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流域出口径流观测序列是水文模型参数率定重要依据,不受水文站控制区域的模型应用是水文研究关注点之一。首先根据水文站观测资料建立洞庭湖流域四水控制站之上基于水文响应单元的分布式水文模型,在此基础上结合实验、同质移植和虚拟水库等方法,将分布式水文模型拓展到包含无径流站控制区域的丘陵区间和平原圩垸区,最终实现了洞庭湖全流域水文过程模拟。结果表明:在较完备土壤、地形、土地利用等空间数据支持下,通过合理的流域划分和水文响应单元定义,建立的流域分布式水文模型可以较好地在水文响应单元尺度反应降水发生后蒸散、地表径流、土壤和地下水的响应特征。而基于观测实验及基流分割等方法获取的关键水文过程特征对模型参数优化的认识,可以提高模型参数率定效率,在较少优化迭代运算后既可使月径流模拟的效率系数NSE和确定性系数R2值高于0.81(日过程高于0.62)。借助参数同质移植和虚拟水库解决了区间和圩垸区无控制站区域水文过程模拟。在全流域水文过程的模拟中,基流指数和蒸散比例与实际过程具有较好的一致性。说明相关参数较好地反映了其物理机制,具备在相似气候及下垫面条件区域进行同质移植的基础,圩垸区径流交换采用虚拟水库的处理方式也合理可行。
Watershed exit runoff observation sequence is an important basis for the hydrological model parameter calibration, and it is one of the focus of hydrological research that the model application from the control area of hydrological station is not applied. Firstly, a distributed hydrological model based on hydrological response units above the four water control stations in the Dongting Lake Basin was established based on observation data from hydrological stations. On the basis of this, combined with experiments, homogenous transplantation and virtual reservoirs, the distributed hydrological model was expanded to include No runoff station control area hilly area and plain embankment area, and ultimately achieve the hydrological process simulation of the whole basin of Dongting Lake. The results show that under the support of spatial data such as more complete soil, topography and land use, the watershed distributed hydrological model established by rational watershed division and hydrological response unit can evaporate well after the precipitation of hydrological response unit scale precipitation , Surface runoff, response characteristics of soil and groundwater. The recognition of model parameter optimization based on the key hydrological process characteristics obtained by observational experiments and base-flow segmentation can improve the efficiency of model parameter calibration. After less optimization of iterative computing, both the efficiency of runoff simulation NSE and the determination of The R2 of the sex coefficient is higher than 0.81 (the daily course is higher than 0.62). With the help of parameter homogenous transplantation and virtual reservoir, the hydrological process simulation in the area without control stations in the interval and the embankment area was solved. In the simulation of hydrological processes in the whole basin, the base flow index and evapotranspiration ratio are in good agreement with the actual process. It shows that the relevant parameters reflect its physical mechanism better and have the basis of homogeneous transplantation in similar climate and underlying surface conditions. It is also reasonable and feasible to adopt a virtual reservoir for the runoff exchange in the embankment.