In arid zone of Iran, there are huge accumulative of sandy hills. The local
name of these hills is "Rig". Scientists discussed the reason of this
accumulation, which is prevailing wind and topography. But this study
shows the local cyclones in warm seasons are the cause of the accumulation.
The case study is Band-e-Rig, which is located in Masile depression in south
of Qom playa. Variables in this research are sand size, morphology of sandy
hills and wind directions. The method of this research is analytic and
between three parameters simultaneously a relation is developed by the
method of presence and difference. The tools of ihis research are
topographic maps and aerial photos. The technique is the comparing field-work
data, statistics of daily wind and granolometery of the sand sizes.
Results show one local cyclone of low pressure is settled in south of Masile
playa in summer. Thus, the wind in the whole Masile depression is blowing
to this direction and also to this point. The wind with this direction carried
sand to this location and then accumulates the band-E-Rig in east of Kashan.