Rapid Adaptation of Earth Observation Foundation Models for Segmentation
Karthick Panner Selvam, Raul Ramos-Pollan, Freddie Kalaitzis
TL;DR
This work tackles the problem of rapidly adapting large Earth Observation transformer models for flood segmentation under limited computational resources. It applies Low-Rank Adaptation (LoRA) to the Clay EO-FM encoder, inserting low-rank updates in attention modules while using a custom decoder, and optimizes a joint BCE-Dice loss to produce precise flood masks from Sentinel-1 SAR data. The findings show that LoRA with a mid-range rank (r=256) yields the best in-distribution performance, outperforming both frozen-encoder baselines and infeasible full fine-tuning, with substantial parameter efficiency. OOD evaluation on the Luxembourg flood event reveals generalization improvements with higher LoRA ranks, though challenges remain in transferring to unseen geographical contexts, underscoring the need for robust, resource-aware deployment in disaster response scenarios.
Abstract
This study investigates the efficacy of Low-Rank Adaptation (LoRA) in fine-tuning Earth Observation (EO) foundation models for flood segmentation. We hypothesize that LoRA, a parameter-efficient technique, can significantly accelerate the adaptation of large-scale EO models to this critical task while maintaining high performance. We apply LoRA to fine-tune a state-of-the-art EO foundation model pre-trained on diverse satellite imagery, using a curated dataset of flood events. Our results demonstrate that LoRA-based fine-tuning (r-256) improves F1 score by 6.66 points and IoU by 0.11 compared to a frozen encoder baseline, while significantly reducing computational costs. Notably, LoRA outperforms full fine-tuning, which proves computationally infeasible on our hardware. We further assess generalization through out-of-distribution (OOD) testing on a geographically distinct flood event. While LoRA configurations show improved OOD performance over the baseline. This work contributes to research on efficient adaptation of foundation models for specialized EO tasks, with implications for rapid response systems in disaster management. Our findings demonstrate LoRA's potential for enabling faster deployment of accurate flood segmentation models in resource-constrained, time-critical scenarios.
