تحلیلی بر آسیب‌پذیری روستاهای ساحلی دریای عمان در برابر حرکت ماسه‌های روان (مطالعه موردی: بخش لیردف شهرستان جاسک)

Introduction
Movement of sand dunes is an important natural threat in the Coast of Oman Sea. Now many rural settlements of the region are in threat, and vulnerability has caused heavy losses. The sand dunes are visible in the wide area and wind erosion occurs in a wide spatial scale. Wind erosion faces high intensity in the area, because of poor vegetation, low rainfall, dry soil, strong and continuous winds, smooth surface and low lands, low slope and the recent drought, and the moving gigantic volume of annual windy sands. Due to the severe sand storms and the recent droughts occurred in the region, the environment, region economy, people’s health, and rural life have been faced with noticeable damages and this can be effective in unfavorable condition of life environment of the South Seas. According to the studies, undertaken by the author in this field and the study of the population and the housing census, villages’ culture and regional maps, ,15 villages have been buried and discharged, on account of sand movement during the recent 30 years (1976-2006), besides, some of them are in the forced discharge. Vulnerability in this villages, is growing so continuously that the east of Jask can be considered as a critical view of wind erosion and sand dune movement in the region. The recognition and analysis of rural settlement is an important factor in contrasting of crisis of movement of sand dunes and rural development planning and can effectively help reduce losses from related fields of this phenomenon. In this study there is an attempt to identify and classify the view of vulnerability of the physical – spatial movement of sand dune in the villages of the region.

Methodology
The present study is an applied one and the methodology used to prepare this paper is composed of empirical, analytical, and descriptive methods. The statistical population in this study consists of total 55 coastal villages threatened by the movement of sand dune in Lirdaf district of Jask .The hierarchical analysis process (AHP) is used to weight factors and analyze the vulnerability of villages in the region. Data collection has been done by means of library and field studies such as observation, interviews and completing questionnaires.

Results
According to the results obtained through comparing the sub-factors and the related calculations, the climatic factors with the relative weight of 0/633 posse the highest significance coefficient and priorities on the identification of the vulnerable and at risk villages and besides, geomorphology factors with 0/26 relative weight and human factors with 0/105 relative weight are in the next priorities. According to the results obtained through comparing the sub criteria and the related calculations, the vegetation factors with 0/246 relative weight and effected facilities with the relative weight of 0/018 have, alternatively, the highest and lowest significant coefficient and priorities in the recognition of vulnerable villages. After executing the model, t the minimum number of vulnerabilities with 0/1257 and the maximum with 0/3085 was cleared. Therefore, the classification of vulnerability in the investigatory domain varies between 0/1257 and 0/3035. Thus, vulnerability is divided into three categories; these classification domains are: 1– Rural settlement with low vulnerability (0/1257 till 0/1417). 2– Rural settlement with moderate vulnerability (0/1477 till 0/1550). 3– Rural settlement with high vulnerability (0/2160 till 0/3085).


Conclusion
According to the results of prioritizing vulnerable villages with respect to the movement of sand dune with (AHP) model, we are faced with three categories: A. Rural settlement which are in the final assessment in the situation of low vulnerable (23 villages or 40 % of the total points of the study). B. Rural settlement which are in the final assessment in the moderate vulnerability situation (16 villages or 29 % of the total points of the study). Adopting contraptions in order to reach a balanced level of development in a short and medium term planning is recommended for these villages. C. Particular village settlement showing, according to the results analysis, a high degree of vulnerability (17village or 30 % of the total point of the study). As a matter of fact, all of the factors operate a systematic function to face many of rural settlements with a high risk of vulnerability; the influential factors play a much more effective role in these rural areas. Such villages are likely to face damages caused by movement of sand dune, therefore, a comprehensive management of development it is an unavoidable necessity. It seems that in some villages, there would be no remedy except undertaking studies, providing preliminaries of is necessary for displacement plans, integration, and accumulation.