Drought monitoring analysis based on FY-3/MERSI data

In the present study, drought monitoring in rain-fed agricultural regions of eastern Gansu was comparative analyzed using the 250 m resolution data of MERSI which carried by the Chinese new generation of meteorological satellite FY-3 with three drought remote sensing monitoring models combined with precipitation, temperature and meteorological drought data of the same periods. The drought monitoring models based on FY-3/MERSI data can objectively reflect space distribution and dynamical development of droughts. The drought monitoring models were obviously different. The drought monitoring models were significantly correlated with soil relative moisture in 0-10 cm, 0-20 cm and 0-50 cm layer(P0.01). PDI was significantly negative correlated with the soil relative moisture, whereas VSWI and MSAVI were significantly positive correlated with soil relative moisture. MSAVI had a more significant correlation with soil relative moisture in 0-10 cm than VSWI and PDI although the correlation coefficient of all these 3 models were more than 0.84; PDI was more significantly correlative with soil relative moisture in 0-20 cm and 0-50 cm than VSWI and MSAVI although the correlation coefficient of all these 3 models were more than 0.82. The soil relative moisture in 0-20 cm was more significantly correlative with PDI and MSAVI than that in 0-50 cm although all of the correlation coefficient were more than 0.83; The soil relative moisture in 0-10 cm was more significantly correlated with VSWI than that in 0-20 cm and 0-50 cm although all of the correlation coefficient were more than 0.83. Briefly, PDI was most sensitive to drought variation among these three monitoring models which was most suitable for regular operation over this region, especially in spring.