AWAM-A model for optimal land and water resources allocation

The planning for irrigation water management in an irrigation scheme consists of the preparation of an allocation plan for distribution of land and water resources to different crops up to tertiary or farm level, and water delivery schedules in terms of timing and amount of water delivery for this allocation plan according to the set objectives/targets. It is necessary to consider the heterogeneity in soils and climate, and complexity of the water distribution network, while developing the allocation plans. Further, there is a need to allocate water both efficiently and equitably. Preparation of the allocation plan becomes a complex process when the water availability is less than the demand for water for adequate irrigation of the culturable command area of the irrigation scheme. In the past, several methodologies have been developed to prepare allocation plans but these models do not consider the above-mentioned requirements together. This paper presents the developed model, AWAM (Area and Water Allocation Model) that addresses the heterogeneity in an irrigation scheme and includes the performance measures of productivity and equity while developing the allocation plans. The AWAM model has four phases to be executed separately for each set of irrigation interval over the irrigation season. The paper briefly discusses the applicability of the AWAM model by producing land and water allocation plans and water delivery schedules for case study of Nazare medium irrigation scheme in southern India.