地形地貌对小流域产汇流过程的影响研究

Prediction of flash flood in small watershed has been a hotspot but also a difficult issue in present hydrology and water resource research. As hillslopes take high proportion in small watersheds and most of which belong to ungauged area, slight change in geomorphology will contribute great influence to the occurrence and confluence of slope runoff. This research builds on the combination of indoor physical model experiments and outdoor observation of natural watershed. The influence to hillslope runoff occurrence from micro-topography was probed through intensifying the observation of genesis and progression of precipitation, surface water, interflow and underground water under complex topographic condition. The computational formula of slope flow was built on the basis of the unite of theoretical analysis and physical model, and used collected filed water samples for isotope analysis to discuss the propagator of slope sluggish at the same time. So can we come up with a new generation geomorphologic instantaneous unit hydrograph with slope confluence process was considered. And then a distributed hydrological model for small watershed adapting to specific scale was built. Scientific theoretical foundation from these research results can be provided for the solution of flood prediction in medium and small watersheds in China.

小流域暴雨洪水预测是当前水文水资源研究的热点和难点问题。小流域中坡地所占比例极大且多属于无资料地区，地形地貌的些微变化对坡地的产汇流过程都会带来极大影响。本申请项目拟以室内物理模型实验结合野外天然流域现地观测为基础，通过强化观测复杂地形条件下降水、地表水、壤中径流及地下水的发生发展过程，探讨微地形对山坡产流过程的影响；在理论分析结合物理模型基础上建立坡面水流计算公式，同时采集野外水样进行同位素分析，探讨坡地滞时分布函数，并由此构建能够考虑坡地汇流过程的新一代地貌瞬时单位线；最终构建一个具有一定尺度适应性的小流域分布式水文模型。研究成果可为解决我国中小河流的洪水预报问题提供科学的理论依据。

小流域暴雨洪水预测是当前水文水资源研究的热点和难点问题。小流域中坡地所占比例极大且多属于无资料地区，地形地貌的些微变化对坡地的产汇流过程都会带来极大影响。本研究项目以室内物理模型实验为基础，通过强化观测不同微地形条件下降水、地表水、壤中径流及地下水的发生发展过程，探讨微地形对山坡产汇流过程的影响，在理论分析结合物理模型基础上建立坡面水流计算公式；探讨坡地滞时分布函数，同时解决传统地貌单位线中往往回避的关于流域平均流速的确定方法，构建能够考虑坡地汇流过程的新一代地貌瞬时单位线；最后尝试探讨了流域尺度下垫面变化对设计洪水的影响过程。在完成拟定的各项研究任务基础上，课题组分析了坡度、坡向及雨强等对产汇流过程的影响程度；提出了一种确定地貌瞬时单位线中水动力参数的定量计算新方法；提出了与尺度无关的新型地貌瞬时单位线；最终将上述研究成果在江苏省无资料小流域产汇流模型研制及江苏省水文手册修编工作中进行推广应用。共发表学术论文28篇，其中SCI论文11篇；申请专利9项，获授权发明专利1项；培养硕士研究生10名，博士研究生1名。