عنوان مقاله [English]
The effective management of available water for irrigation in arid region like Iran has become increasingly important due to limited water supply. The need for irrigation water allocation in water limiting condition caused to use GIS in order to manage information optimally and to have easy access. In the present study, the objective was to develop a planning support system to be adaptable to the existing condition of water delivery and distribution and operational systems of irrigation networks in which to determine irrigation timing and amount of water that is needed to be available for the planted crops. This model was written in Visual Basic language and in using data banks it takes advantage of ACCESS software and execution is performed in ArcGIS 9.3 environment. To calculate irrigation water needed to be allocated to every irrigation block, four steps were designed to be taken into account in the model. The steps include crop and soil parameters, first order canal capacity parameters, and second and third order canal capacity and gates parameters. Finally, model evaluates irrigations was done for each crop in each block.