| Comparison and application of remote sensing monitoring indexes of drought in Guanzhong Plain |
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| DOI：10.7606/j.issn.1000-7601.2018.06.30 |
| Key Words: NIR-Red space comparison of several drought indexes SMMI drought monitoring Guanzhong Plain |
| Author Name | Affiliation | | LIU Ying | College of Geomatics, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054 | | LU Yang | College of Geomatics, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054 | | Li Yao | College of Geomatics, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054 | | YUE Hui | College of Geomatics, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054 |
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| Abstract: |
| By using MODIS data from May 2000 to May 2016, constructing the NIR-Red space, and collecting the Perpendicular Drought Index (PDI), Modified Perpendicular Drought Index (MPDI), Soil Moisture Monitoring Index (SMMI) and Modified Soil Moisture Monitoring Index (MSMMI),we studied the validity of these four indexes and the correlation of them with the measured soil moisture data. Then, the spatial and temporal distribution characteristics of drought in Guanzhong plain was assessed based on SMMI that had the highest precision.The results showed that: (1) There was a negative correlation between PDI, MPDI, SMMI and MSMMI with measured soil moisture in the top 10 cm layer with R2, coefficient of correcation of 0.60,0.40,0.64, and 0.40, respectively. It was suggested that all four indexes could be used as drought indicators while SMMI was slightly better than the others. (2) The drought conditions in the eastern, central, and western regions of Guanzhong plain were more severe while soil water content was relatively higher in the southwestern area. There was a significant inter-annual fluctuation in drought of Guanzhong plain. (3)There was a positive correlation between SMMI and average monthly temperature in 75.66% of the total area but a negative correction of SMMI with monthly precipitation in 74.34% of the area. The significance test showed that 27.36% and 17.26% of that are at P<0.1 level, respectively, indicating that precipitation and temperature were not the major factors causing the changes in drought. |
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