Articles | Volume 374
Proc. IAHS, 374, 35–40, 2016
https://doi.org/10.5194/piahs-374-35-2016
Proc. IAHS, 374, 35–40, 2016
https://doi.org/10.5194/piahs-374-35-2016

  17 Oct 2016

17 Oct 2016

Rainfall as proxy for evapotranspiration predictions

Bruno Collischonn1 and Walter Collischonn2 Bruno Collischonn and Walter Collischonn
  • 1Agencia Nacional de Aguas, Brasilia, 70610-200, Brazil
  • 2Instituto de Pesquisas Hidraulicas, Porto Alegre, 91501-970, Brazil

Abstract. In this work, we evaluated the relationship between evapotranspiration and precipitation, based on the data recently made available by the Brazilian Meteorological Institute. ETP tend to be lower in rainy periods and vice-versa. This relationship was assessed both in physical and statistical ways, identifying the contribution of each explaining variable of ETP. We derived regression equations between monthly rainfall and ETP, which can be useful in studies where ETP time series are not available, such as reservoir design, irrigation management and flow forecast.

Download
Short summary
Hydrometerologial data in Brazil is becoming increasingly more accessible in recent years, but data gaps still exist in many regions. In our work, we tested some statistical ways to explore the existing data and fill gaps in evaporation estimates, based on the assumption that evaporation and precipitation are inversely related. This could be useful for extending evaporation series into the past, for example for hydropower reservoir planning and flow forecast.