【作者】 刘鹏举；

【导师】 朱金兆；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2007， 博士

【摘要】 分布式水文模型的出现为森林植被水文生态效益的多尺度评价与尺度转换提供新的思路,成为当前水文生态学研究的热点。然而单个尺度的水文过程模拟已经难于满足我们对于水文过程多尺度特性以及不同尺度水文过程关系研究的要求。流域作为陆地水文循环的基本单元,具有明确的边界,是水文过程研究与水资源管理的基础。嵌套流域是自然界地形地貌层次结构的体现,是研究水文过程尺度转换的天然实验场。本论文以流域水文学理论、DDDAS、尺度理论为指导,提出多尺度分布式水文过程模拟研究框架,解决基于GIS的多尺度地表径流模型模拟关键技术问题,为通过模型进行嵌套流域水文尺度变化规律与尺度转换研究提供支持。主要研究成果如下:(1)基于DEM的地形地貌分析技术,提出多尺度分布式水文生态过程模拟框架。该框架支持不同基本单元模型的水文过程研究与测试,为各尺度过程模型模拟提供试验平台;支持不同尺度模型间的相互嵌套与验证,为嵌套流域水文过程尺度转换研究提供支撑;支持多尺度分布式水文模型与多尺度调查监测数据的交互,为流域水文过程机理探索与应用决策提供支撑。(2)通过研究地形地貌分割技术,形成了流域地貌的多级分割技术体系。以数学形态学技术为基础,提出了基于数字化等高线生成保持地貌特征的数字高程模型生成技术。通过研究基于DEM的河网提取技术,形成了多级流域自动划分方法。基于DEM与水流路径对沟缘线提取技术进行了研究,提出了有效的解决方案。通过以上技术研究,形成了基于DEM的栅格单元、坡面、集水区、嵌套流域多级地貌单元自动生成技术。(3)建立了多尺度地貌基本单元提取与参数自动生成系统。在地貌单元自动提取的基础上,对单元参数的自动生技术进行了研究,形成了多尺度地貌单元参数生成系统。以晋西黄土区蔡家川嵌套流域地形数据为基础,进行了多尺度地形参数分析,得到了流域地貌特征的多尺度变异规律。(4)以DDDAS范式为指导,研究了多尺度动态分布式水文生态模型建构技术,建立了地表径流模拟系统。该系统与多尺度地貌单元参数自动生成系统结合,能够支持多尺度流域地表径流模拟过程,支持多种尺度单元水文模型的耦合,为进行多尺度水文过程模拟与尺度辨析、尺度转换提供支撑平台。(5)应用建立的系统,对蔡家川嵌套流域地形地貌进行了处理与分析,并进行了暴雨地表径流模拟。结果表明该模型能够有效区分不同降雨模式对水文过程的影响,并且能够进行嵌套流域多尺度水文过程的模拟,可以为流域水文过程及相互关系研究、尺度转换提供平台,为森林植被对区域农业水土资源调控范围和强度问题提供理论与方法。更多还原

【Abstract】 Distributed hydrological model becomes a focus of ecology hydrological research because it provides insights to solve the problems of multi-scale evaluation and upscaling of hydrological benefits of forest. However distributed hydrological model confront with some new challenges, hydrological process simulation in single scale is difficult to meet the needs of understanding multi-scale characteristic of hydrological process and link among processes at different scales. As basic unit of terrestrial hydrological cycle, watershed has clear boundary and become the foundation of hydrological process research and water resource management. Nested watershed is the expression of hierarchical structure of terrain and become a good experiment area for study on hydrological process and upscaling. In this paper, catchment hydrological theory, dynamic data driver application system (DDDAS) paradigms, and scale theory are applied to construct a multi-scale distributed hydrological model research framework, and some key techniques of multi-scale surface runoff model was solved to support the research on scale effect of hydrological process and upscaling in nested watershed. The main research result follows below.Based on digital terrain analysis and DEM, a research framework of multi-scale distributed hydrological model is put forward. It can support the research and test for identifying main hydrological process at different scales based on different basic model unit, for hydrological process interaction and nesting at different scales in nested watershed by nesting model output at small scale unit into model input at large scale, for capturing hydrological pattern at catchment scale and assisting decision of water resource management by combining multi-scale monitoring data with hydrological model at the proper scale.Based on research of automation segementation of watershed terrain, a multi-scale geomorphy unit family is formed. A new algorithm of auto-generating DEM from digitalized contour based on mathematical morphology is presented for Geomorphologically sound DEM. By comparison of the Methods for extracting digital channel network from DEM, a set of techniques is applied to discretization the watershed into small geomorphy element at different scales. Based on flow Path from DEM data, the method of automated extraction of shoulder line of valley is presented. All of above techniques is integrated to segment watershed into cell, hillslope, catchment and hierarchical nested watershed.A process system for automation of multi-scale geomorphy parameter is developed. Based onautomation segementation of watershed terrain, the algorithm of geomorphy parameters at different scale is described and their dependency relationships is analysed. Take the terrain data of Caijiachuan nested watershed in west Shanxi as an example, geomorphy parameters at different scales is produced and multi-scale analysis is conducted to discovery the rules of scales’ changes on them.Under the guidance of DDDAS paradigms, the construction techniques of dynamic distributed hydrological model is studied and a distributed surface-runoff simulation system is developed with support for three basic model units. The simulation system gets the model unit parameters from above process system of geomorphy parameter and support coupling of watershed runoff processes and interaction between simulation processes at different scales. The system is designed to be open and flexsible, and provide virtual laboratory for research on hydrological process simulation and upscaling.Application research of surface runoff model in Caijiachuan nested watershed shows that the model developed in this paper can reflect the impact of the rain pattern on watershed hydrograph and route the simulation of small catchment into large catchment. Finally the impact of forest and human activities on hydrological process and nature environment can be evaluated.更多还原