Unified Framework for Water Balance and Hydrologic Simulation:Part I-Theoretical Development

In this paper a unified framework is proposed to dovetail water balance model into a hydrologic simulation model. The additive and depletive nature of process operations, including the requirement for feedback and retraction, are discussed. The need to breakdown lumped processes into constituent elemental processes for water balance is discussed. The development of storage-process interaction matrix and its convergence towards water balance model are presented. The formulation of WAPROS model and its capability to generate storage-based water balance, process-based water balance, storage-level closure error, model-level closure error and water balance ratios, besides other hydrologic processes are outlined. The distinctions between model error and simulation error and the effects of interactions between them are also highlighted. A hierarchy of errors ‘simulation error-model error-storage closure error’ is proposed for error handling in simulation modelling. In this paper, theoretical development of unified framework is explained.