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康保县景观格局变化及其生态效应分析
Study on the Landscape Change and Its Ecological Effects in Kangbao
【作者】 郭晓妮;
【导师】 马礼;
【作者基本信息】 首都师范大学 , 自然地理学, 2009, 硕士
【摘要】 景观是人类生活的载体,人类的一切社会活动和经济活动都是在一定的区域景观内进行。人类活动是形成景观,构建自然和人工管理斑块组成镶嵌体的重要动力。人类是景观变化的原始动力,也由此导致了目前的生态危机(Naveh,1995)。对景观格局变化研究,是进行景观生态学评价、景观生态设计管理等的基础,尤其在生态环境脆弱的地区,对于促进该地区的生态环境的改善和可持续发展具有重要理论与现实意义。康保县地处河北省坝上高原,是我国北方农牧交错带中段的典型地区,是生态环境的典型脆弱区。因此,研究其景观格局变化,并探讨变化的驱动力因素以及生态效应,对于改善本区生态环境,充分认识人类活动的利弊,促进坝上地区资源的合理利用,保障生态和粮食安全无疑具有重要意义。本文以康保县1987年、2000年、2005年三期Landsat-TM/ETM遥感影像为基础,从综合自然地理学、景观生态学的角度出发,在遥感(RS)、地理信息系统(GIS)等技术的支持下,结合康保县的区域特征,对康保县景观格局的变化进行分析,并在此基础上定性分析了该地区景观格局变化的驱动力,最后结合气候气象资料、野外实测数据及相关资料对景观格局变化的生态效应进行了分析。结果表明:(1)1987年研究区主要景观类型为耕地、草地、建设用地;2000年研究区主要景观类型为耕地、草地、林地和建设用地;2005年主要景观类型也为耕地、草地、林地和建设用地。通过对这三年的景观类型面积的相互对比可以看出,耕地面积不断减少,林地、草地面积呈大幅度增长,尤其在2000年至2005年这一研究区间内变化比较剧烈,建设用地面积也呈现出增加的趋势,未利用地面积先增加后减少。(2)基于单一土地利用类型动态度模型和综合土地利用动态度模型的分析结果,研究区整体景观变化速度较大。18年间,林地和草地都有了一定幅度的增长,尤其在2000年至2005年,林地的动态度高达38.48%,草地的动态度也达8.47%,建设用地也一定程度的增加,但变化幅度小于林地和草地;耕地不断减少,动态度为--4.69%。(3)通过景观类型转移矩阵分析可知,耕地面积大幅度减少,林地、草地面积大幅度增加,建设用地、未利用地均有一定程度的增加,水域面积持续减少。景观类型转移以耕地——草地,耕地——林地,林地——草地为主,且这些景观类型间的相互转化均是双向的。(4)利用景观格局指数对康保县景观格局变化进行分析,结果显示:1987年至2005年,康保县各景观要素斑块中,耕地、林地、建设用地、未利用地的斑块数量增加,草地、水域的斑块数量有少量的减少;1987年至2000年,耕地、林地、未利用地平均斑块面积向小型化发展,破碎度增加,而草地、建设用地的斑块向大型化发展;2000年至2005年,林地、草地、建设用地、水域的平均斑块面积有所增加,耕地、未利用地的平均斑块面积持续减少。1987年至2005年,各要素斑块的景观形状指数除未利用地外,全部都有了一定程度的降低,这说明斑块形状的复杂程度降低。在景观水平上,康保县景观的斑块数和密度都有所增加,多样性指数(SHDI)、均匀度指数(SHEI)均在增加,优势度(D)在减小,这说明康保县景观各要素的分配正在变得均匀,且景观异质性增加。蔓延度(CONTAG)在减小,平均斑块分维数(FRAC_MN)接近1,这说明康保县人类对景观的干扰程度较大,斑块相似性较强,破碎化程度变高。(5)对于本研究区,景观格局变化的最基本的驱动因素在2000年之前是自然因素和人口因素;到2000年之后,政策因素(退耕还林草政策)便成为康保县景观格局变化的最主要的因素。(6)景观格局的变化也反过来影响着自然环境以及人类的生产活动,本文利用野外实测数据较详细地分析了景观格局的变化(退耕还林草)对研究区域内土壤的影响。结果表明,在一定程度上,发现退耕还林草能够提高土壤养分水平,起到了较好的土壤生态效应,使得土壤质量在不同程度上得以恢复和提高;并且对减缓土壤风蚀起到了积极的作用。另外,景观格局的变化也将在一定程度上影响该地区的小气候和生物种类的变化。
【Abstract】 Landscape is the carrier of human life,All the social activities of human and economic activities are certain to carry out the regional landscape. Human activity is the formation of the landscape, Construction management of natural and artificial patch mosaic composed of an important driving force. Human beings are the primary driving force for landscape change, this also led to the current ecological crisis(Naveh,1995) . Change of landscape pattern is the evaluation of landscape ecology, landscape management, eco-design basis.In particular, a fragile ecological environment in the region, In the region to promote the improvement of ecological environment and sustainable development has an important theoretical and practical significance.Kangbao County is located in Bashang plateau of Hebei Province, is the agro-pastoral transitional zone in northern China the middle of a typical region and typical of the fragile ecological environment in the district. So Study the landscape pattern change, and to explore the factors driving force of change and the ecological effects, for improving the ecological environment in this area, fully understand the pros and cons of human activities, promote the rational use of resources in Bashang region, the protection of ecological and food security is undoubtedly of great significance.This article based on three remote sensing image Landsat-TM/ETM in 1987,2000,2005. From the view of the integrated physical geography, landscape ecology , with the support of remote sensing (RS), geographic information systems (GIS) technology and so on, combined with the regional characteristics of kangbao country, analysised