基于深度学习的黄河上游卫星降水分辨率提升方法

Spatial downscaling of satellite precipitation in the Upper Yellow River Basin using deep learning

  • 摘要: 为提升黄河上游地区卫星降水空间分辨率,利用卷积神经网络(CNN)提取环境因子的空间特征,结合长短期记忆网络(LSTM)捕捉降水时序依赖关系,构建了CNN-LSTM基础模型,并引入迁移学习(TL)策略,建立了CNN-LSTM-TL卫星降水降尺度模型,同时采用SHAP(SHapley Additive exPlanations)方法对环境因子进行了可解释分析。结果表明:本文建立的卫星降水降尺度模型实现了500m空间分辨率的降水估算,其决定系数(R2)达0.82,较基础模型及CNN-TL、LSTM-TL模型分别提升了10.8%、22.4%和43.8%,显著提高了黄河上游地区降水估算精度;地表温度(LST)对模型预测结果的贡献最大,蒸散发(ET)次之,低海拔地区ET的负向贡献相对较为突出,高海拔区域LST的正向贡献更为明显。研究成果可为黄河上游水资源管理及干旱监测提供技术支撑。

     

    Abstract: To improve the spatial resolution of satellite precipitation in the Upper Yellow River Basin, a CNN-LSTM model was constructed by integrating a Convolutional Neural Network (CNN) to extract spatial features from environmental factors and a Long Short-Term Memory (LSTM) network to capture the temporal dependencies of precipitation processes. Transfer learning (TL) was then introduced to the CNN-LSTM base model to establish a CNN-LSTM-TL satellite precipitation downscaling model. Additionally, the SHAP (SHapley Additive exPlanations) method was applied to interpret the contributions of environmental factors. The results showed that the proposed satellite precipitation downscaling model achieved precipitation estimation at a spatial resolution of 500 m, with a coefficient of determination (R2) of 0.82, representing improvements of 10.8%, 22.4%, and 43.8% compared with the CNN-LSTM, CNN-TL, and LSTM-TL models, respectively, thereby significantly enhancing precipitation estimation accuracy in the Upper Yellow River Basin. Land surface temperature (LST) contributed most to the model predictions, followed by evapotranspiration (ET). The negative contribution of ET was more pronounced in low-altitude areas, whereas the positive contribution of LST was more evident in high-altitude regions. The proposed approach provides technical support for water resources management and drought monitoring in the Upper Yellow River Basin.

     

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