Landslides, as a common geological disaster, are characterized by the rapid movement of large amounts of rock, debris, or soil down a slope, with high frequency and speed1,2. In recent years, with global climate change and increased human activity, landslide disasters have become more frequent, posing a serious threat to human life and property3,4. According to statistics from the World Health Organization (WHO), between 1998 and 2017, 4.8 million people were affected by landslides, and more than 18,000 people lost their lives as a result5. Landslides not only pose direct harm to residents in mountainous and hilly areas but also damage transportation infrastructure, block rivers, and trigger secondary disasters. To effectively mitigate the losses caused by landslides, large-scale landslide detection and monitoring have become increasingly important6,7.
Landslides typically occur in steep mountainous areas, and the factors that trigger landslides usually include excessive rainfall, earthquakes, volcanic eruptions, and snowmelt. The core of landslide identification and detection is determining the location and boundaries of landslides based on various features, including morphological characteristics (such as texture and shape), structural characteristics (such as faults, cracks, and steep slopes), and kinematic characteristics (such as surface movement), to enable large-scale landslide detection3,8–10.
Early landslide identification methods primarily relied on field surveys, which provided detailed data on landslide extent, shape, and structural characteristics11,12. However, field surveys are costly and inefficient, making it difficult to quickly detect and identify large-scale landslide disasters3. In contrast, remote sensing technology, due to its wide spatial coverage and high efficiency, can obtain surface information over large scales and long time sequences, thus demonstrating tremendous potential in landslide detection13. Traditional landslide monitoring methods, such as ground observation and geological surveys, are often limited by complex terrain and harsh environmental conditions, making large-area rapid monitoring challenging. In contrast, remote sensing technology overcomes these limitations, providing multi-source and multi-temporal data to offer rich informational support for landslide detection. Optical remote sensing images can identify characteristics such as the shape, size, spectrum, texture, and patterns of landslides9,14. Therefore, optical remote sensing images and their derived products (such as digital elevation models, slope, surface roughness, etc.) have become the primary data sources for landslide detection15,16.
Deep learning, as a branch of artificial intelligence, provides new ideas for the precise identification of disasters. The landslide disaster feature extraction process based on deep learning requires little to no human intervention to extract the essential and abstract features of the target, offering advantages such as computational capabilities tailored for big data processing. Convolutional Neural Networks (CNNs) are widely used deep learning network models in the field of computer vision, demonstrating excellent performance in image classification, object detection, and semantic segmentation tasks17. In addition, CNNs also show significant advantages in processing remote sensing image data. Many studies have combined CNNs with optical remote sensing images for landslide detection, achieving promising results18–21. The advantage of deep learning over traditional algorithms lies in the ability of multi-layer neural networks to automatically extract useful features. In particular, CNN models extract high-level semantic information from images in addition to local detail features22. CNN consists of multiple nonlinear mapping layers, enhancing the accuracy of landslide disaster recognition by exploring the spatial correlations between target pixels and performing combinatorial analysis to obtain high-dimensional features of the target. These methods can be divided into object detection-based methods and semantic segmentation-based methods. Object detection-based methods use bounding boxes to locate landslides. For example, by combining the YOLO V4 model with attention mechanisms, researchers have utilized optical remote sensing images from Google Earth™ to detect landslides23. Tanatipuknon et al. found that combining two Faster R-CNN models with a simple decision tree can achieve better landslide detection performance24. Semantic segmentation-based methods, such as UNet and FCN networks, can classify landslide and non-landslide pixels to delineate their boundaries. For example, Ghorbanzadeh et al. proposed a new strategy that combines rule-based object-based image analysis (OBIA) with FCN for detecting landslides from multi-temporal Sentinel-2 images25. Lu et al. proposed a dual-encoder UNet landslide detection method based on Sentinel-2 and DEM data for landslide detection26. These studies, on the one hand, demonstrate the potential of the UNet model in landslide detection tasks, while on the other hand, they reveal certain limitations of the UNet model itself, such as the semantic gap between the encoder and decoder and the loss of spatial information during the upsampling process.
The DeepLabv3+ semantic segmentation model is a typical and high-precision network in the field of semantic segmentation, showing excellent performance in remote sensing image processing. However, the DeepLabv3+ model also has some drawbacks. First, its feature extraction network, Xception, has many layers and parameters, resulting in high computational cost and resource consumption, making it difficult for the model to meet the demands of large-scale real-time detection27. Secondly, as the encoder extracts features, the spatial dimensions of the input data gradually decrease, leading to the loss of valuable information. Additionally, the decoder cannot fully recover the details during decoding, ultimately resulting in lower accuracy in identifying the edges of the target27.
In summary, this study aims to address the issues of inaccurate landslide edge extraction in high-resolution images and the large number of parameters and long training times in existing classical semantic segmentation models. To this end, this paper proposes a lightweight landslide disaster detection model, LDNet, based on DeepLabv3+ and attention mechanisms. The main contributions are as follows:
(1) The lightweight network MobileNetv2 is used to replace the Xception backbone of DeepLabv3+, effectively reducing the number of parameters and speeding up the training process.
(2) A lightweight Convolutional Block Attention Module (CBAM) is introduced to filter out background information, allowing the model to focus more on key feature information, thereby improving landslide detection accuracy in complex terrain.
(3) Landslide dataset construction: utilizing multi-source remote sensing data to build a training and testing dataset that covers various types of landslides and different geographical environments, providing strong support for model training and evaluation.
(4) The improved model can quickly and accurately extract landslide locations from high-resolution remote sensing images, providing effective technical support for landslide disaster monitoring.