Journal of Spatial Analysis Environmental Hazards
تحلیل فضایی مخاطرات محیطی
Journal of Spatial Analysis Environmental Hazards
Literature & Humanities
http://jsaeh.khu.ac.ir
1
admin
2423-7892
2588-5146
10.61186/jsaeh
fa
jalali
1394
10
1
gregorian
2016
1
1
2
4
online
1
fulltext
fa
بررسی تغییرات زمانی -مکانی تپههای ساحلی ماسهای با استفاده از سنجشازدور (RS) مورد مطالعه: منطقه غرب زرآباد
A Survey on Spatial–temporal Changes of Coastal Sand Dunes Using Remote Sensing (RS). Case Study: West of Zarabad Region
تخصصي
Special
پژوهشي
Research
<p dir="RTL" style="margin-right: 9.65pt; text-align: justify;"><span style="font-size:16px;"><span style="font-family: nasimyw;"><strong>سالانه</strong> <strong>حجم</strong> <strong>عظیمی</strong> <strong>از ماسههای</strong> <strong>بادی،</strong> <strong>مناطق</strong> <strong>مسکونی</strong> <strong>و</strong> <strong>روستاها</strong> <strong>را</strong> <strong>مورد</strong> <strong>هجوم</strong> <strong>قرار</strong> <strong>میدهند.</strong> <strong>در</strong> <strong>برخی</strong> <strong>از</strong> <strong>روستاها</strong> <strong>که</strong> <strong>در</strong> <strong>مسیر حرکت</strong> <strong>ماسهها</strong> <strong>قرار</strong> <strong>دارند،</strong> <strong>مقدار</strong> <strong>حجم</strong> <strong>رسوبات</strong> <strong>بهگونهای</strong> <strong>است</strong> <strong>که</strong> <strong>سبب</strong> <strong>دفن</strong> <strong>واحدهای</strong> <strong>مسکونی</strong> <strong>شده</strong> <strong>و روستاییان</strong> <strong>بهناچار مجبور</strong> <strong>به</strong> <strong>ترک</strong> <strong>روستاها</strong> <strong>و</strong> <strong>خانههای</strong> <strong>خود</strong> <strong>شدهاند. هدف</strong> <strong>از</strong> <strong>این</strong> <strong>پژوهش حاضر با دیدگاهی جدید و کاملاً متفاوت از بقیه پژوهشها، درواقع به دنبال آشکارسازی تغییرات فضایی - زمانی تپههای</strong> <strong>ماسهای در منطقه ساحلی غرب زرآباد (کنارک)</strong> <strong>بوده</strong> <strong>است. پژوهش حاضر برای رسیدن به هدف ذکرشده ازلحاظ هدف کاربردی و ماهیت روششناسی بر مبنای روش، توصیفی </strong><strong>–</strong><strong> تحلیلی و از طریق شیوه مطالعه کتابخانه­ای- اسنادی و پیمایشی برای تحقیق در منطقه روستایی غرب زرآباد پرداخته شد. در</strong> <strong>این</strong> <strong>تحقیق برای بررسی </strong> <strong>تغییرات فضایی- زمانی</strong> <strong>تپه ماسهای</strong> <strong>منطقه غرب زرآباد،</strong> <strong>در</strong> <strong>دوره</strong> <strong>زمانی</strong> <strong>۲۳</strong> <strong>ساله</strong> <strong>(۲۰۱۴-1991) از </strong> <strong>نقشههای</strong> <strong>زمینشناسی،</strong> <strong>تصاویر ماهوارهای</strong> <strong>،</strong><span dir="LTR">GPS</span><strong>، استفاده گردید </strong><strong>و بهوسیله </strong><strong>روش­های سیستم اطلاعات جغرافیایی(</strong><span dir="LTR">GIS</span><strong>)، و نرمافزار (</strong><span dir="LTR">ENVI</span><strong>) </strong><strong> مورد تجزیهوتحلیل قرار گرفت.</strong> <strong>نتایج حاصل از گسترش تپههای ماسهای نشان میدهد که در سال 1991 تا 2014 مساحت کاربری که به نفع تپه­های ماسه­ای تغییر کاربری یافته­اند، عبارتاند از پوشش گیاهی حدود 108/0 کیلومترمربع، رسوبات رودخانه­ای 60/10 کیلومترمربع و زمین­های بایر 35/264 کیلومترمربع بود</strong><strong>ه­ا</strong><strong>ند. همچنین بیشترین تغییر مساحت مربوط به تپه­های ماسه­ای بوده که در سال 1991 (25/561) کیلومترمربع بوده و در سال 2014(45/578) کیلومترمربع رسیده و رشدی معادل (198/ 17) کیلومترمربع را </strong><strong>داشته</strong><strong> است. </strong></span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">Iran is among 10 top potential countries of occurrence of natural hazards in the world and from among 35 natural hazards, so far about 30 hazards have occurred in Iran(Negaresh and Latifi,2009). One of the different types of natural hazards which every year causes a lot of damage particularly in arid and arid regions of the world is the existence of sandy hills(Omidwar,2006); sandy hills are mostly created in coastal regions of most seas and oceans. These hills are the result of mutual effects of waves, marine currents, wind and sediments available in coastal regions. They are implemented with components of the coastal environment and construct the eco-systemic bases in which there are valuable collection flora and fauna(Kidd, 2001). The studied region is among the deserts near Gulf of Oman coasts. Sand on the coast are with marine origins and by getting far from the sea, sandy hills, in addition to having marine origins, have land origins. In some seasons of the year, particularly in summers and falls in which Monsoon winds start blowing up, the range of the movement of running sands is more towards rural regions in such a way that annually, a large part of sands covers residential areas, farmlands, road & building facilities, and infrastructural facilities in the rural areas of the west of Zarabad and left behind heavy damages and losses. The aim of this study is the detection of temporal-spatial changes in sand dunes in the Gulf of Oman coastal region. In addition, trend and severity of this hazard and the effects of climatic and environmental factors that intensified dimensions of risk were considered.