On-going Development of the ACRU Agrohydrological Model
ACRU is a multipurpose model that integrates water budgeting and runoff components of the terrestrial hydrological system with risk analysis, and can be applied in crop yield modeling, design hydrology, reservoir yield simulation and irrigation water demand/supply, regional water resources assessment, planning optimum water resource allocation and utilization, climate change, land use and management impacts, and resolving conflicting demands on water resources. The ACRU model uses daily multilayer soil water budgeting and has been developed essentially into a versatile total evaporation model. It has therefore been structured to be highly sensitive to climate and to land cover/use changes on the soil water and runoff regimes, and its water budget is responsive to supplementary watering by irrigation, to changes in tillage practices, or to the onset and degree of plant stress.
Design Rainfall and Flood Estimation
The estimation of design rainfall and floods, where the magnitude of a rainfall or flood event is associated with a level of risk (e.g. return period are necessary for the design of hydraulic structures (e.g. bridges, culverts, dam spillways, drainage canals) and thus to quantify and limit the risk of failure of the structures. Accurate design flood estimationis necessary in the planning, design and operation of hydraulic structuresfor the preservation of human life and property.
Uncertainties in Modelling
Modelling of hydrological processes encapsulates our limited understanding of natural processes and is necessary for planning and management of water resources. However, many uncertainties are inherent in hydrological modelling, including uncertainty about knowledge, natural variability and decision uncertainty and these uncertainties need to be incorporated into decision making.