Reservoir level modeling is important for the operation of dam reservoir, design of hydraulic structures, determining pollution in reservoir and the safety of dam. In this study, daily reservoir levels for Millers Ferry Dam on the AlabamaRiver in USA were predicted using artificial neural networks (ANN)
IntroductionReservoir level is a complex index of natural water exchange within their watersheds. Longterm level fluctuations in natural (unregulated) lakes and large dam reservoirs also reflect climate change occurring in the region. Dams are also the most important fresh water sources and their construction is very expensive. Reservoir level fluctuations are also important not only in the planning, designing, and operating the fresh water reservoir made for any purpose (i.e. domestic, industrial, hydropower, and irrigation water supply as well as flood control, navigation, and water quality and quantity improvement) but also in all hydraulic structures. Therefore, they must be well planned and operated for the maximum return benefits. Level measurements or their future equally likely replicas obtained through a estimation model are a direct way of obtaining lake management decision variable. Although it is possible to identify sophisticated models taking into consideration the hydrological and hydro meteorological parameters such as the precipitation, runoff, humidity and temperature, it is economically preferred if a model that simulates the level variations on the basis of past level records is at the hand of the decision maker whether he/she be administrator, local authority or a technical operator (Sen et al. [1]).Reservoir water level forecasting at various time intervals using the records of past time series is an important issue in water resources planning (engineering, etc.). Variations in reservoir level are complex outcomes of many environmental factors, such as precipitations, direct and indirect runoffs from neighbor catchments, evaporation from free water body, air and water temperature, and interactions between the reservoir and the low lying aquifers. Although it is possible to identify sophisticated models taking into consideration the aforementioned parameters, it is preferable that a model which simulates lake-level variations based on previously recorded lake levels be available for research as well as practical purposes.Recently, the use of artificial intelligence (AI) methods such as artificial neural networks (ANNs), adaptive neuro-fuzzy has been accepted as an appropriate tool for modeling complex nonlinear phenomena in hydrology and water resources systems, leading to widening of their applications. In this context,