The Effects of Rapid Caspian Sea-Level Fluctuations on the Miankaleh Barrier Coasts
Message:
Abstract:
The goal of this study was to study the geomorphologic response- type models of the coastline of Miankaleh Barrier to the rapid fluctuations of the Caspian Sea. In this regard, Landsat satellite imageries (the sensor: 4, 5, 7 and 8 series), historical maps, topography maps and multiple field works have been used. Based on quantitative documentation of historical changes in shoreline position in response to natural and human variables, eight geomorphic response-types were identified for classifying barrier coasts: (1) lateral movement, (2) advance, (3) dynamic equilibrium, (4) retreat, (5) in-place narrowing, (6) landward rollover, (7) breakup, and (8) rotational instability. Long-term (decades to centuries) monitoring of shoreline position over a spatial scale of 10 to 100 km provides a scientific basis for documenting process-response relationships that shape regional coastal morphodynamics. The results show that there are the six morphological-type models in the Miankaleh barrier region based on the eight geomorphologic-type models of McBride et al, 1995; such as lateral movement, advance, retreat, in-place narrowing, breakup and rotational instability. The results indicate that the advance and retreat morphological-type models are formed in the region during the rise and fall sea levels, respectively. In-place narrowing and breakup morphological-type models appear simultaneously with the rise in sea level, and the rotational instability model also appears when the sea level is reduced in the region. The lateral movement type model has also been developed during the sea level rise and fall periods. Also, the results show that the sea level during the period of 1214-1396 has experienced six Progradation-Retrogradation stages. The assessment of the satellite imageries and statistical data on sea level fluctuations indicate that the sea level has fallen back to 1374 and has dropped by about 1.5 meters. The rate of recession and the reduction of the level of surface between 1374 until 1396 were estimated at 6.8 cm per year. Despite the fact that on a large scale, the increase in the relative sea level water along the shore of the Miankaleh barrier is one of the most important factors controlling the occurrence of various geomorphic reactions; however, the sediment supply also has a significant impact on reactions shoreline.
Article Type:
Research/Original Article
Language:
Persian
Published:
Journal of Physical Geography, Volume:11 Issue: 40, 2018
Pages:
1 - 16
magiran.com/p1894894  
برخی از خدمات از جمله دانلود متن مقالات تنها به مشترکان مگیران ارایه می‌گردد. شما می‌توانید به یکی از روش‌های زیر مشترک شوید:
اشتراک شخصی
در سایت عضو شوید و هزینه اشتراک یک‌ساله سایت به مبلغ 400,000ريال را پرداخت کنید. همزمان با برقراری دوره اشتراک بسته دانلود 100 مطلب نیز برای شما فعال خواهد شد!
پرداخت با کارتهای اعتباری بین المللی از طریق PayPal امکانپذیر است.
اشتراک سازمانی
به کتابخانه دانشگاه یا محل کار خود پیشنهاد کنید تا اشتراک سازمانی این پایگاه را برای دسترسی همه کاربران به متن مطالب خریداری نمایند!
توجه!
  • دسترسی به متن مقالات این پایگاه در قالب ارایه خدمات کتابخانه دیجیتال و با دریافت حق عضویت صورت می‌گیرد و مگیران بهایی برای هر مقاله تعیین نکرده و وجهی بابت آن دریافت نمی‌کند.
  • حق عضویت دریافتی صرف حمایت از نشریات عضو و نگهداری، تکمیل و توسعه مگیران می‌شود.
  • پرداخت حق اشتراک و دانلود مقالات اجازه بازنشر آن در سایر رسانه‌های چاپی و دیجیتال را به کاربر نمی‌دهد.