The Water Balance and Stable Isotope Hydrology of Lake Edward, Uganda-Congo

Lake Edward, Uganda-Congo, is one of the least studied of the great lakes of East Africa, and little is known of its physical hydrology. Stable isotope data and modeling and previously published estimates of Lake Edward's water balance are used to constrain the physical hydrology of the lake, and particularly the relative proportion of surface outflow to evaporative water losses. Stable isotope calculations suggest that Lake Edward loses roughly 50% of its water income by evaporation, while reviews of published hydrologic data together with our calculations suggest that evaporation comprises 54% of water losses. The similarity of these two sets of calculations lends credence to their validity, and provides a new water budget for the lake. Our results have important implications for the chemistry and hydroclimatic sensitivity of Lake Edward.