Study on the methods of extracting urban land-use information based on landsat imagery taking - Quanzhou city for example

How to extract exactly urban land-use information is always very important in application of remote sensing. There are various methods of extracting urban land-use information based on Landsat image. The approaches studied were Normalized Difference Built-up Index (NDBI), spectrum threshold extraction, supervised classification by computer and interactive visual interpretation; however, each of them has its own advantages and disadvantages in specific application. The main objective of this paper is to compare the efficiencies and accuracies between the multiple methods, and to analyse their potential to improve the efficiencies and accuracies. For instance, the NDBI method is ameliorated by setting a threshold to improve its accuracy. In this study, we take Quanzhou city as study area, and utilize Landsat ETM+ image acquired in 2000 to extract the urban land-use information using the abovementioned methods respectively. By comparison, the study result reveals that these ameliorated methods can work better than before, and NDBI can extract information easily and quickly, and Spectrum Threshold Extraction can acquire high accuracy at the cost of complexity.