Monitoring the impacts of waterlogging on winter wheat using high spatial resolution satellite data

Waterlogging, including flooding, is one of the serious agricultural disasters for winter wheat in the middle and lower reaches of the Yangtze River region, especially during the spring. It's of great practical value to discriminating the impact of waterlogging and flooding on winter wheat efficiently in the field. In this study, we combined the field campaign and satellite remote sensing data to discriminate the impact of waterlogging and flooding on winter wheat during the growing stages in the spring. The field experiment was carried out with three treatments, i.e., waterlogging (WL), flooding (FL)(waterlogging with 3 cm water layer above the ground) and contrast (CK), and two varieties, i.e., YM14 and YM18. The phenological stages includes seeding and tillering (ST) from 7 to 27 January and jointing and booting (JB) from 12 March to 1 April, respectively. For each treatment, three samples with an area of 0.25 m(2) were randomly determined and collected. High resolution satellite data, i.e., WorldView2, Pleiades and SPOT were also obtained. We proposed a method to calibrate the collection of high resolution remote sensing data. We used a measurement, namely the M, to differentiate the different waterlogging treatments. The results showed that the yield of winter wheat under different treatments for both varieties in ST and JB had significant differences. It showed that the flooding treatment could be discriminated from its CK and waterlogging treatment for YM14, and the waterlogging treatment of YM18 could be discriminated from its CK 16 days after ST treatment. The treatment in ST showed more lasting impacts on both YM14 and YM18. Compared with ST, the treatments in JB had more severe impacts on winter wheat growth. The flooding treatment of YM14 was differentiable from its CK and waterlogging treatment before the end of JB treatment, earlier than YM18. We concluded that both of the treatments in ST and JB periods had adverse impacts on YM14 and YM18, especially during ST period.