Furrow irrigation design with multicriteria analysis

Abstract

This study describes an application of the SADREG decision support system to cotton furrow irrigation in Central Fergana Valley, Uzbekistan. This application aims at modernizing furrow irrigation and is based upon field trials on crop water requirements and surge irrigation. A large number of design alternatives were generated for a typical field, which were compared in terms of water use, irrigation water productivity, irrigation costs and yield value. This comparison has shown that alternatives that favour water use performance are different from those leading to higher farm incomes. For multicriteria analysis, three different prioritization schemes were analysed, one relative to economic results, another referring to water saving, and the third representing a balanced situation between the two. Very different rankings resulted, with alternatives ranked high for economic results being ranked low for water saving, and vice-versa. The high ranked alternatives for the balanced prioritization scheme are common to the other two, but the decision demands further consideration of risk factors and users’ preferences. This application shows that adopting water saving technologies and deficit irrigation is generally difficult in economic terms, thus requiring support to farmers if their income is to be maintained.