【作者】 李海彬；

【导师】 胡旭跃；

【作者基本信息】 长沙理工大学 ， 水力学及河流动力学， 2008， 硕士

【摘要】 洞庭湖是世界上最为重要的湿地之一,对调节长江流域生态环境具有无可替代的多种功能和作用。随着长江三峡水利枢纽蓄水运行,洞庭湖天然湿地的演变趋势已成为人们关注的焦点问题。本文以1973年～2005年43个时相的卫星遥感数据为基础,利用多时相遥感动态分析方法,分别从三峡运行后三口分流分沙减少、三峡水库调度引起洞庭湖水情变化两个方面出发,分析三峡工程运营后洞庭湖湿地的演变趋势。经分析,下荆江河道裁弯取直工程与三峡蓄水都将造成三口分流分沙减少,因此,本文采用类比的方法,在对1973年、1989年、1996年和2005年洞庭湖枯水季节的卫星图像进行预处理以及监督分类的基础上,首先研究荆江裁弯后洞庭湖天然湿地的演变规律,再进一步探讨三峡水库运行对洞庭湖天然湿地资源的影响。结果表明,三峡工程建成运行,对扩大洞庭湖湖水面积,延长洞庭湖的寿命有着积极的作用。通过对1993年～2006年33个时相的TM/ETM+卫星遥感数据进行湖泊信息提取,结合前人的研究成果,采用最小二乘法,建立了三峡水库增、减下泄流量～洞庭湖面积(容积)增、减数学模型,经分析发现,三峡水库调度引起的洞庭湖面积和容积的变化主要在湖中部平坦地区,以5月份与10月份最为明显。上述研究结果表明,三峡工程对扩大洞庭湖湖面面积、延长洞庭湖寿命有积极的作用,但三峡水库调度将使洞庭湖的洲滩淹没时间发生变化,在一定程度上打破了洞庭湖原有的生态平衡,给洞庭湖湿地生态系统带来一定负面影响。因此,进一步分析三峡工程运行引起的洞庭湖形态变化及由此引发的生态环境变化是一个十分紧迫的课题。更多还原

【Abstract】 The Dongting Lake, which is one of the most important wetland in the world, plays multiple important roles that can’t be displaced in regulating the ecological environment of the Yangtze River. With the running of Three Gorges, it is a focused problem about the evolution trend of Dongting Lake wetland.On the basis of 43 satellite imagines from 1973~2005, the evolution law of Dongting Lake wetland is studied using a dynamic multi temporal remote sensing analysis in this paper from two aspects: 1. the amount of diverted runoff and sediments from Three Outlets will be decreased after the running of Three Gorges; 2. Regime of Dongting Lake will change after the operation of Three Gorges.Firstly, the result, caused by Three Gorges and three river cut off projects in lower Jingjiang stretch in 1967~1972, is quite similar that the amount of diverted runoff and sediments from Three Outlets will be decreased. In this paper by means of processing four phrases remote sensing imagines (1973, 1989, 1996, and 2005) and carrying out supervised classification, the influence of Three Gorges on the Dongting Lake wetland resources is studied on the basis of analyzing the evolution law of Dongting Lake wetland after river cut off projects in lower Jingjiang stretch. The analysis shows that the Dongting Lake wetland has a tendency of regressive succession after the running of Three Gorges.And then, in this paper by means of picking up the lake information from 33 phrases remote sensing imagines from 1993~1996 and combined with the previous achievements, the mathematical relation model between discharge increased in the low-water season (or decreased in the flood season) of the Three Gorges Reservoir and the increased (or decreased) of the area and the volume of Dongting was built. The analysis shows that the lake area (volume) amplitude caused by the operation of Three Gorges mainly occurred in the middle and flat area, and the effect is more obvious in May and October.Based on the results obtained, The Three Gorges will play a positive role in prolonging the life of Dongting Lake, on the other hand, it also will brings some adverse influences on the ecological system of Dongting Lake. It was a practical and immediate topic to make further research on the change of the hydrology and the ecological environment of the Dongting Lake.更多还原