Application of a hydraulic model for testing management decisions at distributary level

✍ Scribed by M. N. Bhutta; J. W. Kijne

• Publisher: Springer
• Year: 1992
• Tongue: English
• Weight: 558 KB
• Volume: 13
• Category: Article
• ISSN: 0342-7188
• DOI: 10.1007/bf00190240

✦ Synopsis

A computer model "MISTRAL" was adopted for evaluating management options. The study showed that the model can be used as a decision support tool for prioritizing management options. The model suggests that under current physical conditions of this distributary the combination of rotation between the distributaries and along the distributary canals can improve the equity of water discharge. For example, in case of Lagar Distributary the discharge of tail outlets can be increased threefold by introducing rotation between the tail of the distributary and an offtaking minor canal. A small decrease in the discharge of the minor would result from adopting this option. A combination of rotations between this and neighboring distributaries and along the Lagar itself can increase the discharge of tail outlets up to seven times. The results of the model indicate that operational changes can improve the discharge of tail outlets to some extent, but the improvement of physical conditions of the distributary is needed to achieve equity conditions, as specified in the design.

The irrigation system in the Indus basin in Pakistan was designed in an environment in which land was less scarce than water. It was, therefore, designed to provide reasonable protection against the effects of severe droughts for the maximum number of people. This called for equitable water allocation and delivery of water. The size of the system was relatively large (now approximately 14 million hectares of cultivable command area) for the extent of its actual irrigated area, resulting in a proportionately larger physical infrastructure relative to cropped area than systems designed for production objectives. This has significant implications for an understanding of the irrigation problems identified at the present time.