the changes in landscape pattern of kangbao country, qualitative analysised the driving force of change of landscape pattern in the region, finally ,combined with climate weather data, field measured data and relevant information, analysised the ecological effects of Landscape pattern changes. The results showed that:(1)In 1987,Arable land, grassland, land for construction purposes are the main landscape types in this region; In 2000, Arable land, grassland, forest and construction land are the main landscape types in this region; In 2005,the same as 2000.By the contrast of the area of different types of landscape in these three years, we can see: the area of arable land steadily decline, woodland, grassland showed a substantial increase, especially this region has a dramatic change in 2000-2005, construction land area showed an increasing trend, an area of unused land to reduce the increase.(2)Based on the analysis of the single type of land use dynamic degree model and the integrated dynamic model of land use, the region has the larger speed of the overall landscape changes. 18 years,the woodlands and grasslands have a certain growth rate, especially in 2000 to 2005,the dynamic degree of woodland is 38.48%, the dynamic degree of grassland is 8.47%, construction land is also a certain degree of increase, However, changes in less than woodland and grassland, Steady decline in arable land, the dynamic degree is - 4.69%.(3)Through the analysis of the transfer matrix of landscape types,we can see: Substantial reduction in arable land’s area, a significant increase in Woodland and grassland’s area, construction land, unused land has increased to some extent, the waters continued to decrease in size. The main transfer of landscape types are arable land - grassland, arable land - forest, woodland– grassland, and these landscape types are of each other into a two-way.(4)Use the andscape pattern indices to analysis the kangbao country’s changes in landscape pattern, the results show that: 1987—2005, elements of the landscape patch in kangbao country, the number of arable land, forest land, construction land, unused land increase, the number of grassland,water has a small reduction;1987—2000,the average patch area of arable land, woodland, unused land go to the small-scale, increasing fragmentation; the patch of grassland and land for construction go to the big-scale. At the landscape level, the number of patches and density increase;SHDI, SHEI increase, D decrease; It said County Mingkang the distribution of the elements of the landscape is becoming even,and landscape heterogeneity increased.(5)The basic drivers of Landscape pattern changes were Natural factors and demographic factors before 2000;after 2000, Policy factors are the main factors.(6)Changes in landscape pattern in turn affects the production of the natural environment and human activities, In this paper,we use the field measured data to analysis the impact of changes in landscape pattern (returning farmland to forest or grassland) to the soil region, the results show that: To some extent, Returning farmland to forest and grass can improve soil nutrient levels, played a better ecological effect of soil; And to mitigate soil erosion has played a positive role; In addition, Changes in landscape pattern will also affect the region’s climate and the types of living creature.
【Key words】 landscape pattern; driving force; ecological effects; kangbao country;
- 【网络出版投稿人】 首都师范大学 【网络出版年期】2009年 09期
- 【分类号】X171
- 【被引频次】6
- 【下载频次】333