| Spatial-temporal distribution characteristics of drought in Guanzhong region of Shaanxi Province based on MOD16 products |
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| DOI：10.7606/j.issn.1000-7601.2016.01.36 |
| Key Words: MOD16 drought Spatial-temporal distribution CWSI Guanzhong region |
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| Abstract: |
| Based on MOD16 products and the method of crop water stress index, combined with meteorological station observations and MOD17 vegetation index information, this article analyzed the Spatial-temporal variation characteristics of drought in the Guanzhong region of Shaanxi Province during 2000—2013. The results showed that crop water stress index based on MOD16 products was consistent with the variation of soil relative humidity, and the correlation coefficient between them was significant (P<0.001). This relationship indicated that MOD16 products could be used to analyze the variation features in Guanzhong region. In addition, the crop water stress index had not been evenly distributed. In eastern and northern of Guanzhong regions, its value was high, suggesting relatively dry condition. Particularly, in the northeast of Guanzhong region and around Xi’an city, the crop water stress index was 0.795～0.832, reaching a heavy drought level. In the meantime, drought severity was becoming elevated. Furthermore, the crop water stress index had obvious monthly fluctuation variations, reaching its highest value of 0.7 in March to June and October to November. From March to June, heavy and severe drought events mainly occurred. Rather from October to November, light and medium drought events mostly took place. In Guanzhong region, the crop water stress index exhibited an increasing trend, after minimum and maximum values of 0.65 in 2003 and 0.8 in 2013, respectively. The area suffered light drought showed a trend of becoming reduced. However, areas with medium to severe drought were increased during 2000—2013. Moreover, temperature, precipitation and vegetation were closely related to crop water stress index. During the period with higher temperature and less precipitation, the crop water stress index was high, drought was likely to happen, and the normalized difference vegetation index was low. |
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