A review of remote sensing in flood assessment

Flood is defined as water that temporarily submerges land. In the United States, flood is being considered as an event only if it last over 72 hours, but the time frame is much longer in the Europe. The information of water bodies is an important source when examining floods. However, this data is not always available or accurate by traditional survey since water surface changes frequently. Remote Sensing provides an alternative method to traditional survey with lower cost and much frequent revisit cycles. Some sensors have very fine spatial resolution but relative long revisit circle; while some fine temporal resolution satellites are not able to provide spatial information in detail. This paper provides a brief review and comparison of major optical and Radar satellite sensors which are currently adopted in flood assessment. Result indicated that both optical sensors and Radar systems play important roles in flood assessment. Although many agencies use Radar or optical data independently when ding flood assessment, the potential of combining data from both systems is huge.