Multilevel approach for optimizing land and water resources and irrigation deliveries for tertiary units in large irrigation schemes: 1: Method

This paper presents the area and water allocation model (AWAM), which incorporates deficit irrigation for optimizing the use of water for irrigation. This model was developed for surface irrigation schemes in semi arid regions under rotational water supply. It allocates the land area and water optimally to the different crops grown in different types of soils up to the tertiary level or allocation unit. The model has four phases. In the first phase, all the possible irrigation strategies are generated for each cropsoil- region combination. The second phase prepares the irrigation program for each strategy, taking account of the response of the crop to the water deficit. The third phase selects the optimal and efficient irrigation programs. In the fourth phase of the model irrigation programs are modified by incorporating the conveyance and the distribution efficiencies. These irrigation programs are then used for allocating the land and water resources and preparing the water release schedule for the canal network.