Planning water resources in dry lands using a non-linear optimization model

Abstract

A methodology was developed for identifying and planning the water resources use in dry lands. A data base was constructed with information of small basins which were identified using the ARCVIEW 3.2 software. Meteorological information was used to estimate run-off and to calculate the potential water volume that could be accumulated in each identified site. Subsequently, a non linear optimization model was used to determine the crop pattern that maximizes the net benefit according to the physical, environmental and economic resources and constraints. The sensibility analysis of the model indicated that the most important variables were product price, water availability, labor hand availability and irrigation method efficiency. It was also determined that small basins are more sensible than medium or big basins. An appropriate intervention strategy for dry lands is to introduce adapted species to these conditions and to use captured water for supplementary irrigation in the few months with high water demand. The idea is not to transform the whole area in an irrigation zone, but from its limitations and potentialities to plan a rational use of the water that can be captured in winter.