The simple answer is that climate is perhaps the primary determinant of the viability of evaporation ponds for any specific use. Beyond that simple statement, though, a number of variables are in play. Natural evaporation occurs under all climate conditions. However, it is the rate of evaporation that is critical to the effectiveness of a large-scale outdoor evaporation pond that will be efficient and cost-effective for commercial or industrial purposes. Although there are ways to warm water in a pond to prevent freezing, and other methods can be employed to speed evaporation chemically, those methods are not always practical.
Relative humidity is the most important factor that determines the rate of evaporation. Other factors include solar radiation, air and water temperature and wind. Warmer air holds water vapor more effectively than cool air, but it can become saturated quickly, so windy conditions are considered favorable for optimal effectiveness of evaporation ponds. Plankton blooms or suspended soil particles help absorb solar radiation, and they are considered helpful to promote evaporation. The salinity of the water also has an effect. Seawater typically has an evaporation rate that is about five percent less than fresh water. While in some cases, plants can help with evaporation, any plant growth that covers the water surface with leaves, including lotus, water lilies or duckweed, tend to reduce surface water evaporation.
