ارزیابی عملکرد روش پردازش تصویر در تخمین میزان غلظت رسوبات معلق سطحی در مناطق ساحلی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار/ دانشگاه آزاد اسلامی جویبار

2 استادیار گروه کامپیوتر، دانشگاه آزاد اسلامی، واحد جویبار

چکیده

سنجش میزان غلظت رسوبات در سواحل در راستای تحقق طرح‌های مدیریت سواحل از اهمیت ویژه‌ای برخوردار است و جریان‌های ساحلی خصوصاً جریان‌هایی که در اثر شکست امواج در سواحل میانه ایجاد می‌شوند، یکی از مهم‌ترین پدیده‌ها در انتقال رسوبات و انتشار آلودگی‌ها در دریاها و محیط‌های ساحلی محسوب می‌شوند. در این تحقیق در مرحله نخست الگوی پیچیده این جریان‌ها در سواحلی با حالت میانه در شرایط آزمایشگاهی اجرا شد. سپس با استفاده از روابط تجربی حاکم، غلظت رسوبات در هر اجرا تحت مکانیزم تعلیق رسوبات در اثر حرکت تلاطمی ناشی از امواج شکست یافته مورد محاسبه قرار گرفت. در گام بعدی با استفاده از اصول پردازش تصویر در نرم‌افزار متلب ویژگی‌های رنگی تصاویر در اعماق و شرایط هیدرودینامیکی مختلف جهت تخمین میزان غلظت رسوبات معلق استخراج شد. نتایج اصلی این تحقیق بیانگر همبستگی بالای ویژگی‌های رنگی تصاویر بر اساس الگوریتم‌های ارائه‌شده در مدل‌های RGB و Grayscale با میزان غلظت رسوبات منطقه است. دقت نتایج ارائه‌شده در بخش‌های مختلف منطقه نزدیک به ساحل گویای این واقعیت است که از دقت نتایج مدل با حرکت به سمت صورت ساحل کاسته می‌شود و بیشترین برازش ویژگی‌های تصاویر و میزان غلظت رسوبات در ناحیه کم‌عمقی رؤیت شده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Evaluation of the Performance of the Image Processing Method in Estimating the Concentration of Surface Suspended Sediments in Coastal Zones

نویسندگان [English]

  • Azadeh Valipour 1
  • Hossein Shirgahi 2
1 Department of Marine Science and Technology, Jouybar Branch, Islamic Azad University, Jouybar, Iran.
2 Department of Computer Engineering, Jouybar Branch, Islamic Azad University, Jouybar, Iran.
چکیده [English]

Measuring the concentration of sediments on beaches is of particular importance in line with the implementation of beach management plans. Coastal currents, especially those caused by breaking waves on the intermediate beaches, are considered one of the most important phenomena in the sediments transport and pollutant emissions in seas and coastal environments. In this research, first the complex pattern of these currents was implemented in beaches with an intermediate state in laboratory conditions. Then, using the governing empirical formulas, the concentration of sediments in each run was calculated under the sediment suspension mechanism due to the turbulent movement caused by broken waves. In the next step, using image processing principles in the Matlab software, the color characteristics of the images at different depths and hydrodynamic conditions were extracted to estimate the surface Suspended Sediment Concentration. The main results of this research show the high correlation of the color features of the images with the concentration of sediments in the area based on the algorithms presented in the RGB and Grayscale models. The accuracy of the results presented in different parts of the near shore zone indicates the fact that the accuracy of the model results decreases by moving towards the beach face and the best fit of the features of the images and the amount of sediment concentration is seen in the shoaling region.

کلیدواژه‌ها [English]

  • suspended sediment concentration
  • intermediate beaches
  • image processing
  • nearshore zone
  • shoaling region

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