平原圩区的水文特征分析与水量交换计算

发布时间：2018-11-17 16:39

【摘要】：我国的平原河网区存在大量的圩区,圩堤的修筑隔断了自然的水流路径,圩堤内外的水量交换则通过涵、闸、泵站等水工设施人工控制。分布式水文模型是流域水文过程模拟与预测的主要手段之一,而现有的分布式水文模型都缺乏针对圩区的水文模拟模块,使其难以模拟平原圩区复杂、独特的水文过程。因此,在充分探究平原圩区水文特征的基础上提出一种适用于平原圩区的分布式水文建模方法,对于提高分布式水文模型在平原圩区的适用性、改善流域生态环境具有重要的理论和现实意义。本文选择位于太湖流域湖西区的溧阳流域作为研究区,在解析平原圩区空间结构与水文特征的基础上,研究不同类型圩区与圩外河道的水量交换机理,建立了圩区内外水量交换计算模型,并将其作为一个功能模块嵌入到SWAT模型中,建立了具备圩区水文模拟模块的分布式水文模型,通过在研究区的实验表明本文构建的圩区内外水量交换计算模型在平原圩区具有良好的适用性。本文主要研究内容与成果如下： (1)通过野外实地考察,分析了平原圩区的类型、空间结构和水文特性。根据圩区所处的地形特点,将圩区分为半山圩、平坦圩和高差圩三种类型,分析了不同类型圩区的内外水量交换机理,根据圩区灌溉、排涝的调度规则建立了圩区内外水量交换计算模型。 (2)对SWAT模型的结构进行了解析,通过编程以及河道演算过程源码的修改,在SWAT模型中集成了圩区水文过程模拟模块,并实现了相应的参数文件定制。 (3)选取溧阳流域为典型研究区,利用集成了圩区模拟模块的SWAT模型进行实验模拟,结果表明,模型修改后胡家圩桥站模拟结果的相对误差、相关系数和纳什系数从37%、0.52和0.41提高到了24%、0.68和0.67,山前桥站模拟结果的相对误差、相关系数和纳什系数从37%、0.69和0.56提高到了26%、0.82和0.78。改进后的模型基本避免了SWAT模型在平原圩区模拟汛期径流峰值偏高、径流峰值提前、径流高峰后径流回落过快的现象,说明本文建立的圩区内外水量交换计算模型能较好模拟流域内圩区的水文过程,有助于提高平原圩区的水文过程模拟的准确性,为分布式水文模型在平原圩区的应用提供了一种方法。
[Abstract]:There are a large number of polder areas in the plain river network area of our country. The construction of the dike has cut off the natural flow path, and the water exchange inside and outside the dike is controlled manually by hydraulic facilities such as culvert, sluice, pump station and so on. Distributed hydrological model is one of the main methods for hydrological process simulation and prediction of watershed. However, the existing distributed hydrological models lack of hydrological simulation module for polder area, which makes it difficult to simulate the complex and unique hydrological process in plain polder region. Therefore, on the basis of fully exploring the hydrological characteristics of plain polder region, a distributed hydrological modeling method suitable for plain polder region is put forward, which can improve the applicability of distributed hydrological model in plain polder area. It is of great theoretical and practical significance to improve the ecological environment of river basin. In this paper, the Liyang basin, located in the western part of Lake Taihu Basin, is selected as the study area. On the basis of analyzing the spatial structure and hydrological characteristics of the plain polder region, the water exchange mechanism of different types of polder areas and river channels outside the fair is studied. The calculation model of internal and external water exchange in polder region is established, which is embedded into SWAT model as a functional module, and a distributed hydrological model with hydrological simulation module in polder area is established. The experiments in the study area show that the calculation model of internal and external water exchange in the polder region is suitable for the plain polder region. The main contents and achievements of this paper are as follows: (1) the types, spatial structure and hydrological characteristics of plain polder are analyzed by field investigation. According to the topographic characteristics of polder area, the polder area is divided into three types: Banshanwei, Pingxu and Gaodaixu. The internal and external water exchange mechanism of different polder areas is analyzed, and according to the irrigation in polder area, the internal and external water exchange mechanism of polder area is analyzed. The calculation model of internal and external water exchange in polder area is established according to the regulation of drainage. (2) the structure of SWAT model is analyzed. By programming and modifying the source code of river course, the hydrologic process simulation module of polder area is integrated in the SWAT model, and the corresponding parameter file is customized. (3) selecting Liyang watershed as the typical research area, using the SWAT model which integrates the simulation module of polder area to carry on the experiment simulation, the result shows that the relative error, correlation coefficient and Nash coefficient of the simulation results of Hujiawei Bridge Station after the model modification are from 37 to 37. 0.52 and 0.41 increased to 240.68 and 0.67, the relative error, correlation coefficient and Nash coefficient increased from 370.69 and 0.56 to 0.82 and 0.78 respectively. The improved model basically avoids the phenomenon that the peak value of runoff in flood season is on the high side, the peak value of runoff is earlier, and the runoff drop is too fast after the peak of runoff in plain polder area by SWAT model. The results show that the calculation model of water exchange inside and outside the polder area can simulate the hydrological process of the polder area in the basin and improve the accuracy of the hydrological process simulation in the plain polder area. It provides a method for the application of distributed hydrological model in plain polder area.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P333

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