Abstract:

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.

Key words: intensity analysis, cross-tabulation, land use change, stationarity, Kunming City