变化特征。结果表明,水源区不同时间尺度径流年际变化大、丰-平-枯周期明显;年内分配向均匀性和坦化趋势演变;最小1、7 d径流显著上升,其他7个径流趋势变化不显著,均发生突变;年、丰水期、极端最大等5个径流指标突变后径流量减少明显,枯水期和极端最小等4个径流指标突变后为增长趋势;年径流突变后8~10月来水量减少明显;预计补水工程水源区未来一段时间不易发生极端枯水事件,但总来水量可能会进一步衰减。

In order to carry out water resource scheduling,allocation,watershed water safety management,and regional flood control and drought relief work in water replenishment projects,fully leveraging the engineering benefits,based on the representative station master's series of hydrological data from the water source area of the Niulan River Dianchi Lake Water Replenishment Project,the characteristics of runoff changes at different time scales in the water source area of the Niulan River Dianchi Lake replenishment project were analyzed using various methods such as concentration,non-uniformity coefficient,Hurst coefficient,M-K trend test,sliding T-test.The results show that the inter-annual variation of runoff at different time scales in the water source area is significant,with a clear period of high to low runoff;Evolution of distribution towards uniformity and normalization within the year;The minimum 1 d and 7 d runoff showed a significant upward trend,while the other 7 runoff trends showed no significant changes and all experienced sudden changes;After five sudden changes in runoff indicators,including the year,high water period,and extreme maximum,the runoff decreased significantly,while the four sudden changes in runoff indicators,including low water period and extreme minimum,showed an increasing trend;After the sudden change in annual runoff,the water inflow from August to October decreased significantly;It is expected that extreme low water events will not occur in the water source area of the water replenishment project in the future,but the total inflow may further decline.