宁乡县土地利用结构变化及其对水土流失的影响研究

发布时间：2018-01-31 04:53

本文关键词： 土地利用结构水土流失影响宁乡县　出处：《中南林业科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：水土流失是一个全球性的问题。我国是世界上水土流失最为严重的国家之一,随着城市化进程的加快使得我国城市水土流失现象日益严重。水土资源是一个城市发展的根本,是城市得以发展的最基本的物质基础,本文选取宁乡县为研究对象,通过对研究区域内的土地利用结构变化和水土流失强度的分析,并找出它们之间的联系,为我国经济发达城镇地区的土地合理化利用和水土流失防治提供理论依据。主要研究结果如下：(1)研究区域内林地(有林地和灌木林地、常绿针叶林和常绿阔叶林)面积比重较大,呈现片状分布；水田面积次之,水田沿着林地边缘呈线状分布；其他地类面积比例不高,其余地类基本呈现点状分布。(2)研究区域内的水田和旱地面积变化率不高；林地(有林地和灌木林地)面积变化也不大；但是草地和水域面积减少率较大,1986-2005年间草地的减少了4.842km2和10.282km2,面积减少率分别为48.98%和29.09%。(3)研究区域从1986-1995年这9年间无流失面积没有变化,轻度流失面积减少了295.424km2,中度流失、强度流失、极强度流失和剧烈流失面积分布增加5.52%、3.78%、0.84%和0.02%；1995-2002年这7年间无流失面积减少了16.21%,这些基本上全部转化为轻度流失,中度和强度流失面积变化不大,极强度和剧烈流失面积变化率变化较大；2002-005年这3年间流失面积变化,与1986-1995年的变化趋势基本相同,无流失面积基本无变化,轻度流失面积减少,其余流失面积增加,中度流失和极强度流失面积增加率最高,分别达到了112.44%和60.29%。(4)在1986-1995-2002-2005年间,微度流失的斑块数(NP)在逐渐增加,表明微度流失的破碎度在逐渐增加,轻度流失的斑块数在逐渐减少,中度流失、强度流失、极强度流失和剧烈流失斑块数的变化规律不明显；最大斑块数(LPI)在1986-2005年间都是微度流失最大,在1986年时为最大值80.11146,2002年最小为63.3997；1986-2005年间,斑块形状指数都是微度流失轻度流失中度流失强度流失极强度流失剧烈流失；它的变化规律与斑块形状指数的变化趋势一致。(5)从景观角度来看,水土流失斑块数从1986年的1002个增加到了2005年的3211个；斑块密度从1986年的0.3525增加到了1.4763；最大斑块指数和蔓延度指数成减小趋势,而散布与并列指数、多样性指数和均匀度指数增加趋势。
[Abstract]:Soil erosion is a global problem. China is the world's one of the most serious soil erosion in the country, with the city to accelerate the process of making our city soil erosion phenomenon has become increasingly serious. Water resources are fundamental to the development of a city, is the city to the development of the most basic material foundation, this paper selects Ningxiang County as the research object, through the analysis of land use structure change and soil erosion intensity in the study area, and find out the relationship between them, to provide a theoretical basis for economic development in China's urban areas reasonable land utilization and soil erosion prevention. The main results are as follows: (1) in the study area of forest (Woodland and the shrub, evergreen coniferous forest and evergreen broad-leaved forest) area of a larger proportion, showing patchy distribution; paddy field area of paddy field along the forest edge linear distribution area; other than class The rest of the class were not high, showed a punctate distribution. (2) in the study area of paddy field and dry land area change rate is not high; forest (Woodland and shrub land area) has little change; but the grassland and water area reduction rate is larger, 1986-2005 years of grassland decreased by 4.842km2 and 10.282km2, reduced the area respectively. 48.98% and 29.09%. (3) the study area from the 9 years 1986-1995 years without erosion area did not change, mild erosion area decreased by 295.424km2, moderate erosion intensity, erosion, extreme intensity erosion and severe loss distribution area increased by 5.52%, 3.78%, 0.84% and 0.02%; the 7 years 1995-2002 years without the loss of these area decreased by 16.21%. Basically all into mild erosion, moderate erosion area and little change in strength, strength and extremely severe loss area change rate changes; 2002-005 years in the 3 years the loss of area change, and 1986-199 The change trend of 5 years is basically the same, no change of erosion area, mild erosion area decreased, the erosion area increased, moderate erosion and extremely intensity erosion area increase rate is highest, respectively 112.44% and 60.29%. (4) during 1986-1995-2002-2005, micro flow loss of the number of patches (NP) showed a gradual increase in the micro erosion fragmentation of a gradual increase in the number of patches of light erosion is declining in moderate erosion, strength loss, strength loss and variation of extremely severe loss of the number of patches is not obvious; the maximum number of patches (LPI) in 1986-2005 years are slight loss, to the maximum value of the minimum of 63.3997 in 80.111462002 years in 1986; 1986-2005, patch shape index is slight loss of light erosion moderate erosion intensity loss severe severe loss; trend and shape index of it . (5) from the perspective of the landscape, soil and water loss in the number of patches increased from 1002 in 1986 to 3211 in 2005; the patch density increased from 0.3525 in 1986 to 1.4763; the largest patch index and contagion index decreasing trend, and interspersion and juxtaposition index, diversity index and evenness increased the number of index.

【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S157.1;F301.24

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