A graphical rule for volumetric evaporation loss correction in reservoir capacity-yield-performance planning in Urmia region, Iran

The loss of stored water from surface water reservoirs through evaporation is inevitable and can be significant in arid and semi-arid climates. One way of compensating for this inevitable loss is to explicitly include the evaporation process in the reservoir planning analysis, thus ensuring that the resulting capacity estimate will be capable of meeting both the intended consumptive demands and the evaporative losses. However, because evaporation measurements are often unavailable and because there are few reservoir planning techniques that can explicitly accommodate evaporation consideration, this solution is often not applied. The result is that there is currently little guidance regarding the allowance for evaporation losses during reservoir planning in such regions. This study has used data from the Urmia region in Iran to develop a rule for evaporation correction during reservoir planning. The way to use the rule is explained and suggestions about how the study can be extended are offered. © 2004 Kluwer Academic Publishers.