</span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">The present study, to achieve the mentioned objective is an applied study and in terms of research, a method is a descriptive-analytical one. To collected data, it uses library-documentary as well as survey studies in the rural areas of the west of Zarabad. After that, to investigate the changes of the degree of displacement in dunes of the studied region in the 23 year time period (1991-2014), GPS and the Enhance Thematic Mapper Plus (ETM<sup>+</sup>) images of the Landsat Satellite 7 and 8 with the spatial resolution of 15 and 30 m were used. The satellite images were used in this study with time intervals of 10 and 13 years were related to years of 1991, 2001, and 2014 in August respectively and they were extracted from USGS.The ENVI software and Geographic Information System were used for images processing and interpretation. The geometric and radiometric corrections were applied on images according to standard procedures. Finally, classification and related calculation were performed.</span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">The conducted studies in the region based on the interpretation of satellite images and survey studies indicated that changes in the available users in the region, the top increases for dunes occurred in 1991 as 561.25 km<sup>2</sup>, in 2001 as 568.10 km<sup>2</sup>, and in 2014 as 575.45 km<sup>2</sup>. In fact, it has experienced a growth as 17.198 km<sup>2</sup>. The vegetation whose area covers 32 km<sup>2</sup> in 1991, in 2014 has reached an area with 45km<sup>2</sup> and increased as 1.6% compared to the previous period. In 1990 to 2014, the area of the user which has been changed in favor of dunes, includes 0.108 km<sup>2</sup> vegetation, 10.60 km<sup>2</sup> stream sediment, and 264.35 km<sup>2</sup> arid lands. Therefore, dunes move with high speed after each storm and during these displacements, a lot of damages are imposed on farmlands, facilities, and rural settlements. Investigating the degree of imposed damages indicates that annually, a large area of regions such as villages, roads, and facilities are influenced by running sands, which this trend can cover more regions in future years. The degree of displacement of dunes, according to the analyses conducted during the research period(1990-2014), has been so great that it has caused the burial of a large number of villages, infrastructure, farmland and roads and resulted in the unemployment of a large number of farmers in the region. Imposed damages to rural settlements have not been less than agricultural sectors and facilities. Therefore, due to the movement of running sands during recent years, 15 villages have been at the exposure of damages in such a way that compensation of these damages has imposed heavy costs, and consumed a lot of time on the shoulder of the society. As a result, the movement of dunes towards studied villages, i.e. Biahi, Mashkouhi, Abd, Rig Mostafa, Kalirak, Kerti, and Gati which are in the coastal regions, and Sohraki, Ganjak, Tanban, Zahrikar, and Kaidar which are located at far distances from the coast suffer from the highest amount of dunes and are considered as the most critical regions in terms of the movement of sand dunes. The results also showed that the important factors on severity and development of these critical regions are: a shortage of precipitation , loose and fine-grained sediments, low slope, no obstructions against the marine winds and high frequencies of winds and storms in this region.On the other hand, the lack of any varieties of vegetation on dunes, as well as the drought of recent years confirms spatial-temporal changes in the sand dunes towards the study area.</span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">In this research, the hazards due to running sands in the West region of Zarabad (Baluchestan) were studied. The results from satellite image interpretation and field works were showed that the greatest change of land cover in recent years was related to sand hills. The total areas of sand dunes in 1990 are 561 km²,in 2001 these area increases to 568 km² and finally in 2014 reached to 578.5 km².The average growth rate is about 0.76 km² per year. The landcover change from river sediments and barren land to sand dunes, during this period are estimated 10 and 264 km².</span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">The storm and marine winds moving sand dunes and running sands from coastal regions to rural settlements,farmland,Roads and other Infrastructures of the region. This hazard was just too much damage like buried villages, the destruction of roads and unemployment and migration of farmers. The number of evacuated villages are 15 cases that some of these villages is located in the coastal region(Biahi,Mashkohi,Abd,Kalirak……..) and others in inland(Soharaki,Ganjak,Tanbalan,…..).</span></span></p>
<p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family: times new roman;">This is the manifestation of crisis and instability in the rural communities that creating important obstacles to development and it is triggered vulnerable rural development was decreased.</span></span></p>
غرب زرآباد, تپههای ماسهای, سنجشازدور, تغییرات زمانی – مکانی, دریای عمان
Zarabad region, Sand dunes, Remote Sensing, Spatial–temporal changes, Gulf of Oman
1
14
http://jsaeh.khu.ac.ir/browse.php?a_code=A-10-3-30&slc_lang=fa&sid=1
Mahmood
Khosravi
محمود
خسروی
Khosravi@Gep.usb.ac.ir
1003194753284600949
1003194753284600949
Yes
Samad
Fotohi
صمد
فتوحی
1003194753284600950
1003194753284600950
No
Soliman
Pirouzzadeh
سلیمان
پیروزاده
1003194753284600951
1003194753284600951
No