Validation of a soil moisture model for pasture in Rondônia, Brazil.
Luciana
Rossato, DMA-CPTEC-INPE, rossato@cptec.inpe.br
(Presenting)
Regina
Célia dos Santos
Alvalá, DMA-CPTEC-INPE, regina@cptec.inpe.br
Javier
Tomasella, DMA-CPTEC-INPE, javier@cptec.inpe.br
Rossato (2002) developed water balance model for estimating soil moisture in Brazil based on the supposition that soil moisture is a function of water storage in the soil, available for the plants, the precipitation and the potential evapotranspiration of the vegetative cover. To estimate the mean monthly water balance for the period 1971 - 1990, the pedological and meteorological information was interpolated by using different spatial and temporal resolutions. The objective of this study is to validate the soil moisture model using the field data obtained during the LBA experiment. The daily data of the soil water storage were collected at Fazenda Nossa Senhora (10º45'S e 62º22'W), Ji-Paraná, Rondônia, Brazil, during the period 2000 - 2002. Based on this data, the mean monthly soil water storage for the experimental location was estimated and compared with the model results. The variation curve of the soil water storage estimated by the model and the field observation are quite similar. The correlation coefficients between the model results and the observation for the year 2000, 2001, and 2002 were 0.91, 0.88 and 0.94, respectively. Although the correlation coefficient for the year 2001 was not very high, one can conclude that the model estimates were representative of the observed soil moisture storage for the region and the period of this study.