摘要
基于GIS技术,以塔里木河干流为研究对象,通过缓冲区取样分析了流域整体景观格局及其空间分异特征;针对流域本身自然地理梯度特点,分别在流域5个河段沿横向梯度设置了35个缓冲带,并利用Fragstas软件分别在景观水平和类型水平上选取景观指数,进行景观格局梯度分析与比较。结果表明：①研究区其他类型土地利用占总面积的54.88%,为整个流域景观的背景,植被占35.1%。低覆盖草地占植被面积最大、空间上呈连片的趋势,高覆盖草地空间分布较集中,林地斑块较小,被其他景观分离,空间结构破碎化较严重,耕地斑块数目最多,从上游至下游景观多样性降低,景观异质性减小。②土地利用空间格局异质性特征比较明显,呈现出＂上游—中游—下游＂地域梯度和河道两侧缓冲带梯度格局,河流对景观格局的空间分布有明显影响,由不同宽度缓冲带的景观格局指数分析,塔里木河的宽度效应在河段1、2、3、4分别为8.6~10 km、6.6~8.1 km、4.8~4.9 km、1.4~5 km,各指数随缓冲带宽度的变化趋势反映出河流效应的强弱。③在类型水平上各景观指数反映不同景观类型对河流效应的敏感程度,有林地主要分布在1~5 km,疏林地为1~10 km,高覆盖草地为1~9 km,低覆盖草地为1~12km。以河道为中心建立的辐射缓冲带的景观格局分析方法,很好地揭示了河流廊道—绿洲—荒漠过渡地区景观梯度动态和生态效应幅度,有利于制定更有效的发展政策,为受损生态系统的生态修复提供了有力依据。
In this paper,the holistic landscape pattern and its spatial difference in the mainstream area of the Tarim River in Xinjiang were analyzed based on GIS and quantitative analysis. According to the physical geographical features in the drainage basin,35 buffer zones were delimited along the transversal gradient of 5 river sections,Fragstats was used to select the landscape indexes at both landscape level and landscape type level,and the landscape pattern gradients were analyzed and compared. The results were as follows：（ 1） The area of natural vegetation occupied 35. 1% of the total landscape area,and that of other land use types occupied 54. 88%,so the latter was the background of landscapes in the drainage basin. The area of low-coverage grassland in a continuous distribution trend was the largest,that of high-coverage grassland was spatially distributed in an aggregated way,the patches of forestland were small and were separated by other landscapes,the patch number of farmland was the most,and the landscape diversity and landscape heterogeneity were decreased from the upper reaches to the lower reaches of the Tarim River;（ 2） Heterogeneity of the spatial pattern of land use was significantly high,showing a gradient pattern with geographical gradient and buffer zone,the river corridor change was the driving power resulting in the variation of landscape patterns,the corridor widths of the Tarim River was 8. 6- 10 km,6. 6- 8. 1 km,4. 8- 4. 9km and 1. 4- 5 km along the river section 1,2,3 and 4 respectively. The change trend of the indexes with the change of buffer zone width could be used to reflect the intensity of potamic effect;（ 3） At the landscape type level,the landscape indices reflected the sensitivity degree of different landscape types to the potamic effect,the forestland was mainly distributed in a corridor width of 1- 5 km,the sparse forestland in 1- 10 km,the high-coverage grassland in 1- 9 km,and the low-coverage grassland in 1- 12 km. An analysis method of landscape pattern in buffer z
出处
《干旱区研究》
CSCD
北大核心
2013年第6期1064-1072,共9页
Arid Zone Research
基金
国家自然科学基金(41001066
41171427
41101534)
国家重点基础研究发展计划(2009CB421308)
水利部公益性行业科研专项(201101049)
关键词
景观格局
缓冲区
梯度变化
景观指数
塔里木河干流
landscape pattern
buffer zone
gradient variation
landscape index
mainstream of the Tarim River
