A planning support system for rangeland allocation in Iran with case study of Chadegan sub-region

Abstract

Overgrazing and untimely grazing are common on rangelands in Iran often because of land tenure ambiguities. For the same reason a considerable portion of the rangelands has been converted into farmland for rainfed cereal production. As a result, these rangelands are experiencing land degradation under the increasing pressure to support a growing population of people and livestock. Land tenure reform is perceived as one approach to improving the use and condition of Iranian rangelands. Changes in land tenure involve very complex decision-making that should lead to sustainable use of the land and contribute to the sustainable livelihood of present and future generations. This paper describes a planning support system developed for rangeland allocation in Iran to support the tenure-reform process. The system is composed of three modules: land evaluation module, district planning module and local planning module.

The land evaluation module works in a GIS environment and uses the FAO methodology for land evaluation, with emphasis on biophysical characteristics of the land-use system. Socio-economic factors in terms of the effect of human intervention on the current status of the land have also been taken into account. The district planning module comprises three sub-modules: planning sub-module, grazing sub-module, and a multi-criteria evaluation (MCE) sub-module. The planning sub-module is an optimisation model that examines the degree of realisation of various objectives of stakeholders and generates alternative solutions. For each alternative, the grazing capacity of the land is assessed (grazing sub-module). The MCE sub-module ranks the alternative solutions, taking into account their advantages and disadvantages. The outcome is a pattern of land use consistent with existing government policies and satisfying the needs and desires of the local population. The local planning module also comprises three sub-modules: land allocation sub-module, economically viable grazing enterprise sub-module, and a land improvement planning sub-module. The land allocation sub-module transforms the district land-use pattern into a local land-use plan. The economically viable grazing enterprise sub-module determines the appropriate size of the land holding for each household on each land-mapping unit. Finally, the land improvement planning sub-module provides information on the status and impact of the land improvement program.

This planning support system has been applied to the Chadegan sub-region in Iran to illustrate its potential as a decision-making tool. Three scenarios were defined at district level, in addition to the status quo: maximum benefit for farm households; minimum government subsidies; and maximum land cover, emphasizing environmental goals. Results suggest that maximum land cover is the preferred scenario with the highest income and carrying capacity, and lowest level of subsidisation. However, since it eliminates wheat production, this scenario it culturally less attractive.