文摘
A drought is a period of a lack of precipitation in water-deficient areas, causing shortages in their water supply, whether atmospheric, surface, or ground water. Drought with long-duration and wide-area coverage often leads to serious social and economic losses. Consequently, drought monitoring and assessment have become a critical research topic in the area. There are a number of related studies on identifying drought with different types of data, but few aim at automatic drought tracking since drought regions are time variant. In this study, an automatic drought monitoring method is proposed based on drought region tracking. Firstly, drought regions are identified with drought indexes. A simulated annealing algorithm is then used to automatically track different drought regions in successive time intervals based on the area and location of different drought regions. Preliminary results of a case experiment indicate that the simulated annealing algorithm is suitable to be used in automatic monitors and able to achieve desirable tracking results. The proposed method based on the simulated annealing algorithm is effective for automatically monitoring the variation in drought characteristics such as the spatial extent.