Estimates of Evaporation from Surface Water Bodies with SEBAL Algorithm using Remote Sensing Techniques (Case Study: Chahnimeh's Fresh Water Reservoirs of Sistan)

Freshwater lakes are considered one of limited water resources that in recent decades are faced with many problems of quality and quantity. Proper management of these resources requires accurate information of component of the water budget. Evaporation as most unknown term of water budget, have a large share of water losses. To have precise information on the spatial and temporal distribution contribute to principles of qualitative and quantitative planning at water resources. Chanimeh’s artificial reservoirs are located in the east part of the country, with an area 141 Km2 was selected as case study. In this research, evaporation rate were estimated by SEBAL model and using meteorological data and satellite images of MODIS. Pan method applied in the region was used as reference method. As a result, the mapping of evaporation by 25*250 m spatial resolution was obtained. In point compare SEBAL model results with pan observed amount, the model correlation coefficient R, 0.74 and the error average percentage, ±14.5 and RMSD is equal to 2.95 mm. The mean latent heat flux and evaporation in average daily rate for the 202th of Julian days of 2012 year from water surface are equal 308 W/m2 and 13 mm per day, respectively.