خلاصة:
The physical development of cities is always faced with natural barriers. The physical development of the city of Zabol, located in the Sistan plain, is threatened specifically with the development of sand dunes. For this reason, the region’s drought conditions were investigated and the standardized precipitation index was calculated. The results showed that with the drying of Hamoon Lake, the frequency of dust storms has increased. Zabol weather station’s anemometer data was collected, then annual and seasonal sand speed as well as the region’s prevailing weather pattern, which was drawn using Integrated Data Viewer (IDV), Wind Rose Plots (WRPLOT) and Sand Speed Graph software. The results showed that the dominant wind direction is from the North West, followed by the North winds. In addition, it was found that frequent strong winds are more important during the spring and summer. The results of drawing sand speed showed that the final direction for carrying sand is to the Southeast and the that wind's features have provided the conditions for the formation and development of active dunes. It should be noted that the development of Zabol is toward the North and Northwest. In addition, the prevailing wind direction of the region and the active sand dunes are to the North and the Northwest of Zabol. Thus, it is evident that one of the major barriers of the physical development of Zabol is the movement of sand dunes, as the development of Zabol is in the same direction of regional winds.
ملخص الجهاز:
The impact of drought periods and wind erosion on the physical development of desert cities (Case Study: Zabol- Iran) A.
The results of drawing sand speed showed that the final direction for carrying sand is to the Southeast and the that wind's features have provided the conditions for the formation and development of active dunes.
In addition, the prevailing wind direction of the region and the active sand dunes are to the North and the Northwest of Zabol.
These dunes are dependent on the dominant wind regime in the region and the value of available sediment weight (Bagnold: 1941), such that if the wind is permanently blown in the same direction throughout the year and an insufficient amount of sand is provided to cover the earth surface completely, barchan dunes are created (Sauermann et al.
Models of dune evolution which incorporate vegetation utilize growth functions partly dependent on wind-driven sand transport rates with growth vigor to arrive to the results of dry or wet periods (Bel and Ashkenazy, 2014).
It can be shown that the frequency and volume of sand dunes in the Northwestern area of Zabol surpasses those in the North, and that is consistent with wind speed results.
In fact, according to the prevailing wind direction in the region, sand dunes are formed and are developing.
The results of reviewing and analyzing the wind characteristics in Zabol showed that the prevailing wind direction of the region and the direction of the moving and developing sand dunes are completely consistent with one another, and are from the North to the Northwest.