DECISION-SUPPORT FOR IRRIGATION SYSTEM IMPROVEMENT IN SALINE ENVIRONMENT

Secondary salinisation in irrigated lands of arid regions is causing u niversal concern because of its implication on food security and envir onment. The problem however, is amenable to solution through implement ation of suitable irrigation efficiency improving measures to minimise groundwater accessions. A methodology was developed for planning irri gation system improvement strategies in irrigated areas underlain by s aline water aquifers with a rising groundwater table. The two importan t components of the methodology are: (1) simulation of groundwater beh aviour which is accomplished through a two-dimensional finite differen ce groundwater model; and (2) development of appropriate irrigation sy stem improvement plans that would minimise groundwater accretions. The second goal was achieved by formulating a multi-objective optimisatio n model. Application of the simulation model to a part of the Lower Gh aggar Basin (LGB) in the command of Bhakra Canal System (BCS) indicate s waterlogging in more than 50% of the area within 10 years if no irri gation improvements are made. The multi-objective management model spe cifies priorities for implementing the best management activities in d ifferent parts of the project area. The suggested approach has potenti al applications to other land areas.