【作者】 李楠；

【导师】 胡彩虹； 岳利军；

【作者基本信息】 郑州大学 ， 水利工程， 2018， 硕士

【摘要】 20世纪70年代以来,黄土高原地区水循环过程和水资源情势发生了显著改变。而黄土高原水文特征变化事关整个黄河流域的洪涝灾害防治、水资源配置及水生态保护等民生与环境问题。且随着水土保持措施的实施及“退田还林、封山绿化”等方针的落实,黄土高原大部分地区的植被覆盖变化十分显著。因此在植被覆盖、下垫面特征不断变化的条件下,黄土高原产汇流机制是否发生变化就成为了需要深入研究的问题。本文在“十三五”国家科技支撑计划项目“黄河流域水沙变化机理与趋势预测”(2016YFC040240203)的支撑下,选择有代表性的汾河上游静乐站控制流域及祖厉河流域为典型研究对象,对黄土高原地区场次洪水的产汇流模式进行辨析,并探索随着流域下垫面的不断变化,流域产汇流机制是否发生变化,为其它地区的相关研究提供参考。研究的主要内容及结论如下:(1)黄土高原下垫面条件变化特征分析在收集整理黄土高原地区水文气象数据、土地利用与人类活动相关数据的基础上,结合前人所做的研究对黄土高原下垫面条件变化特征进行总结分析。结果表明,近40年黄土高原地区下垫面变化明显,具体表现在植被、淤地坝、水库及梯田等方面。(2)典型流域下垫面及暴雨洪水特征分析选择汾河上游静乐站控制断面以上流域及祖厉河流域作为典型流域进行研究,首先根据典型流域不同时期遥感影像资料,解译分析流域下垫面变化特征,然后依据场次降雨洪水过程数据,计算暴雨洪水特征值并分析其特性。(3)典型流域产汇流机制分析在降雨径流特征分析的基础上,对场次降雨洪水产流模式及汇流特点进行辨识。研究发现静乐站控制流域场次洪水径流成分发生变化,且超渗产流发生的比例减小,混合及蓄满产流发生的比例增加。祖厉河流域仍以超渗产流为主要产流方式,结合以往研究及下垫面分析发现下垫面变化未导致祖厉河流域产汇流机制发生较大变化。(4)典型流域产汇流机制变化年份及其原因分析运用双累积曲线及产汇流特征值变化趋势分析发现1998年后静乐站控制流域产汇流机制变化明显,其中洪水产流量减少约43%,径流系数减小50%,洪峰流量减少约40%,洪峰滞时增大21.9%。分析发现森林覆盖度增加,导致流域地下水出流能力、地面下渗能力及流域蓄水能力增强,从而导致产汇流特征的变化。更多还原

【Abstract】 Since the 1970 s,water circulation processes and water resources conditions have changed significantly in the Loess Plateau.The changes in the hydrological characteristics of the Loess Plateau affect the people’s livelihood and environmental issues such as flood control,water resources allocation and water ecological protection in the Yellow River Basin.With the implementation of soil and water conservation measures and the implementation of the guidelines of “Returning farmland to forests”,the vegetation coverage in most parts of the Loess Plateau has recovered significantly.Therefore,under the background of vegetation cover and underlying surface characteristics recovered significantly,whether the mechanism of flow production and convergence in the Loess Plateau has changed has become an issue that needs to be studied in depth.This paper is under the support of the “Thirteenth Five-Year Plan” National Science and Technology Support Plan“Mechanism and Trends of Water and Sediment Changes in the Yellow River Basin”.The Jingle Station Control Basin in the upstream of Fenhe River and Zuli River Basin are selected as typical research areas,analyzed the patterns of production and confluence of flood in the Loess Plateau region,And explored whether the mechanism of runoff production and confluence changed with the change of underlying surface,and provide reference for relevant research in other regions.The main research contents and results of this paper are as follows:(1)Analysis of Characteristics of Underlying Surface Condition in the Loess Plateau.On the basis of collecting data on the hydro-meteorological data,land use and human activities in the Loess Plateau,and combining previous studies,the characteristics of the underlying surface of the Loess Plateau were analyzed.The results show that the underlying surface of the Loess Plateau has changed significantly in the past 40 years,which is reflected in changes in vegetation,silt dams,reservoirs,terraces and so on.(2)Analysis on Characteristics of Underlying Surface and Runoff in Typical Basins.Jingle Station Control Basin in the upstream of Fenhe River and Zuli River Basin are selected as as typical basins for research.First,remote sensing data at different periods in a typical watershed are interpreted and the characteristics of the underlying surface of the basin are analyzed.Then according to the data of rainfall flood process,calculated the characteristics of storm floods and analyzed their characteristics.(3)Analysis of runoff Production and Confluence Mechanisms in Typical Basins.On the basis of the analysis of rainfall and runoff characteristics,the runoff production patterns and confluence characteristics were identified.The study found that the composition of runoff changes in Jingle Station Control Basin,and the proportion of infiltration-excess runoff decreases,and the proportion of saturation-excess runoff increases.The Zuli River Basin is still dominated by infiltration-excess runoff,based on previous studies and analysis of underlying surface,it has been found that changes in the underlying surface have not resulted in major changes in the runoff production and confluence mechanism of the Zuli River Basin.(4)Analysis on the Changing Years and Causes of Runoff Production and Confluence Mechanisms in Typical River Basins.According to the double-accumulation curve and the eigenvalues trendency of runoff production and confluence,it was found that after 1998,the mechanism of the production and confluence of Jingle Station Control Basin changed significantly.And the flood volume is reduced by about 43%,the runoff coefficient is reduced by 50%,the peak flow rate is reduced by about 40%,and the flood peak delay is increased by 21.9%.It was found that due to the increase of forest coverage,groundwater discharge capacity,ground infiltration capacity,and water storage capacity in the river basin were increased,resulting in the changes of runoff production and confluence characteristics.更多还原