论文部分内容阅读
采用Mann-Kendall统计检验方法和Pettitt系列显著性突变点的无参数识别方法分析延河流域径流和泥沙演变趋势及突变点,基于流量历时曲线分析延河流域突变点前后径流和泥沙变化特征,研究了水土保持措施对流域径流和泥沙的影响。结果表明:延河流域径流和输沙量均呈减少趋势,输沙量在1971和1996年有2个显著性的突变点,对于黄土高原丘陵沟壑区,水土保持措施减少河川径流量和输沙量。随着突变点后期水土保持措施力度的加大,水土保持措施拦蓄径流和泥沙的作用逐渐增强。水土保持措施使径流高流量部分减少,常流量和低流量部分增加,表明水土保持措施可削减汛期流量,增补枯季流量。突变点后期输沙量较之变化前期整体呈减少趋势。研究结果可为黄土高原丘陵沟壑区的水土保持和水资源管理工作提供一定参考。
Using Mann-Kendall statistical test method and Pettitt series significant mutation point no-parameter identification method to analyze the trend and the change point of runoff and sediment evolution in Yanhe River Basin, and to analyze the characteristics of runoff and sediment change before and after the sudden change point in Yanhe River Basin based on the flow duration curve , Studied the impact of soil and water conservation measures on runoff and sedimentation in the basin. The results showed that the runoff and sediment transport in Yanhe River Basin showed a decreasing trend. There were two significant abrupt changes in sediment load in 1971 and 1996. For the hilly and gully regions in the Loess Plateau, water and soil conservation measures to reduce runoff and sediment transport the amount. With the intensification of soil and water conservation measures in the later period of abrupt change, the role of water and soil conservation measures to intercept runoff and sediment gradually increased. Soil and water conservation measures reduced part of the runoff from high and part of the regular and low flows, indicating that soil and water conservation measures can reduce the flood season flow and increase the dry season flow. The amount of sediment transport at the late stage of change is decreasing compared with that at the early stage of change. The results can provide reference for soil and water conservation and water resources management in the hilly and gully regions of the Loess Plateau.