Time series remote sensing based dynamic monitoring of land use and land cover change

摘要

Land use and land cover (LULC) change monitoring is still an important remote sensing application and research field, for it is closely related to manage natural resources and environmental planning. This study is aimed to find the land use and land cover changes of Zigui County from 2008 to 2014 by using multi-source remotely sensed imagery. Images of three different years (2008, 2011 and 2014) taken from Landsat and other three satellites (GF-1, HJ-1 and SPOT) were used to monitor the land use and land cover changes in this study. Landsat images were used as the main references for analysis while the others were used associative for some enhancement. In order to increase the accuracy of the results, we abandon the single resolution image and use different spatial and spectral resolution images simultaneously in the classification and other processing stage. Three different methods to determine the changes of land use and land cover have been used in this paper: transfer matrix of land use, changes related to the terrain of earth surface and landscape pattern of composition changes. Thematic maps have been prepared showing the land use and land cover classes in individual year as well as the changes during different time interval to identify the spatial changes. Changes related to the terrain have been statistics using classified images and digital elevation model (DEM). Quantitative analysis of each phase of the land use and land cover pattern characteristics using part of the landscape pattern indexes. The result of the study illustrates that: 1) the area of built-up and cultivated have the rapid and continuous growth and the area of vegetation descended. And the new construction land mainly by agricultural land conversion, the forest area reduced mainly converted to the agricultural land; 2) vegetation and agricultural land change mainly concentrated in the 500 meters below, have slight change in in 1000 to 1500 meters and no significant changes in other altitude; 3) From patch density(PD) and other landscape metrics analysis result, built up area is increasing not only in amount but also in number of patches, that is, the new built up areas area being established frequently. And the number of buildup area patches is almost four times increased within 6 years.