报告人：Ben DeVries

　　邀请人：柏延臣 教授

　　时间：2017年12月23日9:00

　　地点：北师大生地楼180会议室

　　主要内容：

　　Water is a critical component of all terrestrial ecosystems, with surface water playing a particularly important role in a range of ecosystem processes. The recent launch of the Sentinel-1 and Sentinel-2 satellite constellations and the release of their data to the public presents an opportunity to complement Landsat data in monitoring surface water at high spatial and temporal resolutions. New algorithms that are able to exploit synergies between optical (Landsat and Sentinel-2) and SAR (Sentinel-1) data streams are needed to establish consistent records of surface water inundation over time. Research over several wetland sites and recent flood emergency situations shows that fusion of Landsat and Sentinel-based surface water estimates allows for the quantification of surface water dynamics at both high spatial and temporal resolutions. Despite the promise of this "virtual constellation" of medium resolution satellites, temporal gaps still remain, generating uncertainties in estimates of surface water dynamics over time. Advancing these optical-SAR surface water methods and data products therefore warrants consideration of future Earth Observations missions, such as the planned joint NASA-ISRO NISAR SAR mission, to improve their sensitivity to highly dynamic ecosystems.

　　专家简介：

　　Ben DeVries is a Post-Doctoral Research Associate at the Department of Geographical Sciences, University of Maryland. He has a background in Remote Sensing and is currently developing algorithms for detecting and quantifying surface water inundation at fine spatial and temporal resolutions using multi-source satellite data. Ben earned his Ph.D. in 2015 at Wageningen University in the Netherlands, where he studied forest dynamics in the tropics and developed novel methods using temporally dense Landsat time series data. He previously earned his M.Sc. in 2010 at Wageningen University, in which he researched the role of surface and sub-surface hydrology on carbon emissions in degraded tropical peatlands.