AMSRE AND PRELIMINARY SMOS OBSERVATIONS OF VEGETATED AREAS OF LA PLATA BASIN

H. KARSZENBAUM; F.GRINGS; M. SALVIA; DOUNA V.; V. BARRAZA; P. PERNA; M. BARBER; D. GONIADZKI; R.RAHMOUNE; P. FERRAZZOLI

Seattle

Workshop; 6th Aquarius/SAC-D Science meeting; 2010

NASA-CONAE-ESR

The La Plata Basin (LPB) (Spanish: Cuenca del Plata) (blue contour) is the name given to the 3,100,000 km hydrographical area that covers parts of Argentina, Brazil, Bolivia, Paraguay, and Uruguay. The precipitationsfalling within this area are collected by several rivers to finally reach the De La Plata River (main contributors Paraná and Uruguay rivers). One of the main issues is to monitor and predict the impact of global change andland use change (deforestation and replacement by intensive soy crop production) on regional weather, climate, hydrology and agriculture. More recently, extreme hydrological events (EHE) are affecting strongly differentregions within this basin. In addition, there is a very low coverage of hydrometric and meteorological stations. In this regard satellite missions constitute a main data contributor. This area is being addressed in a ESASMOS AO project and in a SACD-Aquarius NASA-CONAE project. The main goals of these projects are related with soil moisture retrieval within different vegetated areas (forest, wetlands, agriculture) with the aim ofgenerating precedent soil condition data for prediction models.1.This work analyzes AMSR-E signatures collected within the wide Gran Chaco Americano forest spanning the North-East of Argentina and parts of Bolivia and Paraguay. The total extent is more than 100 millionhectares. The events analyzed occurred in the semi-arid area (“Chaco semi-arido”). This area is covered by a continuous, deciduous forest. There are several species, but the dominating ones are “Quebracho coloradosantiagueño” (Schinopsis quebracho colorado) and “Quebracho Blanco” (Aspidosperma quebracho blanco). Although the forest is continuous, the biomass is moderate, typically ranging between 70–110 t/ha. After strongrain events, appreciable variations of polarization index (PI) at C band were observed. In addition, recent SMOS L band data were analyzed showing a better sensitivity to soil condition in the Chaco forest area.2. The lower part of Paraná River is subject to strong variations of water level, related to local rain events and the contribution of up-water of Paraná and Paraguay Rivers. Furthermore the terminal part of this sub-basinis influenced by the tidal regime of the La Plata estuary. AMSR-E signatures collected during a strong flooding event show significant variations of polarization indexes. Information about the water level in the river wasmade available by hydrometric stations. Using the absolute difference between vertically and horizontally polarized brightness temperatures (ΔT), radar inundation maps and a land cover map of the area, the fraction offlooded area was estimated as a function of time