Reclamation Information Sharing Environment (RISE)

Different levels of complexity for representing hydrologic-irrigator interactions in planning models were investigated. A simplified approach in which irrigator decisions regarding fallowing and irrigating are modeled via reservoir operations and water delivery rules combined with irrigator logic that determines when fallowing is triggered was implemented. Water mass balance is employed to track water flows through the system including the evolution of groundwater storage. For an intermediate level of model complexity, we have proposed and outlined an approach for linking the WRIMS Simplified Model with the physical based IWFM Demands Calculator (IDC) for the representation of soil and root zone processes governing crop water use. Ongoing work by California DWR is aimed at the third level of model complexity through development of CVSOM, a dynamic physically-based model representing the salient physical process and the time-dependent interactions between them and the reservoir operations and water management decisions by irrigators regarding irrigation, fallowing, and groundwater pumping. Recommended future work is to implement the proposed linkage between the WRIMS Simplified Model and IDC, followed by a comprehensive comparison between the three levels of models to develop guidelines for the types of water management strategy questions that can be answered by each level of modeling.