五华县油田镇崩岗侵蚀的时空分布变化与成因分析

发布时间：2018-03-07 15:45

本文选题：崩岗　切入点：时空分布规律　出处：《江西农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：南方红壤区的崩岗侵蚀以广东省地区最为剧烈,而五华县的侵蚀程度又位列该区域首位,是崩岗分布的标志性地区。本文以五华县油田镇作为研究区,收集1978年、1995年的地形图以及2005年崩岗普查资料,采用ArcGIS、RDA分析与人工处理相结合的方法分析崩岗的时空分布规律,并揭示崩岗分布的原因。研究结果如下:(1)1978~2005年时段油田镇崩岗表现为先减少再急剧增加趋势,总体呈现增加的态势,其中个数、面积、体积分别增加了380%、632%、494%,侵蚀模数为30489.4t/(km2?a),相当于每年侵蚀地面22.6 mm,属于剧烈侵蚀范围。从崩岗规模看,崩岗由中、大型崩岗为主向大型崩岗集中的方向发展。(2)崩岗侵蚀的空间分布规律:油田镇崩岗主要集中在西南区域的万华村、洋坑村、下陶村,呈现西南向东北递减的分布特点。崩岗主要出现在海拔高度100~300m,相对高度在0~60 m,坡度在15°~35°的陡坡及急陡坡,坡向为阳坡的丘陵地带,并且存在海拔高度、相对高度、坡度的分布表现为先增多再急剧减少的趋势,阳坡与阴坡崩岗之比约为3:1的特征。(3)崩岗侵蚀随时间变化规律:1978~2005年,从不同年代崩岗整体分布看,其分布特征有小范围的差异,但总体分布情况保持一致;从单项指标变化看,崩岗行政区域分布、高程分布、坡度分布、坡向分布变化结果虽然复杂多样且无明显规律,但不同类型分布的变化基本与该时段的侵蚀现状变化情况一致,均有在前期(1978~1995)变化较平缓,在后期(1995~2005)急剧变化的规律。(4)相对高度对单个崩岗发挥主要的作用,最高海拔、加权坡度等因子对崩岗分布也有重要影响。坡向、最低海拔等其他因子对崩岗的影响较小。(5)坡度、坡向、高程等地貌因素对区域崩岗的分布发挥主要作用,经济、社会因素、植被因素对其表现为辅助作用。
[Abstract]:The collapse erosion in southern red soil region is the most severe in Guangdong Province, and Wuhua County is the first one in this region, which is the landmark area of collapse distribution. This paper takes Yutian Town, Wuhua County, as the research area. The topographic map of 1978 and 1995 and the general survey data of collapsing hill on 2005 were collected. The temporal and spatial distribution of the collapse was analyzed by combining ArcGISRDA analysis with manual processing. The results of the study are as follows: in the period of 1978-#date0#, in Yutian Township, the tendency of collapse was first reduced and then increased sharply, and the number, area and volume of the collapse were increased by 380, 632 and 494, respectively, and the erosion modulus was 30489.4 t / r / km2? A, equivalent to the annual erosion of the ground 22.6 mm, belong to the scope of severe erosion. The spatial distribution of collapse erosion in Yutian Town is mainly concentrated in Wanhua Village, Yangkeng Village and Xiatao Village in southwest China. The slope collapse occurred mainly at the elevation of 100 ~ 300 m, the relative height of 0 ~ 60 m, the gradient of 15 掳~ 35 掳and the steep slope. The slope was a hill with a sunny slope, and there were elevation and relative height. The slope distribution shows the tendency of increasing first and then decreasing sharply. The ratio of sunny slope to shady slope is about 3: 1. The slope erosion changes with time. From 1978 to 2005, the distribution characteristics of slope collapse are different in a small range from the whole distribution of collapse in different years. But the overall distribution remained the same. From the point of view of the single index change, the distribution of administrative area, elevation distribution, slope distribution, slope direction distribution, although the result is complex and diverse and has no obvious rule, However, the variation of distribution of different types is basically consistent with the current situation of erosion in this period, and the change is relatively gentle in the early stage of 1978-1995), and the law of sharp change in the late stage of 1995 / 2005. (4) the relative height plays a major role in the single collapse, the highest elevation. Other factors, such as slope direction, minimum elevation and other factors, have a small influence on the slope, slope direction, elevation and other geomorphological factors, which play a major role in the distribution of regional collapse, economic and social factors. Vegetation factors play an auxiliary role to it.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.2;P931

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