采用MODIS的1 km×1 km分辨率数据,以我国黑龙江为研究区,对基于植被指数的植被状态指数(IVC)、基于地表温度的温度状态指数(ITC)和基于植被指数-地表温度特征空间的植被温度状态指数(IVTC)与10 cm,20 cm土壤相对湿度、降水量的关系、3种指数监测结果及其相互关系进行了对比分析.结果表明:IVTC相对于ITC,IVC更适于反映土壤湿度的变化,对浅层土壤湿度更加敏感;IVTC相对于ITC,IVC对降水更敏感,与监测时段的降水和前期总体降水都密切相关;在生长季早期,IVTC和ITC用于干旱监测的适用性明显优于IVC;不同区域间,IVTC的可比性较好,IVC和ITC则较差;IVTC所反映的地表温度信息对干旱的直接指示作用最强,所反映的植被信息对干旱的直接指示作用较弱.%As a frequent natural hazard, drought causes the heaviest damage to daily life and ecological environment among all natural disasters.The large scale and dynamic drought monitoring has been frontier and hot topic in the global climate change and food security research.Satellite remote sensing is the main method of obtaining distributed information of the land surface.However, the applicability of a drought monitoring method varies by region and period.So it's necessary to inspect and evaluate the drought monitoring method to ensure the validity and accuracy in drought monitoring.Vegetation index based IVC, land surface temperature based and Surface Temperature-Normalized Difference Vegetation Index space (Ts-INDv space) based are compared to analyze and evaluate their characteristics and applicability in drought monitoring.The MODIS 16-day NDVI (MOD13A2) and 8-day Ts (MOD11A2) provided at 1 km spatial resolution as a gridded level-3 product in the Sinusoidal projection are used, and the Heilongjiang Province, the main food production area in China, is chosen as the study area.The monitoring period is from 9 May to 9 June of the year 2000 to 2008.The correlation between IVC, ITC, IVTC and relative soil moisture in 10 cm and 20 cm depth, the correlation between IVC, ITC, IVTC and the precipitation in the satellite monitoring period and the cumulative precipitation in the last 1-, 2-,3-, 4-period time scales, the difference and the relationship between IVC, ITC, IvTC are analyzed.Significant linear correlation is found between IVTC and the relative soil moisture in 10 cm and 20 cm depth, especially for the 10 cm depth.The correlation between IVTC and relative soil moisture is obviously better than that between ITC, IVC and the relative soil moisture.So, it can be judged that IVTC may mirror the soil moisture better than IVC and ITC, and is more sensitive to shallow soil moisture.IVTC is also found linearly correlated with precipitation in current monitoring period, as well as the cumulative precipitation in the last 1-, 2-, 3-, 4-period timescales.The correlations are better than those between ITC, IVC and precipitation as well as corresponding cumulative precipitation, which show that IVTC is more sensitive to precipitation than IVC and ITC, and is closely related to not only current precipitation but also past cumulative precipitation.In the early growing season, IVTC and ITC are applicable in drought monitoring, while the fractional IVC cover is too low to monitor drought.It is difficult to compare the drought among different areas with IVC and ITC, while based on the energy conservation principle, combining the INDV and Ts, IVTC can reflect soil moisture better and is comparable in different areas.Furthermore, the land surface temperature implied by IVTC gives more direct hint of drought than the INDV implied especially on the grassland, then in the crop land, brush land and forest land in sequence.
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