Detection of Land Cover Change and Drought Trend Using Brightness Temperature and Microwave Emission

Drought and the change in land cover are currently among the largest issues affecting the world, threatening to bring huge amounts of economic loss every year. The purpose of this paper is to determine the potential in using microwave brightness temperature and emissivity data to monitor previous droughts and land cover changes. It is known that precipitation and soil moisture provide drought information based on different data sets. Using microwave radiation at various frequencies, satellites sensors such as Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and Special Sensor Microwave Imager (SSMI) have been collected to formulate the emissivity around the globe for the last few decades. Each satellite has gathered data at multiple frequencies. In this study, we focus on the lower frequencies because the signal is more sensitive to surface properties. The Emissivity Microwave Polarization Difference Index (EMPDI) from emissivity data is computed by vertical and horizontal emissivity value. The global EMPDI values for an entire month are then placed in contrast with an independent indicator such as precipitation. Moreover, a drought severity test is performed using techniques that previously were deployed on precipitation data to investigate the potential of using microwave observations in drought monitoring, directly. Finally, the limitation of using such information is investigated.