以遥感为基础的干旱监测方法研究进展

Remote Sensing-based Drought Monitoring Approach and Research Progress

总结了目前广泛应用的气象监测模型和基于遥感数据的干旱监测模型,将目前的遥感监测方法分为植被状态监测方法、微波土壤水分监测方法、热红外遥感监测方法和基于能量平衡的遥感监测方法进行综述,深入分析了基于遥感数据的监测方法的特点、适用条件和存在的问题。通过综述基于多源数据的干旱综合监测模型,对未来干旱监测方法的发展方向进行研究和探讨,指出集成多源数据的干旱综合监测模型是解决复杂的干旱监测问题的新方法。

Drought is a serious natural disaster. It is doing increasingly damage to the human environment as the drought events occur more frequently. Real-time and effective drought monitoring is an effective means to reduce the losses caused by drought. Since the beginning of 20 th century, a lot of drought indices have been developed for monitoring the occurrence and variation of drought. Drought is a complex natural disaster. However, each drought index has its own advantages and weaknesses in drought monitoring. Almost all the drought indices are based on specific geographical and temporal scales; it is difficult to spread its applicability all over the world. Because of the meteorological drought indices using discrete, point-based meteorological measurements collected at weather station locations, the results have restricted level of spatial precision for monitoring drought patterns. Remote sensing technology provides alternative data for operational drought monitoring,with advanced temporal and spatial characteristics. However, additional information still needs to be incorporated so as to thoroughly explain the anomaly in vegetation caused by drought. Besides, to achieve a more accurate description of drought characteristics, drought intensity differences caused by vegetation type, temperature, elevation, manmade irrigation, and other factors under the same water condition must be considered.Therefore, effective drought monitoring indicator should both reflect soil moisture, vegetation condition and take into account vegetation type, temperature, and man-made factors leading to regional drought differences.Aiming at the problem mentioned above, the satellite based drought indices, and integrated meteorological and remote sensed drought indices was reviewed in our research. Firstly, this paper summarized the widely used drought monitoring models which were based on remote sensing data. The remote sensing drought monitoring approach was summarized by dividing it into four classes i.e. vegetation condition monitoring methods, microwave soil moisture monitoring methods, thermal infrared remote sensing monitoring methods and indices based on energy balance theory. The characteristics, application conditions and problems of the monitoring method which were based on remote sensing data and multi-source data(meteorological data, remote sensing data and biophysical data) were deeply analyzed. Then, the future development direction of drought monitoring model was studied and discussed by concluding comprehensive drought monitoring model which was based on multi-source data. Integrated multi-source data to construct comprehensive drought monitoring model was pointed out as a new approach to solve complex problems of drought monitoring. It can solve the inconsistency problems of space and temporal resolution from different data types. But the present study concluded that research on this area is still in the experimental and exploratory stage and need further improvement and development.