Decision support for irrigation system improvement in saline environment

Secondary salinisation in irrigated lands of arid regions is causing universal concern because of its implication on food security and environment. The problem however, is amenable to solution through implementation of suitable irrigation efficiency improving measures to minimise groundwater accessions. A methodology was developed for planning irrigation system improvement strategies in irrigated areas underlain by saline water aquifers with a rising groundwater table. The two important components of the methodology are: (1) simulation of groundwater behaviour which is accomplished through a two-dimensional finite difference groundwater model; and (2) development of appropriate irrigation system improvement plans that would minimise groundwater accretions. The second goal was achieved by formulating a multi-objective optimisation model. Application of the simulation model to a part of the Lower Ghaggar Basin (LGB) in the command of Bhakra Canal System (BCS) indicates waterlogging in more than 50% of the area within 10 years if no irrigation improvements are made. The multi-objective management model specifies priorities for implementing the best management activities in different parts of the project area. The suggested approach has potential applications to other land areas.