Hazard assessment of livestock pressure in Khuzestan province, Iran

Overgrazing accelerates soil and vegetation degradation in rangelands. This study aimed to assess livestock pressure on natural resources of Khuzestan province, located in the south western part of Iran, using Geographic Information System (GIS) tools and a model-based procedure. FAO/UNEP Model which uses a ratio of potential carrying capacity of region to current livestock population density as an Index for livestock pressure was selected for this purpose. However, the model was modified in this study to achieve a better estimation of pressure index according to the actual conditions of the region. Parameters used to modify this methodology were: Topographic and Local parameters. Local parameters were annual consumption for livestock unit in the study area, dependency of each livestock to pasture, number of livestock unit for each animal and land use map. Hazard map of pressure of livestock was prepared after overlying and calculating different parameters in a GIS. According to the results, hazard classes of severe and very severe included about 70% of natural resources in the study area. Areas including higher classes of hazard severity were identified in the west, center and south east part of the region, mostly. This is because of low potential of natural rangeland to grow enough forage and also a high number of livestock