Large Time Series Models in Hydrology: A Study of Water Level Forecasting in Everglades
This paper evaluates the performance of large time series models within the domain of hydrology, specifically focusing on the application to water level forecasting in the Everglades. Recognizing the critical role of accurate water level predictions in regulating floods, droughts, and ecosystem management, the paper investigates the efficacy of twelve task-specific models and five foundation models. These models are examined across multiple forecasting horizons and measuring stations, providing comprehensive insights into their strengths and limitations.
Key Findings
Foundation Models vs. Task-Specific Models
The paper finds that the foundation model Chronos significantly excels in zero-shot inference across various locations and forecasting horizons. Contrarily, other foundation models, including Moirai, Timer, and TimesFM, demonstrate relatively poor performance. This emphasizes the selective success of certain pre-trained models, such as Chronos, which might be attributed to the diverse datasets used during its training, potentially including climate datasets that better correlate with Everglades data.
Model performance inherently varies across measurement stations, with NP205 exhibiting weaker correlations with other stations resulting in higher prediction errors. Chronos maintains superior accuracy across all station types, showcasing its robustness. Most task-specific models such as NBEATS, PatchTST, and RMoK, offer strong performance but require retraining for each specific dataset or experimental condition, highlighting a key limitation in scalability and adaptability compared to foundation models.
Extreme Value Prediction
Sediments of extreme values, both high and low, are particularly challenging to forecast accurately. Chronos again outperforms other models in terms of capturing these extremes, as measured by the Symmetric Extremal Dependence Index (SEDI). The analysis highlights the difficulty all models face in predicting abrupt changes, a common occurrence in hydrological datasets.
Implications for Hydrology and Water Management
This research conveys significant practical and theoretical implications. On the practical aspect, it highlights the potential for scalable deployment of foundation models in real-world water management tasks, such as flood control and ecological conservation efforts. Theoretical implications involve the opportunities for advancing these models further in hydrology, particularly by integrating more contextual hydrological datasets during pre-training.
Speculations for Future Research
The paper suggests that future advances could be made by improving the architectural paradigms utilized by foundation models. This involves not just scaling parameters but also optimizing the depth and complexity of correlation-capturing mechanisms. Moreover, expanding datasets for pre-training across diverse environmental and hydrological conditions could drastically improve generalizability and accuracy in zero-shot settings. Addressing extreme value predictions remains an area ripe for innovation, potentially through hybrid models unifying data-driven approaches with traditional hydrological theory.
Overall, while the task-specific models offer targeted accuracy, foundation models such as Chronos provide promising solutions for broad, adaptive applications within environmental hydrology. Further exploration and refinement in these areas hold the potential for significant advancements in predictive accuracy and operational efficiency.