Application of aerial photographs and satellite images for visualization of forest cover changes (Case study: Zagros forests, Iran)

Document Type : Research article

Authors

1 Ph.D. student, Faculty of Natural Resources, University of Tehran

2 Professor, Faculty of Natural Resources, University of Tehran

3 Assistant Prof., Faculty of Natural Resources, University of Tehran

Abstract

Visualization is one of the best methods to represent data from natural environments. In this research, the variation of the forest cover was visualized at a part of Zagros forests (741 hectare) using aerial photographs and satellite images. Geometric correction and relief displacement was done on 1997 aerial photographs. Aerial photographs of 1955 and 1969 were corrected by approximate image correction method using georefrenced images. Forest boundaries were determined on all of the images by visual interpretation techniques, However classification of 1997 aerial photographs and satellite image were done automatically using Maximum likelihood classifier. Aerial photographs of 1955 and 1969 were classified by dot grid. Shadow index was specified by determining the accurate canopy amount on 74 random trees and compare them with data deduction from images. Likewise, field data were collected using 141 circular 1200m sample plots in a systematic random grid (100m×300m). With preparation of essential data, visualizations were done on different scale in the 3DNature software. Results indicated the notable reduce of forest area (37%) since 50 years ago. Maximum amount of canopy drop (45%) have been occurred from 1955 to 1969. Canopy percent on forest region indicate ascending trend (+15%) from 1969 to 1997 and lightly descending trend from 1997 to 2003.

Keywords

References

- حجاریان، م.، 1384. بررسی تغییرات کمی جنگلهای مانگروی جزیره قشم با استفاده از عکس های هوایی و تصاویر ماهواره‌ای. پایان‌نامه کارشناسی‌ارشد، دانشکده منابع طبیعی دانشگاه تهران، 123 صفحه.
- زبیری، م.، 1384. آماربرداری در جنگل. انتشارات دانشگاه تهران، چاپ سوم، 401 صفحه.
- سوسنی، ج. و محمدعلیزاده، خ.، 1386، بررسی میزان رویش قطری درختان شاخه­زادبلوط ایرانی (مطالعه موردی: جنگلهای محدوده شهرستان خرم­آباد). گزارش نهایی طرح تحقیقاتی، دانشگاه لرستان، 137 صفحه.
- طهماسبی‌پور، م.، 1374. بررسی مناسبترین ابعاد شبکه آماربرداری و سطح قطعه نمونه برای دقت معین در جنگلهای بلوط غرب کشور. پایان‌نامه کارشناسی‌ارشد، دانشگاه تهران، 87 صفحه.
- عرفانی‌فرد، س.ی.، زبیری، م.، فقهی، ج. و نمیرانیان، م.، 1386. برآورد سطح تاج‌پوشش جنگل در عکسهای هوایی با استفاده از شاخص سایه در زاگرس. فصلنامة تحقیقات جنگل و صنوبر ایران، 15(3): 288- 278.
Bai,Y., Walsworth, N., Roddan, B., Hill,D.A., Broersma, K. and Thompson, D., 2005. Quantifying tree cover in the forest–grassland ecotone of British Columbia using crown delineation and pattern detection. Forest Ecology and Management, 212: 92-100.
Buckley, D.J., Ulbricht, C. and Berry, J., 1998. Advanced 3D Visualization Techniques for Forest Management and Research. The ESRI 1998 User Conference, July 27 - 31 1998. San Diego, CA, 11 p.
Dunbar, M.D., 2004. 3D Visualization for the Analysis of Forest Cover Change. Kansas Applied Remote Sensing (KARS) Program and Department of Geography, 9 p.
http://en.wiktionary.org/wiki/visualization.
McCormick, B.H., Thomas, A. and Maxine, D., 1987. Visualization in Scientific Computing. ACM SIGBIO Newsletter,10 (1): 15 - 21. 
McGaughey, R. 1998. Techniques for visualizing the appearance of forestry operations. Journal of Forestry, 96 (6): 9–14.
Sachs, D.L., Phillip, S. and Cohen, W.B., 1998. Detecting landscape changes in the interior of British Columbia from 1975 to 1992 using satellite imagery. Canadian Journal of Forest Research, 28(1): 23-36.
Tufte, E.R., 1983. The Visual Display of Quantitative Information. Graphics Press, Cheshire, Connecticut 14 p.
www.googleearth.com 

Files

Share

How to cite

Statistics