Author Affiliations
1School of History Culture and Tourism, Shaanxi University of Technology, Hanzhong 723000, Shaanxi, China2Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China3College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, Chinashow less
Fig. 1. Geographical location, elevation and distribution of meteorological stations in the Beijing-Tianjin-Hebei region
Fig. 2. Flow charts of comprehensive drought monitoring model
Fig. 3. R2 and Bias variations after downscaling of TRMM annual scale
Fig. 4. Observed precipitation vs. downscaling TRMM precipitation (monthly scale)
Fig. 5. R2 and Bias variations after downscaling of TRMM monthly scale
Fig. 6. Monthly precipitation in the Beijing-Tianjin-Hebei region during 2007-2016
Fig. 7. Scatter plots and correlation coefficient of R values between SPI-3 and CDI index in each month from 2007 to 2016
Fig. 8. Scatter plots and correlation coefficient of R values between drought-affected crop area and CDI, VCI, TCI from 2007 to 2016
Fig. 9. Scatter plots and correlation coefficient of R values between accumulative CDI and standardized unit yield of crop in the growing period (March-October) from 2007 to 2016
Fig. 10. Scatter plots and goodness-of-fit between CDI and CI in growing period of main crops (March-October) from 2007 to 2016
Fig. 11. Drought map of Beijing-Tianjin-Hebei region in 2016 based on monitored CDI index
Fig. 12. Histogram plot of CDI of the Jing-Jin-Ji region in crop (winter wheat and maize) growing period (March-October) from 2007 to 2016
月份 | 拟合方程 | R2 |
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3 | | 0.522 | 4 | | 0.738 | 5 | | 0.732 | 6 | | 0.728 | 7 | | 0.744 | 8 | | 0.762 | 9 | | 0.703 | 10 | | 0.820 |
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Table 1. Monthly scale regression equation from March to October in 2007-2016
干旱等级 | 特旱 | 重旱 | 中旱 | 轻旱 | 无旱 |
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CDI | <-2 | [-2, -1) | [-1, 0) | [0, 1) | ≥1 |
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Table 2. Classification of drought grades
季节 | K值 | CDI趋势 | 干旱趋势 | 面积/103 km2 | 比例/% |
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春 | <0 | ↓ | ↑ | 199.27 | 93.12 | 0 | - | - | 4.58 | 2.14 | >0 | ↑ | ↓ | 10.14 | 4.74 | 夏 | <0 | ↓ | ↑ | 33.06 | 15.45 | 0 | - | - | 4.39 | 2.05 | >0 | ↑ | ↓ | 176.54 | 82.5 | 秋 | <0 | ↓ | ↑ | 102.16 | 47.74 | 0 | - | - | 4.52 | 2.11 | >0 | ↑ | ↓ | 107.31 | 50.15 | 冬 | <0 | ↓ | ↑ | 175.81 | 82.16 | 0 | - | - | 4.54 | 2.12 | >0 | ↑ | ↓ | 33.64 | 15.72 |
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Table 3. Statistics of CDI index changes in the four seasons of 2007-2016