A Deep Learning-Based Precipitation Downscaling Models with Terrain-Guided Attention

Expand
  • 1. School of Computer ScienceXian Shiyou UniversityXi'an 710065ShanxiChina
    2. State Key Laboratory of Loess ScienceInstitute of Earth EnvironmentChinese Academy of SciencesXi'an 710061ShanxiChina

Online published: 2026-04-13

Abstract

As a powerful deep-learning downscaling techniqueconvolutional neural networks CNNsare widely utilized to generate high-resolution precipitation data from low-resolution global climate models through data-driven approachesplaying a critical role in assessing the impacts of climate change at both regional and lo‐ cal scales. This study proposes a CNN-based precipitation downscaling modelthe Topography-Guided Attention NetworkTGAN),which downscales coarse-resolutionatmospheric variables to produce high-resolution precipitation fields at 0. 1° . The model adopts a Laplacian pyramid as a progressivemulti-level downscaling frameworkin which the spatial resolution of precipitation fields is incrementally enhanced and precipitation structures are reconstructed through successive stages. In additiona topography-guided attention module is in‐ corporatedwhich leverages an attention mechanism to integrate atmospheric variables with elevation data at cor‐ responding spatial scales. By combining these multi-scale featuresthe module strengthens the network’s capaci‐ ty for feature representation and learningthereby improving the accuracy and reliability of simulated precipita‐ tion. Focusing on the middle reaches of the Yellow RiverTGAN is trained on daily ERA5 atmospheric vari‐ ablesGPM IMERG daily precipitation data from 2001 to 2010together with static elevation dataand validat‐ ed using data from 2011 to 2020. The results indicate thatcompared with a conventional CNN modelTGAN achieves higher accuracy in spatiotemporal precipitation simulations at dailymonthlyand annual scales. At the daily scaleTGAN achieves a lower average root mean square error5. 10 mm/dayand a higher average corre‐ lation coefficient0. 42compared with the conventional CNN model. AdditionallyTGAN more accurately captures extreme precipitation events95th and 99th percentilesand better aligns with GPM IMERG observa‐ tions in probability density distributionparticularly for heavy precipitation range. This study further investigates the impact of different loss functions on the downscaling performance of TGAN. Using the RMSE loss function improves overall predictive accuracy but leads to underestimation of extreme precipitation eventswhereas the Bernoulli-Gamma loss functionalthough slightly less accurate overallmore faithfully reproduces extreme pre‐ cipitation events. Its probability density distributions are highly consistent with both GPM IMERG data and sta‐ tion observationsindicating that the model has an enhanced capability to capture extreme precipitation eventsthereby better reproducing the distribution characteristics of precipitation frequency. Overallby combining the topography-guided attention mechanism with the Bernoulli-Gamma loss functionTGAN demonstrates clear ad‐ vantages in downscaling precipitation over the middle reaches of the Yellow Rivernot only improving overall simulation accuracy but also better representing extreme precipitation eventsproviding a robust and reliable tool for high-resolution precipitation modeling in complex terrain regions.

Cite this article

WANG Cailing, FAN Lei, XIE Xiaoning . A Deep Learning-Based Precipitation Downscaling Models with Terrain-Guided Attention[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00098

Outlines

/