Estimation of Potential Evapotranspiration by Different Methods in Handan Eastern Plain, China

Potential evapotranspiration estimation is the foundation of water resources assessment. Based on the daily meteorological data during 2000-2005 of Linzhang Meteorological Station in Handan Eastern Plain, temperature-based Hargreaves method, radiation-based Priestley-Taylor method, and FAO Penman-Monteith method with comprehensive consideration of aerodynamics were used to estimate potential evapotranspiration. Correlations between monthly potential evapotranspiration and water surface evaporation were conducted. The results indicated that potential evapotranspiration calculated by Hargreaves method was the largest, while the potential evapotranspiration calculated by Priestley-Taylor method was the smallest. The seasonal potential evapotranspiration values for the three methods were summer > spring > autumn > winter. The correlation between potential evapotranspiration calculated by the FAO Penman-Monteith method and water surface evaporation during the same period was best (r=0.991). In contrast, Penman-Monteith method is more suitable for estimating the potential evapotranspiration in Handan Eastern Plain.