【作者】 韩瑞光；

【导师】 冯平；

【作者基本信息】 天津大学 ， 水文学及水资源， 2010， 博士

【摘要】 近年来海河流域下垫面情况发生了显著变化,并对年径流及洪水产生明显影响。通过选取流域内大清河山区作为典型区,利用数理统计和模型分析方法,揭示了下垫面变化对洪水径流的影响。主要成果表述如下:(1)典型区暴雨洪水变化趋势分析:利用Kendall非参数秩次相关检验法、线性滑动平均法和回归分析法,分析了海河流域紫荆关、阜平、龙门等典型区汛期暴雨变化趋势、洪峰流量及次洪量变化趋势。在降雨变化不明显的情况下,历年次洪量、洪峰均有下降趋势,其中紫荆关站典型洪水的次洪量具有明显的下降趋势。(2)山丘区产汇流参数变化趋势分析:对流域最大蓄水容量(Im)、流域水面蒸发和流域蒸散发量、流域土壤含水量消退系数(K)等产流参数,洪水滞时、单位线等汇流参数进行了趋势分析和流域代表区降雨径流的相关分析。人类活动影响使得大清河山丘区的土层最大蓄水容量在1980年以后有所增大;水面蒸发总量呈减小的趋势,年蒸散发总量与降水量成正比关系,其年际变化不明显。土壤消退系数呈增大趋势,但幅度一般在2%—5%之间;20世纪80年代后洪水滞时比80年代前长,但随着降雨强度的增大,80年代后洪水滞时与80年代前相差变小。(3)河北山区雨洪模型建立及典型站洪水系列下垫面修正利用山区雨洪模型分别对1980年前后的降雨径流系列率定产汇流参数,根据两组参数的变化来反映下垫面的变化;利用1980年以后产汇流参数重演1980年前典型洪水,通过模拟值之差反映流域下垫面变化对洪水的影响。模拟结果表明,大清河水系典型区的下垫面变化对大洪水的洪峰和洪量影响的小,对中小洪水的洪峰和洪量影响较大。(4)土地利用/覆被变化的集总式流域水文模型的建立和下垫面影响分析为了定量评估土地利用/覆被变化对洪水的影响,本文建立了考虑土地利用/覆被变化的集总式流域水文模型。经参数率定和模型验证,模拟流量过程与实测流量过程拟合较好。运用该水文模型,对研究区域的洪水采用历史反演法,以1980年下垫面参数为基础,选取90年代后洪水进行模拟;以2004年下垫面参数为基础,选取80年代前洪水进行模拟,揭示不同土地利用覆被情况下对同场降雨过程的洪水响应。更多还原

【Abstract】 The conditions of the underlayer in Haihe River Basin has changed dramatically during the past few years, which affected annual runoff and flood peaks and volumes. Due to the complexity of hydrological phenomenon, the paper mainly employed mathematical statistics method, the theory of stochastic hydrology and hydrological model to describe hydrological phenomenon and to analyze storm flood characteristics quantitatively in Daqing river basin. The main results are as follows:(1) The Mann-Kendall trend test, moving average method, and regression analysis method are employed to analyze the trends of rainfall amount, flood peaks and flood volumes in Zijingguan, Fuping and Longmen sub-catchment. It is shown that there is no obvious trend for rainfall amount, while flood volumes and peaks are decreased, especially in Zijingguan sub-catchment.(2) The trends of maximum soil moisture capacity(Im), water evaporation and basin evapotranspiration, the regression coefficient of soil moisture, the lag time of flood peak, and unit hydrograph are analyzed, and the relationship of rainfall and runoff is studied as well. The results show that the maximum soil moisture content increased after 1980 due to human activities. Water evaporation decreased, and the regression coefficient of soil moisture shows a increasing trend which varies between 2~5%. The lag time of flood peak increased after 1980, however, the variation is limited if rainfall intensity is large enough.(3) A hydrological model is established and the parameters in the model are calibrated using the hydrological data before and after 1980 respectively, which can reflect the sublayer changes. The parameters calibrated by hydrological data after 1980 are used for input to simulate the flood before 1980 , thereby, the difference between the simulated flood volume and peak are considered to be the influence of sublayer changes. The modelled results indicate that the sublayer changes have a small effect on large floods and a large effect on small floods.(4) A hydrological model considering land use/land cover change is established to assess the effect of land use change on flood quantitatively. The model can simulate flood processes well. So The flood processes after 1980 were simulated based on parameters of 1980; and flood processes before 1980 were simulated based on land surface parameters of 2004. It is used to analyze the impacts of different land use and land cover on flood with the same rainfall process, especially to study the changes of LUCC impacts on peak flow and flood volume.更多还原