بررسی تاثیر طوفان‌های گردوغبار بر پوشش گیاهی تالاب شادگان

نوع مقاله : مقاله پژوهشی

نویسندگان

استادیار، سازمان تحقیقات، آموزش و ترویج کشاورزی، پژوهشکده حفاظت خاک و آبخیزداری، تهران، ایران

10.22034/jewe.2020.246746.1414

چکیده

بررسی و شناخت تأثیر طوفان­های گردوغبار بر تغییرات پوشش گیاهی تالاب‌ها، می‌تواند منجر به اطلاعات کاربردی برای مدیریت بهینه آن‌ها شود. در این پژوهش با استفاده از آمار باد ایستگاه‌ هواشناسی اهواز، نمودارهای گلباد و گل­طوفان تهیه شد. سپس تغییرات پوشش گیاهی تالاب شادگان با استفاده از نقشه­های طبقه‌بندی‌شده شاخص تعدیل‌شده خاک-پوشش گیاهی (SAVI) حاصل از تصاویر ماهواره MODIS سال‌های 2002 تا 2011 تعیین و سپس روابط همبستگی تغییرات پوشش گیاهی با آمار طوفان‌های گردوغبار ایستگاه هواشناسی اهواز تحلیل شد. نتایج نشان داد که جهت بادهای غالب در منطقه از شمال غرب تا غرب بود و همبستگی بین تعداد روزهای همراه با گردوغبار در سال با درصد اراضی با پوشش گیاهی خوب با ضریب تبیین 47/0 و همبستگی بین غلظت مجموع گردوغبار و پوشش گیاهی با ضریب تبیین 58/0 نشان ­داد که گردوغبار بر درصد پوشش گیاهی منطقه بی‌تأثیر نبوده است. روند تغییرات بین میزان غلظت گردوغبار با پوشش گیاهی در یک، دو، سه، چهار و پنج ماه قبل از تهیه شاخص فوق به‌صورت کاهشی بود و رابطه بین غلظت گردوغبار یک ماه قبل با درصد پوشش گیاهی (شاخص SAVI) با ضریب 99/0 بیش­ترین همبستگی را نشان داد. اثر منفی و معنی­دار طوفان­های گرد و غبار بر پوشش گیاهی، اهمیت موضوع را در تالاب بین‌المللی شادگان دوچندان می­کند و از طرفی استفاده از تصاویر ماهواره‌ای می­تواند اطلاعات دقیقی را با صرف هزینه و زمان کم­تر جهت مدیریت منابع پوشش گیاهی و آب و خاک در اختیار مدیران قرار دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of dust storms effect on vegetation cover of Shadegan wetland

نویسندگان [English]

  • Reza Bayat
  • Fazel Iranmanesh
  • Rahim Kazemi
Assist. Professor, Soil Conservation and Watershed Management Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
چکیده [English]

Investigating and understanding the impact of dust storms on wetland vegetation changes can lead to useful information for their optimal management. In this study, the wind rose and hurricane rose diagrams of the research area were prepared using wind statistics of Ahvaz meteorological stations. Changes in vegetation cover of Shadegan wetland were determined using classified soil-adjusted vegetation index (SAVI) maps of MODIS satellite images from 2002 to 2011 and correlations of vegetation changes were analyzed using dust storms data of Ahvaz meteorological station. The results showed that the major winds in the region flow from northwest to west and have the ability to create dust. The trend of changes of the number of stormy days, the concentration of dust and vegetation, were proportional to each other. The correlation between the number of dust days per year and the percentage of area with good vegetation cover showed relatively good relationship (the coefficient of determination was 0.47). The correlation between total dust concentration and vegetation cover, with a coefficient of determination of 0.58, indicated the high effect of dust on vegetation cover in the study area. The trend of changes in dust concentration with vegetation index was decreasing in one, two, three, four, and five months before image date. The relationship between dust concentration one month ago and vegetation percentage (SAVI index) with a coefficient of 0.99 showed the highest correlation. The negative and significant effect of dust storms on vegetation doubles the importance of the issue in Shadegan International Wetland, and on the other hand, the use of satellite images can provide accurate information with less cost and time to manage vegetation water and soil resources for managers.

کلیدواژه‌ها [English]

  • Hurricane rose
  • MODIS
  • satellite images
  • SAVI index
  • Wind rose
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