WATER RESOURCE MONITORING BASED ON EO DATA: GAINED EXPERIENCE AFTER 10 YEARS OF DRAGON PROGRAMME OVER THE YANGTZE MIDDLE REACHES: FROM ERS1 TO SENTINEL 1 AND FROM MERIS TO HJ1 AND PLEIADES

摘要

Water resources monitoring from space is an applicationrnof remote sensing under full development, with arrivingrnsatellite such as the Sentinels, and of course therndevelopment of inland applications of altimetry and thernfuture mission as SWOT. Since 10 years within thernframework of the DRAGON ESA MOST programme, arnmonitoring of Chines major fresh water lakes, Poyangrnand Dongting lakes on Yangtze reaches, is realizedrnexploiting large source of EO data. Thanks to EO datarnarchive exploitation, the covered period starts in 2000rnup to 2014, over these two core lakes, whereas, since arn2012, a similar approach is carried over the small lakesrnof Anhui Province. A key question is how to access tornconvenient satellite data with sufficient resource torninsure a high temporal frequency, ie ideally with aboutrn10 days of revisit. An opportunistic approach wasrnfollowed in order to insure this data access thanks to arnlarge ESA support, accessing Envisat and ESA TPM, asrnwell Chinese data. From 2004 to April 2012, ENVISATrnMedium resolution products, MERIS and ASAR WSMrndata, were the core of the monitoring system. Since thernlost of Envisat, the data exploited moved from MR tornHR (20-30 m), thanks to the access to large volume ofrnHJ1 images in 2012 and 2014, as well as coverage CSKrndata (30m) thanks agreement with ASI. The assimilationrnof these data is a fine preparation for the futurernexploitation of Sentinel1 and 2 dataset. Furthermore arnfirst Sentinel data have been exploited, less than 45 afterrnsatellite launch. In addition on most sensitive areas,rnsuch as the Poyang Lake natural Reserve (Jiangxi Pr)rnand Shenjing Lake (Anhui Prov.) a unique set of VHRrndata, Pleiades, Kompsat, have been exploited. Thernexpect strategy for the coming months and years will bernin a first period, the jointly exploitation of Sentinel 1rndata if the Chinese areas are rapidly integrated withinrnthe Sentinel 1 acquisition scheme, jointly with thernChinese HJ1AB data. In a second time HJ1AB datarnwould be substituted by the higher resolved and rich inrnterm of radiometry Sentinel2.