Where are the outcrops? Automatic delineation of bedrock from sediments using Deep-Learning techniques

Abstract

The delineating of bedrock from sediment is one of the most important phases in the fundamental process of regional bedrock identification and mapping, and it is usually manually performed using high-resolution optical remote-sensing images or Light Detection and Ranging (LiDAR) data. This task, although straightforward, is time consuming and requires extensive and specialized labor. We contribute to this line of research by proposing an automated approach that uses cloud computing, deep learning, fully convolutional neural networks, and a U-Net model applied in Google Collaboratory (Colab). Specifically, we tested this method on a site in southwestern Norway using both a set of explanatory variables generated from a 10 m resolution digital elevation model (DEM) and, for comparison, cloud-based Landsat 8 data. Results show an automatic delineation performance measured by an F1 score between 77% and 84% for DEM terrain derivatives against a manually-mapped ground truth. Overall, our automated bedrock identification model reveals very promising results within its constraints.