摘要
近年来,黄河中游支流无定河流域水沙情势发生了显著变化,径流量与输沙量都出现了急剧减少的现象,其年径流量与输沙量序列变异类型(尤其是趋势变异、均值跳跃变异及方差变异)的信息重叠问题尚没有有效的解决方案,导致很难给出较为准确的变异归因解释。为此,以无定河流域10个水文站的实测年径流量和输沙量序列为研究对象,采用经验模态分解、STARS法和迭代累积平方和(ICSS)法对年输沙量序列进行趋势变异、均值跳跃变异和方差变异检验,识别无定河流域年输沙量序列变异的类型构成。同时,采用双累积曲线探讨无定河流域的水沙关系变化,并结合流域实际,分析变异类型产生的原因。结果表明:无定河流域年输沙量序列的变异类型均为复合类型,且复杂多变,其中趋势变异主要为先减后增型,均值跳跃变异为向上向下型和下沉型,方差变异主要为振幅缩减型;归因分析结果显示,无定河流域的淤地坝建设驱动年输沙量序列的下沉型均值跳跃变异,与其他水土保持措施一起驱动序列的趋势变异和方差变异;年降水量及沙尘暴频率因变化较小,仅在趋势变异上有微弱影响;淤地坝施工期间强降水引发的水土流失和淤地坝拦沙后清水下泄引发的河道冲刷驱动年输沙量序列均值向上的跳跃性变化,而淤地坝群淤积库容随时间的衰减则应该是驱动年输沙量序列趋势变异的关键因子。
In recent years, the runoff-sediment yield relationship in Wuding river basin, a branch of the middle Yellow River, changes dramatically, and the runoff and sediment discharge decrease sharply. There is no effective solution to propose for dealing with the overlap problem of the variation types of the annual runoff and sediment discharge sequences(especially the trend variation, the mean jumping variation and the variance variation), so that it is difficult to give an accurate attribution to the variations. Therefore, the observed annual runoff and sediment discharge sequences at 10 hydrological stations in Wuding river basin were taken as the research objects, by using empirical mode decomposition, STARS method and iterated cumulative sums of squares(ICSS) method;and the trend variation, the mean jumping variation and the variance variation of the observed annual sediment discharge sequences were tested, and the variation types of the annual sediment discharge sequence in Wuding river basin were identified. At the same time, the change of runoff-sediment yield relationship in Wuding river basin was explored by using the double cumulative curves, and the causes of the typical variation were analyzed by combining with the actual situation of the basin. The results show that the variation types of the annual sediment discharge sequence in Wuding river basin all belong to the compound types, which present the characteristics of complexity and changeability, therein, the trend variation mainly manifests as descending and then rising, the mean jumping variation shows the upward-downward change and sinking, and the variance variation is mainly the amplitude reduction;according to the results of attribution analysis, the warping dam construction in Wuding river basin drives the sinking mean jumping variation of the annual sediment discharge sequence, and leads to the trend variation and the variance variation of the sequence together with other water and soil conservation measures;the changes in precipitation and dust storm frequency have only a weak impact on the trend variation;the upward mean jumping variation detected in the compound types should be caused by the water and soil loss due to the heavy precipitation during the construction of the warping dam, and by river scour due to clear water discharge(including little sediment) after the dam;it should be noted that the decay of the storage capacity of the warping dam group for sediment deposition with time also contributes the trend variation of the annual sediment discharge sequence.
作者
张洪波
李娇娇
辛琛
李吉程
ZHANG Hong-bo;LI Jiao-jiao;XIN Chen;LI Ji-cheng(School of Environmental Science and Engineering,Chang'an University,Xi'an 710054,Shaanxi,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education,Chang'an University,Xi'an 710054,Shaanxi,China;Administration of Rivers and Reservoirs in Shaanxi Province,Xi'an 710018,Shaanxi,China)
出处
《地球科学与环境学报》
CAS
北大核心
2019年第2期241-252,共12页
Journal of Earth Sciences and Environment
基金
国家自然科学基金项目(51379014)
陕西省留学人员科技活动择优资助项目(2017035)
陕西省水利厅科技计划项目(2018slkj-11)
关键词
水文变异
输沙量
经验模态分解
STARS法
迭代累积平方和法
水沙情势
归因分析
无定河流域
hydrological variation
sediment discharge
empirical mode decomposition
STARS method
ICSS method
runoff-sediment yield relationship
attribution analysis
Wuding river basin
