H197-0021
Using CYGNSS to Monitor Flood in Southern China

Wednesday, 16 December 2020
Poster
Can Wang, Zhejiang University, Zhejiang University/University of Illinois at Urbana-Champaign Institute, Hangzhou, China and Shurun Tan, Zhejiang University, Zhejiang University/University of Illinois at Urbana-Champaign Institute, Haining, China
Abstract:
Heavy rainfall has occurred in southern China in summer 2020, resulting in severe floods in many places. China's Poyang Lake, Yangtze River and Huaihe River basins have all issued flood warnings. NASA's Cyclone Global Navigation Satellite System (CYGNSS) mission is a constellation of 8 small satellites used to improve the accuracy of hurricane forecasting through the global navigation satellite system-reflectivity (GNSS-R) technique. Since CYGNSS has very short revisit periods and very high sensitivity to surface water, it has the potential to be used for close-to-realtime flood monitoring and support rescue in food incurred disasters.

This paper aims to develop an effective method to monitor floods globally using the GNSS-R technique and to apply the method to monitor the current flood in southern China using the CYGNSS data. Special focus is on choosing the site and time specific thresholds of the surface reflectivity to detect floods. The CYGNSS data used in this study were from level 1, version 2.1, available via https://podaac.jpl.nasa.gov/. The Poyang Lake Basin is chosen to test our algorithm. The surface reflectance before and after the flood are analyzed. The potential of using GNSS-R technique to monitor the water level dynamics during floods are also examined.

Keywords: GNSS-R; CYGNSS; Flood Monitoring; Surface Reflectance; Threshold.