四湖流域水文连通度及其对洪水期水文过程的影响

发布时间：2018-06-03 20:02

本文选题：四湖流域 + 水文连通度　；参考：《华中师范大学》2014年硕士论文

【摘要】：水文连通度对于平原河网水系具有重要作用,良好的水文连通度有利于良好水质的保持、保护湿地生态环境、洪涝灾害的防治、提供稳定的水资源等。反之,不良的水文连通度容易引起一系列生态环境问题,河流连通结构阻断、湖泊湿地萎缩消亡、洪涝干旱灾害频发等。四湖流域地处江汉平原,生态环境问题较多,生态环境问题已经成为制约该地区发展的主要因素。近些年来随着社会经济的发展,四湖流域人类活动对河湖环境演变的影响逐渐加强。人为因素的干扰破坏了水系水体之间连接,四湖地区的水系结构发生改变,水文连通度下降,导致河湖环境演变并产生功能失调。洪水期水文过程受到影响,因河系水网的阻隔,易产生外洪内涝的洪水期水文过程。水旱灾害频在一定程度上恶化了生态环境和流域范围内人类的生存环境。本文利用GIS技术,DEM影像数据与四湖流域近50年的洪水期降水数据得出洪水期水文过程的变化。利用四湖流域1954年和2005年水系结构矢量化地图通过景观生态学的廊道节点方法,对四湖流域水文连通度进行评价。以此来探讨四湖流域水文连通度的变化对洪水期水文过程的影响。本文的主要结论为： (1)从20世纪50年代以来,四湖流域水文连通度呈明显下降趋势。流域总体水文连通度下降。流域三个区域中,上区水文连通度水平保持较好,为优等。中区水文连通度下降最明显,由原来的优等水平,下降为良等水平,下降了一个等级。因中区河湖消失情况严重。下区水文连通度下降也非常明显,由优等水平降为中等水平,下降了两个等级。四湖流域水文连通度下降的最主要的因素是人类活动的影响。 (2)四湖流域受人类活动的干扰水文连通度呈明显下降趋势,这导致四湖流域在洪水期水文过程更加复杂,降雨产生的地表径流是本地区产生外洪内涝情况的主要原因。而随着水文连通度的降低,四湖地区防洪水流压力增大,降雨汇流不能迅速在本区域消化。同时旱灾年份,水资源因河湖水系连通水平低,河湖阻断,江河分离,不能及时合理调配水资源。
[Abstract]:The hydrological connectivity plays an important role in the river network of the plain. Good hydrological connectivity is beneficial to the maintenance of good water quality, the protection of wetland ecological environment, the prevention and control of flood and waterlogging, and the provision of stable water resources. On the other hand, poor hydrological connectivity can easily lead to a series of ecological environmental problems, river connectivity structure blocking, lake wetland atrophy and extinction, frequent flood and drought disasters, and so on. The four lakes basin is located in Jianghan Plain, and there are many ecological environmental problems, which have become the main factors restricting the development of this area. In recent years, with the development of social economy, the influence of human activities on the evolution of river and lake environment in the four lakes basin is gradually strengthened. The disturbance of human factors destroys the connection between the water systems, changes the water system structure in the four lakes, and reduces the hydrological connectivity, which leads to the evolution of the river and lake environment and the maladjustment of its function. The hydrological process during flood period is affected, and the hydrological process of external flood and waterlogging is easy to occur because of the blocking of river network. The frequency of flood and drought disasters has deteriorated the ecological environment and the human survival environment in the river basin to a certain extent. In this paper, the variation of hydrological process during flood period is obtained by using GIS technique and Dem image data and precipitation data of four lakes basin in recent 50 years. The hydrological connectivity of the four lakes watershed was evaluated by using the vectorized map of water system structure in 1954 and 2005 through the corridor node method of landscape ecology. The influence of the change of hydrological connectivity on the hydrological process during flood period is discussed. The main conclusions of this paper are as follows: Since the 1950s, the hydrological connectivity of the four lakes basin has decreased obviously. The total hydrological connectivity of the basin decreased. In the three regions of the basin, the level of hydrological connectivity in the upper region is good and excellent. The hydrological connectivity of the central region decreased most obviously, from the original superior level to the good level, which decreased by one grade. Due to the disappearance of rivers and lakes in Central District, the situation is serious. The decrease of hydrological connectivity in the lower region is also very obvious, from the superior level to the medium level, which is reduced by two grades. The main factor of the decrease of hydrological connectivity in the four lakes basin is the influence of human activities. 2) the hydrological connectivity of the four lakes basin affected by human activities is decreasing obviously, which leads to the more complicated hydrological process in the flood period, and the surface runoff caused by rainfall is the main reason for the external flood and waterlogging in this area. However, with the decrease of hydrological connectivity, the pressure of flood control flow in the four lakes increases, and the rainfall confluence can not be digested rapidly in this region. At the same time, in drought years, water resources cannot be allocated in time due to the low level of river and lake water system connectivity, the blocking of rivers and lakes, and the separation of rivers and rivers.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P333

【引证文献】