abstract in this study the comparative advantage of wheat in sistan was investigated by using drc index and policy analysis matrix (pam) during 2006-2007. data were collected from zabol agri-jahad organization and annual foreign trade database. the npc index showed that there was an indirect tax on producers in all sectors. epc index represented that there were nonsupport of input and output ma...

iran is located in dry belt of the earth and always involved with drought in different sections. drought has already caused many losses to natural plant cover, agriculture and human society. for drought monitoring, we can use some drought indecies. in this research, the standard index of annual precipitation)siap),sandardized precipitation index (spi) and palmer drought severity index (pdsi) we...