A Schematic Equivalent Topography Model of the Lower Paraná Basin based on Satellite Estimations and a Simulation Model

MERCEDES SALVIA; MARIANO FRANCO; FRANCISCO MATIAS GRINGS; PAOLO FERRAZZOLI; CINTIA BRUSCANTINI; HAYDEE KARSZENBAUM

San Francisco

Congreso; American Geophysical Union fall meeting 2015; 2015

AGU ( American Geophysical Union)

p { margin-bottom: 0.1in; line-height: 120%; }Flooding is a major concern in the Plata Basin. Inparticular, Paraná River has a long and wide floodplain, which hasbeen settled and cultivated. Losses due to floods in Argentina duringthe 1983, 1992, 1998, 2007 and 2009-2010 floodings exceeded US$1billion each. Therefore, providing information about the basinhydrologic condition in a systematic way is critical to the regionaleconomies and society. In particular, monitoring basin fluvialwetlands? flood-drought cycles is of extreme importance. Theseecosystems extend along the Paraná-Paraguay axis and have highlydynamic exchanges of water with the river, with large annual andinterannual variations. Thus, both floodplain water level and floodedarea become relevant proxies for the total volume of water inside thefloodplain. Moreover, the dynamics of these variables will be a rawindicator of floodplain overall hydrological behavior. Therefore,estimating these variables in a systematic way using remote sensingdata, it is possible to constrain the outputs of hydrologicalforecast models. The aim of this work is to construct an equivalenttopography schema that can be incorporated to forecast and alertmodels of the basin. This is approached in three successive steps.First, we implement a methodology to estimate flooded area and waterlevel inside the floodplain, based on active and passive microwavesatellite data and a surface emissivity model. Then, we study thebehavior of the flooding and low water phases through the analysis ofthe relationship between flooded area fraction and water level insidethe floodplain obtained in the first step and between flooded areafraction and water level in adjacent water bodies obtained fromhydrometric gauges and microwave altimetry. Finally, from theobserved dynamics and a topographic simulation model we propose aschematic equivalent topography of the floodplain that represents thesimplest topography that can explain the water dynamics observedduring flooding events (See Figure 1). In summary, the approach used on this work allowsfor the analysis of current hydrological condition in terms of itslocation in the flooded area vs water level diagram, and the posingof different possible future flooding scenarios, which would beuseful for flooding forecast and alert.