昆明市土地利用变化的强度分析与稳定性研究

在遥感、地理信息系统和统计定量分析结合的基础上,引进土地利用变化强度分析理论方法。作为一种解释性的数学框架,通过不同时间间隔的土地利用转移矩阵计算了每个时间间隔和每种地类的变化面积和变化强度。强度分析自上而下分为3个层次：间隔层次、地类层次和转变层次,将观察变化强度与平均变化强度比较,揭示不同层次的变化特征,并依次用快速的与缓慢的、活跃的与平稳的、来源与转变三对术语来描述。本文以昆明市的土地利用变化为例,深入阐述了不同层次的面积变化和强度变化,并对不同层次的稳定性进行了深入分析。结果表明：在间隔层次,2000年后昆明市的土地利用变化强度逐渐加大;在地类层次,建设用地的变化强度是最活跃的,林地的变化强度是最平稳的;在转变层次,增加的建设用地主要来源于耕地,减少的林地主要转变为草地。强度分析在土地利用变化过程分析中具有系统性的优势,对深入挖掘土地利用变化信息、理解土地利用变化过程具有重要作用。

Intensity analysis and stationarity of land use change in Kunming City

Intensity analysis is a popular method as a top-down hierarchical accounting framework to analyze land use maps by considering cross-tabulation matrices and calculating change area and intensity of each land use category in every time interval with the use of remote sensing, geographic information system, and statistical methods. It was applied to analyze land use changes at three levels: temporal (time interval), categorical (land use types), and direction of conversion. At each level, we compared the observed change intensity to a uniform change intensity in order to reveal the characteristics of change. At the temporal level, we identify in which time intervals changes were relatively fast in terms of overall annual change. At the categorical level, we identify which categories were stable as opposed to active relative to the size of the categories. At the direction of conversion level, when a given category gains or loses, we can identify intensive targeting or avoidance of the other categories. In this article, we took land use change in Kunming City as an example to explore area and intensity changes at different levels and analyze stationarity. The results show that temporally land use intensity in Kunming City has gradually increased since 2000 (in the last time interval). With regard to land use categories, built-up areas’ change intensity was most active, while the change intensity of forests was most stable. With regard to the direction of conversion, the increased built-up areas were mainly from previous cropland, while the reduced forest areas were mainly changed into grassland. Intensity analysis theory has great advantages in analyzing land use change processes, which facilitates the mining of change information and understanding of land use change processes and is very useful for scientists.