【作者】 王鹏；

【导师】 姚琪；

【作者基本信息】 河海大学 ， 环境工程， 2006， 博士

【摘要】 本文在环太湖丘陵地区选择典型小流域以及径流小区开展野外原位试验，通过野外观测和室内分析相结合的方法，研究小流域及不同土地利用下各形态营养盐在自然降雨-径流驱动下的迁移特征，建立了稻季和非稻季营养盐的迁移通量与径流通量的回归方程，揭示了营养盐在暴雨条件下随径流的流失过程，重点分析了不同土地利用下营养盐迁移的频率分布特征和时空分布特征，以及导致营养盐迁移时空分布存在显著差异的主要原因，对比了不同土地利用下各形态营养盐的迁移通量。 针对平原河网区稻田面积所占比例较高的特点，从稻田水分和营养盐运移转化规律出发，结合土壤胶体对营养盐的吸附—解吸速率公式，动态模拟稻田土壤养分的运移和转化，建立水—土耦合稻田营养盐流失模型，并采用田间实测数据对模型参数进行率定和验证，并对模型关键参数进行灵敏性分析。 在荷兰Delft水力学研究所开发的污染负荷模型（Waste Load Model，WLM）的基础上，将环太湖丘陵小流域的研究成果以及稻田营养盐流失模型引入WLM，通过借鉴非点源污染模型的发展方向和特点，提出适合平原河网区非点源污染物迁移特征的时空分配方法，建立了分布式污染负荷模型（Distributed Waste Load Model，DWLM）。模型将污染源分为工业、大城市居民、城镇居民、农村居民、城市和城镇降雨径流、旱地降雨径流、稻田降雨径流、畜禽养殖和渔业养殖等9种类型，采用四种模式计算各种污染源的负荷量，并根据污染源的迁移特征分别计算其入河过程。 针对平原河网区河道纵横交错、湖泊星罗棋布的特点，分别采用零维、一维和准三维水质模型模拟平原河网区的中小型湖泊、河道以及大型浅水湖泊等水体中污染物的运移转化规律。结合污染物在不同水体中的转化特征，分别建立各种水质指标的动力反应项，对三种水质模型的基本方程组进行耦合联解，并与水量模型实现步长级耦合，建立了平原河网区多维数水质模型。水质模型包含C、N、P三种物质的循环，模拟COD、BOD₅、TN、TP、NH₃-N和DO等六种水质指标。 在3S技术的支撑下，将DWLM模型与降雨径流模型和水质数学模型相耦合，建立了基于数字流域系统的平原河网区非点源污染模型。并将其成功应用于太湖流域平原地区，取得了满意的效果。更多还原

【Abstract】 A typical agricultural watershed and runoff plots in hilly area around Taihu Lake was selected and experiment in situ was conducted. The transporation characteristics of various forms nutrients drived by natural rainfall-runoff were studied by field observations and laboratory testings. Regression relationships between transporation fluxes and runoff fluxes were set up. Temporal variation of agricultural nutrients concentration under storm rainfall condition was analyzed also. Furthermore, different land uses in the watershed were investigated on frequency, temporal and spatial distribution characteristics of nutrients losses in surface runoff. The main reasons about significant difference of temporal and spatial distribution were analyzed and transportation fluxes of nutrients were compared between different land uses.The water-soil coupled nutrient loss model of paddy field had been developed based on the characteristic that paddy field area in plain river network had a large proportion. It can simulate the nutrient transporation and transformation dynamically and adsorption-desorption rate formula of soil colloid was adopted. The parameters of the model were calibrated and verified with field datas, and sensitivity analyses were carried out on critical parameters.Distributed waste load model （DWLM） was derived from waste load model （WLM） developed by Delft Hydraulics Institute, and draw lessons from non-point source pollution model and distributed hydrological model. Research findings of the watershed around Taihu Lake and nutrient loss model of paddy field were introduced into the DWLM. In addition, temporal and spatial distribution method for non-point source pollution of river networks was promoted. The pollution source of DWLM had nine types, such as industries, municipal citizens, town citizens, rural citizens, municipal and town runoff, dryland runoff, paddy field runoff, fish breeding and poultry raising. The waste loads from different pollution source were calculated by using corresponding methods.As channels in river networks area were crisscross and lakes were densely, 0d, 1d and 2d water quality models that had different kinetic reaction items were applied to modeling transportation and transformation of pollutants in medium and small sized lakes, channels and large lake respectively. The basic equations of the different dimensional water quality models were coupled with each other to solving as well as hydrodynamic model. The water quality models were comprised of C, N and P cycling and can simulate 6 water-quality indexes, including COD, BOD₅, TN, TP, NH₃-N and DO.更多还原