Cropping intensity mapping in Sentinel-2 and Landsat-8/9 remote sensing data using temporal transfer of a stacked ensemble machine learning model within google earth engine

Abstract

This article aimed to map Cropping Intensity Patterns (CIPs) in the southwest region of Iran using Google Earth Engine and monthly composites of Sentinel-2 and Landsat-8/9 data. To detect CIPs with high inter- and intra-class variability of crops, a heterogeneous Stack ensemble of machine learning model was developed. The model incorporated the Minimum Distance (MD) approach as a meta-classifier, combining multiple base models, including Support Vector Machines (SVM), Random Forest (RF), Classification and Regression Trees (CART), and Gradient Boosted Trees (GBT). In 2021, the Stack model was trained and evaluated using Ground Truth (GT) samples from the same year, achieving an Overall Accuracy (OA) of 94.24%. This performance surpassed the base models by about 4% in OA and was also reflected in the detection accuracies, including User’s Accuracy (UA), Producer’s Accuracy (PA), and F1-score, of the target classes. Subsequently, the trained stack model was temporally transferred to generate CIP maps for other years. The model achieved high OAs of 91.82% and 90.97% based on GT samples from 2020 and 2022, respectively. Finally, the time series of CIP maps (2019-2023) were utilized by the Cellular Automata-Markov model to forecast the map for 2024.