Nicolaescu, Ion, authorManole, Emilia, authorU.S. Committee on Irrigation and Drainage, publisher2020-05-132020-05-132000-06https://hdl.handle.net/10217/206732Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.A large irrigation scheme having thousands of water users within its command area should be managed as an integrated agricultural production system, capable to generate economic benefits. The irrigation scheme operation intensity is variable in time, depending mainly upon the actual climate conditions and real water demand of the potential customers. This operation intensity can be expressed as the ratio between the net water volume which was applied to the crops and integrally used for increasing agricultural yield, and the net water volume required to irrigate all of the crops within irrigation scheme, calculated for 50% probability level. Evidently, there is a certain water demand minimum level of the irrigation scheme (Dmin), under which, its operation shall not be able to generate profit. In order to calculate this limit (Dmin), the authors developed a model on the base of benefit/cost analysis involving: a specific cropping pattern, irrigation water and pumping water efficiencies, economic input and output due irrigation for every crop etc. There is not any economic reason to start the operation of an irrigation scheme as long as the actual water demand level is under (Dmin) value. On such reason, (Dmin) becomes a synthetic parameter that is able to describe the technique and economic state of an irrigation system. Rehabilitation and modernization works (R&M) should influence the (Dmin) value, in a sense of its decreasing, as long as the volume of applied actions will increase. Using (Dmin) concept in a case study, for three months continuous operation time, this parameter could be decreased by seven types of R&M actions, from the actual value (45%) to the minimum one (33%). This synthetic parameter (Dmin) seems to be a suitable and sensitive proceeding to establish the proper strategy of the rehabilitation and modernization actions for any irrigation system.born digitalCD-ROMsproceedings (reports)engCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text