Evaluation of Chahnimeh Reservoirs Evaporation

In order to evaluate the actual evaporation from Chahnimeh reservoirs, which are located in the northeastern part of Sistan and Baluchestan province, the water budget method was used, based on the available data as one of the main methods for evaporation estimation. These reservoirs have an average depth of 15 m and average surface area of 41 km2 with a volume of more than 600 MCM. These are the main source of domestic water in the region. The water budget results showed that the average annual evaporation was about 2.9 m. The monthly evaporation pan measurements in the vicinity of the reservoirs, pan coefficient was calculated to be about 0.66. At the continuation of the research, several valid methods including the Penman equation and CRLE model (for shallow and deep water) were applied. Comparison of the annual results of the water budget method with the Penman equation shows that estimation is about 2.8 m for the Penman equation, with little errors. Also annual evaporation was estimated to be about 1.8 m with the CRLE model