Performance of different machine learning algorithms on satellite image classification in rural and urban setup

Abstract

In many countries, the increasing population drives the spatiotemporal land use and land cover change (LULCC) at a higher rate, causing heterogeneous landscape. Hence, the LULCC is a dynamic and frequent process causing fragmented land cover, and therefore, extensive research on LULCC pattern is necessary at different spatial and temporal scales. Moreover, it is essential to identify appropriate algorithms to detect LULCC in such fragmented areas. Furthermore, the rate of change is different in rural and urban areas. Hence, the main goal of the study was to describe the performance of different machine learning algorithms on three different spatial and multispectral satellite image classification in rural and urban extents. We carried out atmospheric and geometric correction. To achieve this, we acquired and processed a set of moderate and finer resolution images (Landsat-8, Sentinel-2, and Planet images) having similar phenological stages to finding out the suitable algorithms that provide better performance in LULC classification. Random forest, Support Vector Machine (SVM), and their combined strength (stacked algorithms) were applied on Landsat-8, Sentinel-2, and Planet images separately to assess individual and overall class accuracy of the images. Two unique sets of training data were generated to classify the 6 (3 sensors x 2 locations) imagery. We find that the Sentinel-2 image performs best among the three images. Among the three different algorithms, SVM showed comparatively better results. In both Bhola and Dhaka, the SVM on Sentinel image performed best with an overall accuracy of 0.969, 0.983, and overall kappa of 0.948, and 0.968, respectively. This study illustrates the role of algorithms on LULCC studies for a better understanding of the changes that occurred in the rural and urban areas. These findings assist planners, remote sensing scientists and decision-makers to choose a suitable image classification algorithm in monitoring rapidly changing, fragmented, and diverse landscape in Bangladesh and elsewhere in the world.