天水市土地利用格局变化分析及生态安全评价

发布时间：2018-04-19 22:00

本文选题：土地利用格局 + 景观格局　；参考：《西安科技大学》2017年硕士论文

【摘要】：近年来,随着社会经济发展水平的提高,土地利用格局发生了明显变化,自2009年天水市划入关中-天水经济区后,经济发展致使大量耕地被占用,土地利用结构合理性降低,因此,天水市土地生态安全存在一定风险,科学判断与预测土地生态安全程度具有一定的应用价值。本文利用2005、2010和2015年天水市土地利用数据,借助ArcGIS软件进行土地利用类型面积统计和分析。在此基础上,构建CA-Markov模型预测了 2020年土地利用格局。运用景观生态学,计算并分析了天水市在研究期间的景观格局指数及生态服务价值总量。构建研究区PSR模型,结合研究区实际情况及各景观指数建立指标体系进行2005-2020年土地生态安全评价,得到以下结论:(1)2005、2010和2015年天水市优势土地利用类型为耕地、林地、草地及建设用地。草地和建设用地变化较为活跃,变化幅度最大时分别达到1.3%和4.8%。耕地、林地变化较为平稳,变化幅度基本在0.5%左右。变化趋势不明显的土地利用类型为未利用地和水域。耕地减少部分主要转移到林地、草地和建设用地;林地主要转移到了草地;草地和未利用地的一部分主要转移到耕地、林地和建设用地;建设用地和水域转出较少。(2)利用CA-Markov模型模拟2020年天水市土地利用格局,以此分析未来5年土地利用格局变化趋势以及2005-2020年景观格局变化与生态价值总量,得出2015-2020年天水市土地利用变化趋势稳定,耕地和未利用地面积不断减少,林地、草地和建设用地面积持续增加。景观碎度高,各景观要素之间趋向团聚化。林地与草地面积增加使生态环境价值总量呈上升趋势,但人均生态环境价值减少,其主要原因是人口数量增长。(3)借助PSR模型进行2005-2020年天水市土地生态安全评价,结果显示,土地生态环境压力指标数值2005-2015年增加,而2015-2020年有所下降;土地生态环境状态指标数值处于增加趋势;土地生态环境响应指标数值先下降后上升。总体土地生态安全等级:2005、2010年为风险级,2015年为敏感级,2020年达到良好级。
[Abstract]:In recent years, with the improvement of the level of social and economic development, the pattern of land use has changed obviously. Since Tianshui City was classified into Guanzhong Tianshui Economic Zone in 2009, the economic development has resulted in a large amount of cultivated land being occupied, and the rationality of land use structure has been reduced. Therefore, there are certain risks in land ecological security in Tianshui City, and scientific judgment and prediction of land ecological security degree have certain application value. In this paper, the land use data of Tianshui City in 2005 and 2015 are used to analyze the land use type area with the help of ArcGIS software. On this basis, CA-Markov model was constructed to predict the land use pattern in 2020. Based on landscape ecology, the index of landscape pattern and the total value of ecological service in Tianshui city were calculated and analyzed. The PSR model of the research area was constructed, and the index system was established to evaluate the land ecological security from 2005 to 2020 in combination with the actual situation of the study area and the landscape index. The following conclusions were obtained: the dominant land use types of Tianshui city in 2010 and 2015 were cultivated land and forest land. Grassland and construction land. The change of grassland and construction land was active, and the range of change was 1.3% and 4.8% respectively. The change of cultivated land and woodland is steady, the range of change is about 0.5%. The types of land use which have no obvious change trend are unused land and water area. The decrease of cultivated land is mainly transferred to woodland, grassland and construction land, woodland to grassland, part of grassland and unused land to cultivated land, woodland and construction land; CA-Markov model was used to simulate the land use pattern in Tianshui City in 2020, so as to analyze the change trend of land use pattern in the next five years and the change of landscape pattern and the total ecological value in 2005-2020. It is concluded that the trend of land use change in Tianshui City from 2015 to 2020 is stable, the area of cultivated land and unused land is decreasing, and the area of woodland, grassland and construction land continues to increase. The landscape fragmentation is high and the landscape elements tend to agglomerate. The increase of forestland and grassland area makes the total value of ecological environment increase, but the value of ecological environment per capita decreases. The main reason is that the population increase. The main reason is that the PSR model is used to evaluate the ecological security of land in Tianshui City from 2005 to 2020. The results show that: 1. The value of land eco-environmental pressure index increased from 2005 to 2015, but decreased in 2015-2020; the index value of land ecological environment state increased; the value of land ecological environment response index decreased first and then increased. The overall land ecological security level is 1: 2005, 2010 is the risk level, 2015 is the sensitive level, and 2020 is good.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：F301.2;X826

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