【摘要】 应用NOAA-AVHRR多时段卫星遥感数据,以陕西省关中平原为研究区域,建立了条件植被温度指数干旱监测方法,讨论了植被指数和地表温度特征空间中冷边界和热边界的确定方法。通过气象网站的降水量资料验证了该研究区域1999年以来每年5月上旬的干旱监测结果,结果表明条件植被温度指数与降水量间的相关性随着累计时间的增加而降低,与最近月份降水量的相关性最好,证实了冷边界和热边界确定方法的合理性以及条件植被温度指数是一种可行的、近实时的干旱监测方法。更多还原

【Abstract】 This study is focused on developing appropriate methods for determining the "warm edge" and "cold edge" of vegetation temperature condition index(VTCI) drought monitoring approach.By integrating AVHRR’s land surface temperature(LST) and normalized difference vegetation index(NDVI) products,the edges’ determining methods were studied by using the multi-years’ composited LST and NDVI products in the given period of the first ten days of May from 1999 to 2003.The results show the "warm edge" can be determined by using multi-years’ maximum value composited LST and NDVI products in the given period.While,the "cold edge" can be(determined) by applying the combinations with the multi-years’ maximum value composited NDVI product and a minimum composited LST product.The minimum LST product was acquired by using the minimum value compositing technique to process each year’s maximum value composited LST products.Ground-measured precipitation data in Guanzhong Plain,Shaanxi Province of China were employed to validate the edges’ determining methods and VTCI approach.A linear correlation analysis was applied to study the correlation between precipitation and VTCI.There are positive correlations between precipitation and VTCI,the correlation coefficients between VTCI and cumulative precipitation in one or two periods of ten days interval are the highest.These results(indicate) that the edges’ determining methods are feasible,and VTCI is a close real-time drought monitoring(approach).更多还原