• Proceedings of the Korea Water Resources Association Conference
• /
• 1983.07a
• /
• pp.61-70
• /
• 1983

• Environmental Engineering Research
• /
• v.17 no.3
• /
• pp.175-176
• /
• 2012

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.57 no.1
• /
• pp.73-80
• /
• 2015

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 1997.10a
• /
• pp.40-43
• /
• 1997

• Water for future
• /
• v.44 no.2
• /
• pp.15-20
• /
• 2011

• Proceedings of the Korea Water Resources Association Conference
• /
• 1995.05a
• /
• pp.295-300
• /
• 1995

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.23 no.1
• /
• pp.75-85
• /
• 1981

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.12 no.4
• /
• pp.2138-2144
• /
• 1970

• Proceedings of the Korea Water Resources Association Conference
• /
• 2002.05b
• /
• pp.823-828
• /
• 2002

• Water Engineering Research
• /
• v.5 no.4
• /
• pp.185-193
• /
• 2004

Estimates of annual actual evapotranspiration are needed in water balance studies, water resources management projects, and many different types of hydrologic studies. This study validated a set of 5 empirical equations of estimating annual actual evapotranspiration with climate data on 11 watersheds, and evaluated the further applicability of these forms in estimating annual runoff on watershed level. Five empirical equations generally overestimated annual evapotranspiration, with relative errors ranging $3.3\%$ to $47.2\%$. The results show that Schreiber formula can be applicable in determining annual evapotranspiration in sub-humid region that is classified by aridity index, while Zhang equation gave better results than the remaining methods in humid region. The mean differences for annual evapotranspiration bias over 11 watersheds are Zhang, Schreiber, Budyko, Pike, and Ol'dekop formula from lowest to highest. The empirical equations provide a practical tool to help water resources managers in estimating regional water resources on ungauged large watershed.