Modeling the Limitative Factors of Forage Production Suitability Using GIS (Case Study: Aliabad Rangelands, Lorestan, Iran)

Abstract

This research was conducted to identify the limitative factors of forage production<br />suitability in order to achieve the sustainable exploitation of natural ecosystems in Aliabad<br />Watershed in Lorestan in 2013. The field measurements have been done through cutting and<br />weighing method to estimate the forage amount, four-factor method to determine the range<br />condition, trend scale to specify the orientation and appearance, the plant cover percent<br />measurement to categorize the types and desert scroll to separate the land units followed by<br />the classification. At last, all the digital maps of type, orientation, condition and forage<br />production by the help of integration were changed into the final forage production suitability<br />map using specific software ArcGIS 9.3. Results indicate that 6 separated vegetation types<br />have been put in the suitability classes of S1, S2 and S3 for the areas of 972 ha (20.02%),<br />3478 ha (71.62%) and 406 ha (8.36%), respectively and no part of the given rangelands was<br />placed in non-suitability class (N). Considering the results obtained from final suitability<br />model of range production in this study, it has been found that high slope was the most<br />restricting factor of range suitability. In addition, there were other decreasing factors such as<br />low percentage of vegetation, overgrazing, early grazing, nonconformity of livestock and<br />rangeland balance and changes of ranges into low-yielding dry lands' farming as well as<br />forage production. It was concluded that the accuracy, simplicity and quickness can be<br />considered as fundamental elements to determine the range suitability using Geographical<br />Information System (GIS) which has been addressed in this study.