Characterization and Space-Time Downscaling of the Inundation Extent over the Inner Niger Delta Using GIEMS and MODIS Data

The objective in this work is to develop downscaling methodologies to obtain a long time record of inundation extent at high spatial resolution based on the existing low spatial resolution results of the Global Inundation Extent from Multi-Satellites (GIEMS) dataset. In semiarid regions, high-spatial-resolution a priori information can be provided by visible and infrared observations from the Moderate Resolution Imaging Spectroradiometer (MODIS). The study concentrates on the Inner Niger Delta where MODIS-derived inundation extent has been estimated at a 500-m resolution. The space-time variability is first analyzed using a principal component analysis (PCA). This is particularly effective to understand the inundation variability, interpolate in time, or fill in missing values. Two innovative methods are developed (linear regression and matrix inversion) both based on the PCA representation. These GIEMS downscaling techniques have been calibrated using the 500-m MODIS data. The downscaled fields show the expected space-time behaviors from MODIS. A 20-yr dataset of the inundation extent at 500 m is derived from this analysis for the Inner Niger Delta. The methods are very general and may be applied to many basins and to other variables than inundation, provided enough a priori high-spatial-resolution information is available. The derived high-spatial-resolution dataset will be used in the framework of the Surface Water Ocean Topography (SWOT) mission to develop and test the instrument simulator as well as to select the calibration validation sites (with high space-time inundation variability). In addition, once SWOT observations are available, the downscaled methodology will be calibrated on them in order to downscale the GIEMS datasets and to extend the SWOT benefits back in time to 1993.

[1]  Filipe Aires,et al.  Remote sensing of global wetland dynamics with multiple satellite data sets , 2001 .

[2]  M. Goldberg,et al.  Derivation of 30-m-resolution water maps from TERRA/MODIS and SRTM , 2013 .

[3]  D. Lettenmaier,et al.  Measuring surface water from space , 2004 .

[4]  F. Aires,et al.  Global inundation dynamics inferred from multiple satellite observations, 1993–2000 , 2007 .

[5]  Robert P. Bukata,et al.  Satellite Monitoring of Inland and Coastal Water Quality: Retrospection, Introspection, Future Directions , 2005 .

[6]  David M. Legler,et al.  Empirical Orthogonal Function Analysis of Wind Vectors over the Tropical Pacific Region , 1983 .

[7]  Filipe Aires,et al.  Independent component analysis of multivariate time series: Application to the tropical SST variability , 2000 .

[8]  C. Prigent,et al.  Interannual variations of river water storage from a multiple satellite approach: A case study for the Rio Negro River basin , 2008 .

[9]  Rodrigo Abarca-Del-Rio,et al.  Does Lake Titicaca still control the Lake Poopó system water levels? An investigation using satellite altimetry and MODIS data (2000–2009) , 2012 .

[10]  Yong Wang,et al.  An efficient method for mapping flood extent in a coastal floodplain using Landsat TM and DEM data , 2002 .

[11]  Steven P. Neeck,et al.  Surface Water and Ocean Topography (SWOT) mission , 2012, Remote Sensing.

[12]  John F. Galantowicz,et al.  High-resolution flood mapping from low-resolution passive microwave data , 2002, IEEE International Geoscience and Remote Sensing Symposium.

[13]  François Delclaux,et al.  FLOOD MAPPING INFERRED FROM REMOTE SENSING DATA , 2011 .

[14]  G. R. Brakenridge,et al.  Global mapping of storm surges and the assessment of coastal vulnerability , 2013, Natural Hazards.

[15]  Filipe Aires,et al.  Land Surface Microwave Emissivities over the Globe for a Decade , 2006 .

[16]  Jean-François Crétaux,et al.  Investigations on Aral Sea Regressions from Mirabilite Deposits and Remote Sensing , 2009 .

[17]  F. Aires,et al.  Interannual variability of surface water extent at the global scale, 1993–2004 , 2010 .

[18]  I. Jolliffe.  Principal Component Analysis , 2002 .

[19]  Filipe Aires,et al.  Temporal interpolation of global surface skin temperature diurnal cycle over land under clear and cloudy conditions , 2004 .

[20]  C. Prigent,et al.  Surface freshwater storage and dynamics in the Amazon basin during the 2005 exceptional drought , 2012 .

[21]  A. Tarantola.  Inverse problem theory : methods for data fitting and model parameter estimation , 1987 .

[22]  Javier Tomasella,et al.  Satellite-based estimates of groundwater storage variations in large drainage basins with extensive floodplains , 2011 .

[23]  Filipe Aires,et al.  A Long-Term, High-Resolution Wetland Dataset over the Amazon Basin, Downscaled from a Multiwavelength Retrieval Using SAR Data , 2013 .

[24]  T. Sakamoto,et al.  Detecting temporal changes in the extent of annual flooding within the cambodia and the vietnamese mekong delta from MODIS time-series imagery , 2007 .

[25]  Yoram J. Kaufman,et al.  Remote sensing of suspended sediments and shallow coastal waters , 2003, IEEE Trans. Geosci. Remote. Sens..

[26]  F. Aires,et al.  Changes in land surface water dynamics since the 1990s and relation to population pressure , 2012 .

[27]  Filipe Aires,et al.  Remote sensing from the infrared atmospheric sounding interferometer instrument 1. Compression, denoising, and first-guess retrieval algorithms , 2002 .

[28]  J. Crétaux,et al.  Hydrology and Earth System Sciences Evaluation of the Isba-trip Continental Hydrologic System over the Niger Basin Using in Situ and Satellite Derived Datasets v. Pedinotti Et Al.: Isba-trip Continental Hydrologic System over the Niger Basin , 2022 .