基于移动窗口法的岷江干旱河谷景观格局梯度分析

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于移动窗口法的岷江干旱河谷景观格局梯度分析 DOI: 10.5846/stxb201310312639 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目资助（31000222，31170664） Gradient analysis of dry valley of Minjiang River landscape pattern, based on moving window method Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以岷江干旱河谷为研究区，基于GIS技术和移动窗口法对其景观格局梯度变化进行分析，以期为区域的景观格局优化和管理提供支持。根据研究区的形状特征，分别沿干流和支流设置4条样带；选取景观水平下的景观指数，利用FRAGSTATS3.3软件分别采取标准法和移动窗口法获得不同尺度下的景观指数值；综合利用景观指数粒度效应分析、区域面积信息守恒评价方法和景观指数幅度效应评价曲线确定研究区景观格局梯度分析移动窗口尺寸，并计算了此窗口尺度下4条样带上的景观指数，得到沿样带方向的景观梯度格局。结果表明：岷江干旱河谷的景观基质是灌木林地，面积占73.82%。有林地和草地的景观异质性低，居民地和耕地斑块破碎化程度较大。确定了50m的栅格大小，250m的移动窗口尺寸为研究区景观格局梯度分析的窗口尺度；4条样带上各景观指数均随景观类型变化出现不同幅度的上下波动特征，梯度特征明显。处于景观类型过渡地带的区域，景观多样性和异质性增加，破碎化程度高；干旱河谷景观格局梯度变化主要受地形、水热因子，以及堤坝建设和土地开发利用影响。研究作为一种有益的尝试，更精细地分析了研究区的景观格局，能够为河谷地区景观格局量化分析提供参考，但也存在一定不足，需要在今后工作中继续深入研究。 Abstract:Great attentions have been paid on landscape changes in recent years. As a basis of further researches on landscape functions and dynamics, contributes to analyzing spatial distribution characteristics of landscape components, landscape pattern analysis became an important topic of landscape ecology. In landscape pattern analysis, landscape metrics has been used as a common tool to exhibit the spatial distribution of landscape. During the past two decades, many processes have been used to analyze changes of landscape and the relationships with human influences and environmental factors. As a hotspot of quantitative methods of landscape analysis, gradient analysis, which is conducive to revealing the evolutionary laws of spatial landscape patterns has became a significant means in landscape ecology. However, the appropriate spatial scale is the key point to calculate the landscape metrics, and scale issues represent one of the foremost frontiers of landscape ecology. It is well known that the observed landscape pattern and its relationship with (landscape) process depend upon the scale. Great developments have been made on researches on pixel and spatial extent of landscape pattern evolution quantitatively and qualitatively. Little on the accuracy of the landscape analysis is related to both pixel and extent effect since there is the lackage of systematic study on the selection of optimization scale in landscape gradient pattern analysis. In this study, taking the dry valley of Minjiang River as study area and using ARCGIS9.3, ENVI4.8 and FRAGSTATS3.3, based on the image data of Land Resources Satellite ETM+ (2011), we aim to analyze the variation of landscape index with grain size. To obtain gradient patterns of the landscapes, 4 transects have been set up along both mainstream and tributaries of Minjiang River. A series of metrics at the landscape level (NP, PD, LPI, DIVISION, SHDI, and SHEI) were chosen and calculated using standard and moving window approach with different spatial scale, respectively. Then, an optimization-scale selection method, which integrates: the grain effect analysis of landscape index, the data loss assessment and the landscape index range effect curve analysis, was developed to obtain accuracy and efficient scale. By analyzing the grain inflexions of the landscape index comprehensively, we found that 30-90m and 110-160m were the appropriate grain ranges. Data loss assessment showed that 50m was the appropriate grain extent. In addition, based on moving window analysis, landscape index range effect curve analysis suggested that 250m was the most appropriate spatial extent for landscape pattern analysis. At the landscape level, 6 metrics were calculated by Moving window method: shrub land, accounting for 73.82% of the total landscape, was the matrix in dry valley of Minjiang River in the year 2011; the forestland and grassland's landscape heterogeneity decreased and relatively high the fragmentation degree of construct and farmland; water area has no obvious change; landscape metrics in the four transects present different amplitude and evident gradient diversity as landscape type change, the index change is larger in transition zone as compared to the single region; landscape pattern develops in the direction of heterogeneity, diversification and homogenization; and topography, precipitation, temperature and human activities were the factors for the gradient changes of landscape. As a kind of beneficial attempt, this study more finely analyzed the landscape pattern in the study area. The result of landscape pattern gradient analysis provided a novel way for discerning the landscape pattern change in the mountainous areas. 参考文献 相似文献 引证文献