| Based on field experiments, the change characteristic of CST(canopy surface temperature) and the correlation among CST and SWC(soil water content) in major growth stages(from jointing stage to grain-filling stage) of winter wheat were studied, and the empirical models on estimating SWC with CST as independent variable were established; by comparison among 9 different split window methods using NOAA/AVHRR data in regional scale(Handan district), the optimal retrieval method UL92 for CST in Handan was derived, and LST(land surface temperature) retrieved using UL92 in regional scale was applied in monitoring drought and crop growth on the basis of empirical models between CST and SWC.The research results showed, the same daily change characteristic among CST, air temperature and SST (soil surface temperature) of winter wheat under 5 different water treatments(full-fresh-water-irrigation; fresh-saving-water-irrigation; full-salty-water-irrigation; salty saving-water-irrigation; no-irrigation): the highest temperature at 14:00 and the relative lower temperature in the morning and evening. During major growth stages, the similar change dynamic characteristic exists among the above 3 temperatures: with air temperature increasing gradually, CST and SST also increase gradually, and the 3 temperatures increase at the highest rate in jointing stage and anthesis stage. But the differences in CST change are distinct for different water treatments and indicate that CST at 14:00 can reflect crop water condition as a indicator to saving water irrigation capacity. The similar change trend also exists in temperature difference between canopy-air(Tca) and land-canopy(Tlc) of winter wheat in different water treatments: the highest temperature difference at 14:00, but the values of temperature difference under different water treatments differ from each other: Tca<0, Tlc<0 mostly with the order of T(LST)0, Tlc>0 basically under no irrigation; the relative bigger fluctuation of Tea lies in the height of 50 cm above canopy at 14:00 between canopy-air temperature differences in three heights. From the above analysis, the Tea above canopy at 14:00 is the best indicator to crop water condition, which presents the support for application of canopy-air temperature differences in reflecting water condition of crop and soil in regional scale.The correlation between CST and SWC under different water treatments in field experiments was analyzed. The regression relationship results gave significant correlation of quadratic or cubic equations between CST and SWC and were different in different time and different soil layers, especially among different water treatments. The correlation between Tea in three heights and SWC under different water treatments was also studied and significant with quadratic or cubic regression equations basically, but there were the differences of correlation between Tea in different heights and SWC among different treatments. By comparison, Tea above canopy at 14:00 gave relative better correlation in different water treatments, which provided the experimental support for estimating SWC in regional scale usingregression models between Tea above canopy by field experiments and SWC combing with remote sensing data.The experimental results in the village scale showed: it was appropriate to establish respectively the regression models between CST, Tea and SWC according to growth stages of winter wheat, the regression results was better between Tea and SWC than between CST and SWC.By validating 9 split window methods by field experiments, UL92 can retrieve LST in Handan district more successfully than other retrieval methods, and especially from the beginning of booting stage, the retrieved LST was approximate to CST. During the major growth periods from jointing to g-ain-filling stage, the mean error -0.27℃ and standard error 2.66℃ were deriv...
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