高级检索

    顾及时空相关性的闽浙赣地区多源降水融合

    Multi-source precipitation fusion in the Fujian-Zhejiang-Jiangxi region considering spatiotemporal correlations

    • 摘要: 多源降水融合技术是精准估算降水时空分布的重要手段,但常规融合方法难以充分考虑降水的空间局部相关性和时间依赖性以再现降水的空间分布格局。该研究选择3套卫星降水产品(IMERG,CMORPH和GSMaP)和站点观测数据,构建三维卷积神经网络(three-dimensional convolutional neural network,3DCNN)和卷积长短期记忆神经网络(convolution long short term memory neural network,ConvLSTM)集成的时空深度学习融合模型(3DCNN-ConvLSTM),通过深度挖掘降水的时空变化特征,实现降水数据的精确估计。结果表明,在日尺度上,3DCNN-ConvLSTM融合降水的性能显著优于原始卫星降水产品,融合后的相关系数和克林-古普塔效率系数分别提高至0.679和0.64,均方根误差较融合前降低11.7%~24.4%,平均绝对误差降幅为9.3%~20.7%,且针对不同强度降水事件的捕捉精度更高; 在月尺度上,各月降水性能得到不同程度的改善,其中高降水月份提升更显著;在空间尺度上,融合模型校正了原始降水产品在空间上的高估现象,在不同地形上表现出最高相关性及最小误差。与其他融合模型相比,3DCNN-ConvLSTM在提升降水数据精度方面表现更出色。总之,考虑了降水时空相关性的多源降水融合模型,能够有效提升闽浙赣地区降水数据质量,在多源降水融合领域有一定应用价值。

       

      Abstract: The multi-source precipitation fusion technique serves as an important method for accurately estimating the spatiotemporal distribution of precipitation. However, conventional techniques fail to adequately incorporate the spatial local correlation and temporal dependence of precipitation, thus limiting their ability to reproduce its spatial distribution patterns. To overcome this limitation, this study first selected three satellite precipitation products (IMERG, CMORPH, and GSMaP) and ground-based observation data. Subsequently, it constructed a deep learning-based spatiotemporal precipitation fusion model (3DCNN-ConvLSTM) that integrates a three-dimensional convolutional neural network (3DCNN) and a convolutional long short-term memory neural network (ConvLSTM). The integrated model achieves accurate precipitation estimation by deeply extracting its spatiotemporal variations. The results indicate that at the daily scale, the proposed 3DCNN-ConvLSTM significantly outperformed the original satellite precipitation products in precipitation fusion. The superiority was evinced by the following metrics: the correlation coefficient and Kling-Gupta efficiency coefficient increased to 0.679 and 0.64, while the root mean square error (RMSE) and the mean absolute error (MAE) decreased by 11.7% to 24.4% and 9.3% to 20.7%, respectively. Besides, the model exhibited enhanced accuracy for detecting precipitation events of different intensities. At the monthly scale, the model improved estimation accuracy of monthly precipitation to different degrees, with the more significant improvements occurring in high-precipitation months. At the spatial scale, the integrated model corrected the spatial overestimation of the original satellite precipitation products, yielding the highest correlations and the smallest errors over varying terrains. Compared with other fusion models, the 3DCNN-ConvLSTM presented superior performance in improving precipitation data accuracy. In conclusion, the multi-source precipitation fusion model considering the spatiotemporal correlations can effectively improve the quality of precipitation data in the Fujian-Zhejiang-Jiangxi region, offering practical value in the field of multi-source precipitation fusion.

       

    /

    返回文章
    返回