关键词: 蒸发皿, 蒸发池, 水面蒸发, 模拟蒸发量, 干旱区, 平原水库

Abstract:

The surface evaporation of reservoirs in arid plain contributes great to the water losses of the reservoir. The measured evaporation by using the conventional evaporation pan is not in line with the actual evaporation characteristics of the reservoirs due to large water surface. Therefore, a small area evaporation test was conducted. The evaporation of the pond was measured through water level marking pin, and was compared with the pan evaporation. The results show that in actual evaporation, the evaporation of the pond fluctuates; the evaporation pan  has a 9.1% quicker evaporation speed than the surface evaporation, and the ratio of pan evaporation to the water surface evaporation increases at first and drops then; evaporation in pond is mainly affected by temperature, net radiation, wind speed and saturation vapor pressure difference. Since the water capacity of evaporation pan is small, the water heat capacity is smaller compared with the evaporation pond, the heat exchanges with the atmosphere more quickly, so it is influenced by the net radiation and diurnal temperature range greatly.

Key words: evaporation pan, evaporation pond, water surface evaporation, evaporation simulation, arid area, reservoirs in plain area