基于变结构协整理论的水沙关系研究

Study on Relationship of Runoff and Sediment Load Based on Variable Structure Cointegration Theory

为了合理掌握黄河上游径流—泥沙关系,以贵德水文站年径流和年泥沙作为研究数据,利用累积距平法对突变点进行分析,在此基础上分别在不考虑、考虑结构突变的情况下,构建相对应的协整模型和误差修正模型,并评价了模型精度。结果表明,由于水库构建径流量和输沙量存在明显的突变点,在不考虑结构突变的情况下水沙序列的协整关系较弱;考虑结构突变后对应的协整关系性显著提高,特别是模型3对径流量模拟的年平均相对误差最小,为8.31%,该模型充分考虑了时间序列的非均衡误差和突变信息,能更准确地反映径流量与输沙量之间的长期均衡关系与短期波动特征。

To understand the runoff-sediment load relationship in the upper reaches of the Yellow River,the annual runoff and sediment load of Guide Hydrological Station were taken as the research data.Based on the analysis of the catastrophe point by using the cumulative anomaly method,the corresponding cointegration model and error correction model were constructed with or without considering the structural breaks,and the model accuracy was evaluated.The results show that the cointegration relationship between runoff and sediment load is weak without considering the structural break,because of the obvious abrupt transition point of runoff and sediment load in reservoir construction.The corresponding cointegration relationship is significantly improved after the structural break is taken into account.In particular,the annual average relative error of the runoff simulation of Model 3 is the smallest,which is 8.31%.This model fully takes into account the unbalanced error and break information of the time series,which can more accurately reflects the long-term equilibrium and short-term fluctuation relationship between runoff and sediment load.