A simple formula for estimating evaporation rates in various climates, using temperature data alone

摘要: The Penman formula for the evaporation rate from a lake is simplified to following: E0=700Tm/(100−A)+15(T−Td)(80−T)(mmday−1) where Tm = T + 0.006h, h elevation (metres), mean temperature, A latitude (degrees) and Td dew-point. Values given by this typically differ measured values about 0.3 mm day−1 annual means, 0.5 monthly 0.9 week 1.7 day. applies over wide range of climates. Monthly term (T − Td) can be obtained either an empirical table or following relationship, provided precipitation at least 5 month−1 4°C: (T−Td)=0.0023h+0.37T+0.53R+0.35Rann−10.9°C where R daily temperature Rann difference between temperatures hottest coldest months. Thus estimated simply elevation, maximum minimum temperatures.