Ecology, Environment and Conservation Paper

A NEW MODEL FOR ASSESSING OF LIVESTOCK PRESSURE A CASE STUDY- SOUTHERN IRAN

Masoud Masoudi and Elham Asrari

Abstract

Overgrazing can cause degradation of soil and vegetation. Therefore, the intensity of grazing can serve as an index of environmental pressure. The Mond river basin, located in the Southern Iran, has been selected as a test area to assess livestock pressure. For this purpose two sub basins of the Payab and Qareh Aghaj have been chosen for detailed study as these two provide enough variation in climatic conditions like rainfall and topography. The data analyzed have been gathered from the records and published reports of the Ministries of Agriculture and Defense and the Statistic Center of Iran. The present paper examines to find a model for assessing the pressure of livestock for the studied area using the Geographical Information System (GIS). FAO/ UNEP (1984) proposes the use of a ratio of potential carrying capacity to present livestock density as an estimate of pressure of livestock. This method has been adopted for the present study but with some modifications to achieve a better estimate of pressure related to the actual conditions of the area. Local parameters which have been used to modify this methodology are: annual consumption for livestock unit in the study area, dependency of each livestock to pasture, number of livestock unit for each animal, land use map and role of topography. Hazard maps of pressure of livestock were prepared after overlying and calculating the different parameters in a GIS. Results show that the areas under severe and very severe are observed more in the Payab (72 % of total land) than in eQareh Aghaj (36% of total land), indicating worse conditions in the Payab which forms lower reaches of Mond basin. The high pressure in the eastern part of Qareh Aghaj and most parts of Payab is related more to the lower potential of forage production and not to the numbers of livestock. This can be related more to worse conditions of natural parameters like soil and climate which decrease the potential of biomass production.