1. Monitoring the Drying Process Using Multi-Temporal AVHRR Data in 1990, Huaihe River Basin, China
- Author
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HIGUCHI, Atsushi, KONDOH, Akihiko, KISHI, Shinkichi, FUKUZONO, Teruki, and LI, Jiren
- Abstract
[ABSTRACT] Recent researches have shown that the combination of spectral vegetation indices (VIs) with thermal infrared observations may provide an effective method for parameterizing surface processes at large spatial scales. In this study, we tested a hypothesis that seasonal changes in the slope of VIs and surface temperature T_s derived from the satellite remote sensing are sensitive to drying processes of surface moisture status. Huaihe River Basin, which is the study area, is characterized by steep climatological gradient from southeast to northwest. Annual precipitation in the study area decreases from southeast to northwest. NOAA/AVHRR (Advanced Very High Resolution Radiometer) GAG (Global Area Coverage) data over the study area for the continuous 80 days after Meiyu (the name of rainy season from June to July, in China) of 1990 were used to derive VIs as well as T_s values, while meteorological data provided by NOAA GDS (Global Daily Summery) CD-ROM was used for analysis. After applying radiometric and geometric correction, we evaluated the slope and intercept, i.e. T_s versus VIs relationships (T_s/VIs). Results of this study are summarized as follows Seasonal changes in slope and intercept derived from T_s and VIs relations for agricultural fields correlate well to these of antecedent precipitation index (API). Moreover, It was clear that seasonal changes in T_s versus VIs relations were not only affected by seasonal changes of land surfaces moisture status, but also sensible to the effect of irrigation practice.
- Published
- 1997